H1 domain found in potassium channel tetramerization domain-containing proteins; The H1 domain is found in potassium channel tetramerization domain-containing proteins such as KCTD8, KCTD12 (also called predominantly fetal expressed T1 domain/Pfetin), KCTD12b, and KCTD16. They serve as auxiliary gamma-aminobutyric acid type B (GABA-B) receptor subunits that constitute receptor subtypes with distinct functional properties. KCTD12 and -12b generate desensitizing receptor responses while KCTD8 and -16 generate largely non-desensitizing receptor responses. They control GABA-B signaling and regulate the rise time and duration of G protein-coupled inwardly rectifying potassium (GIRK) currents, as well as enhance receptor expression levels. KCTD12 regulates agonist potency and kinetics of GABA-B receptor signaling. It promotes tumorigenesis by facilitating CDC25B/CDK1/Aurora A-dependent G2/M transition. KCTD16 interacts with amyloid beta precursor protein (APP), a type I transmembrane protein involved in a variety of cellular processes such as cell adhesion and axon guidance. Members of this family consist of an N-terminal BTB domain followed by a region called the H1 domain. The BTB domain mediates interaction with the receptor. The C-terminal H1 domain, which possesses a beta-propeller-like fold, engages in interactions with G-protein beta-gamma subunits and is responsible for desensitization. This model corresponds to the H1 domain.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 124249324 162 RITLSGDKSLIEEVFpeiGDVMCNSVNAGWNHDSTHVIRFPLNgYCHLNsvQVLERLQQRGFEIVGSCGGGVDS------ 235
Cdd:cd22204   29 RILVCGKVSLCREVF---GDTLNESRDPDRGEPDRYTSRFFLK-HNYLE--QAFDQLAEAGFRLVASCGSGTSGlpsagd 102

                         90
                 ....*....|....*.
gi 124249324 236 ------SQFSEYVLRR 245
Cdd:cd22204  103 seekrwNHYTEFVFVR 118

BTB/POZ domain; In voltage-gated K+ channels this domain is responsible for subfamily-specific assembly of alpha-subunits into functional tetrameric channels. In KCTD1 this domain functions as a transcriptional repressor. It also mediates homomultimerization of KCTD1 and interaction of KCTD1 with the transcription factor AP-2-alpha.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 124249324   40 VHIDVGGHMYTSSLATLTKYPESRIGRLFDgTEPIVLDSLKQHYFIDRDGQMFRYILNFLRTS-KLLIPDDfKDYTLLYE 118
Cdd:pfam02214   1 VKLNVGGTRFETLKSTLTRFPDTRLGRLLE-LECDDYDDDTNEYFFDRSPKHFETILNFYRTGgKLHRPEE-VCLDEFLE 78

                          90
                  ....*....|....
gi 124249324  119 EAKYFQLQPMLLEM 132
Cdd:pfam02214  79 EAEFYGLDELALEL 92

H1 domain found in potassium channel tetramerization domain-containing proteins; The H1 domain is found in potassium channel tetramerization domain-containing proteins such as KCTD8, KCTD12 (also called predominantly fetal expressed T1 domain/Pfetin), KCTD12b, and KCTD16. They serve as auxiliary gamma-aminobutyric acid type B (GABA-B) receptor subunits that constitute receptor subtypes with distinct functional properties. KCTD12 and -12b generate desensitizing receptor responses while KCTD8 and -16 generate largely non-desensitizing receptor responses. They control GABA-B signaling and regulate the rise time and duration of G protein-coupled inwardly rectifying potassium (GIRK) currents, as well as enhance receptor expression levels. KCTD12 regulates agonist potency and kinetics of GABA-B receptor signaling. It promotes tumorigenesis by facilitating CDC25B/CDK1/Aurora A-dependent G2/M transition. KCTD16 interacts with amyloid beta precursor protein (APP), a type I transmembrane protein involved in a variety of cellular processes such as cell adhesion and axon guidance. Members of this family consist of an N-terminal BTB domain followed by a region called the H1 domain. The BTB domain mediates interaction with the receptor. The C-terminal H1 domain, which possesses a beta-propeller-like fold, engages in interactions with G-protein beta-gamma subunits and is responsible for desensitization. This model corresponds to the H1 domain.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 124249324 162 RITLSGDKSLIEEVFpeiGDVMCNSVNAGWNHDSTHVIRFPLNgYCHLNsvQVLERLQQRGFEIVGSCGGGVDS------ 235
Cdd:cd22204   29 RILVCGKVSLCREVF---GDTLNESRDPDRGEPDRYTSRFFLK-HNYLE--QAFDQLAEAGFRLVASCGSGTSGlpsagd 102

                         90
                 ....*....|....*.
gi 124249324 236 ------SQFSEYVLRR 245
Cdd:cd22204  103 seekrwNHYTEFVFVR 118

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing proteins, KCTD1 and KCTD15; This subfamily of KCTD proteins includes KCTD1 and KCTD15. KCTD1 is a nuclear BTB/POZ domain-containing protein that acts as a transcriptional repressor and mediates protein-protein interactions through a BTB domain. It represses the transcriptional activity of AP-2 family members, including TFAP2A, TFAP2B and TFAP2C. It also functions as a novel inhibitor of the Wnt signaling pathway. Mutations in KCTD1 cause scalp-ear-nipple (SEN) syndrome. KCTD15 is a BTB/POZ domain-containing protein that plays a role in the regulation of neural crest (NC) formation and other steps in embryonic development. It inhibits AP2 transcriptional activity by interaction with its activation domain. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization. The KCTD1 BTB domains form pentamers.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 124249324  40 VHIDVGGHMYTSSLATLTKYPESRIGRLFDGTEPIVLDSLKQHYFIDRDGQMFRYILNFLRTSKLLIPDDFKDYTLLYEE 119
Cdd:cd18361    1 VHIDVGGHIYTSSLETLTKYPESRLGKLFNGSIPIVLDSLKQHYFIDRDGKMFRHILNFLRTSKLLLPDDFTEFDLLYEE 80

                         90
                 ....*....|....
gi 124249324 120 AKYFQLQPMLLEME 133
Cdd:cd18361   81 ARYYELQPMVKQLE 94

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 6 (KCTD6); KCTD6, also called KCTD containing, Cullin3 adaptor, suppressor of Hedgehog 3 (KCASH3), is a BTB/POZ domain-containing protein that functions as a substrate-specific adaptor of cullin-3, regulating protein levels of the muscle small ankyrin-1 isoform 5 (sAnk1.5) as well as suppressing histone deacetylase and Hedgehog activity in medulloblastoma. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 124249324  39 PVHIDVGGHMYTSSLATLTKYPESRIGRLFDGTEPIVLDSlKQHYFIDRDGQMFRYILNFLRTSKLLIPDDFKDYTLLYE 118
Cdd:cd18394    4 PVTLNVGGHLYTTSLSTLTRYPDSMLGAMFRGDFPTARDS-QGNYFIDRDGPLFRYILNFLRTSELTLPVDFKEFDLLRK 82

                         90
                 ....*....|.
gi 124249324 119 EAKYFQLQPML 129
Cdd:cd18394   83 EADFYQIEPLI 93

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 21 (KCTD21); KCTD21, also calledz KCTD containing, Cullin3 adaptor, suppressor of Hedgehog 2 (KCASH2), is a BTB/POZ domain-containing protein that functions as a substrate-specific adaptor of cullin-3, promoting the ubiquitination and degradation of histone deacetylase HDAC1, thereby inhibiting the deacetylation-mediated transcriptional activation of the Hedgehog effectors Gli1 and Gli2. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 124249324  39 PVHIDVGGHMYTSSLATLTKYPESRIGRLFDGTEPIVLDSlKQHYFIDRDGQMFRYILNFLRTSKLLIPDDFKDYTLLYE 118
Cdd:cd18395    2 PITLNVGGKLYTTSLATLTRYPDSMLGAMFSGKFPTKKDS-QGNCFIDRDGKIFRYILNFLRTSHLDLPEDFQEMGLLKR 80

                         90
                 ....*....|....*
gi 124249324 119 EAKYFQLQPMLLEME 133
Cdd:cd18395   81 EADFYQIQPLIEALQ 95

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 4 (KCTD4); KCTD4 is a BTB/POZ domain-containing protein with an unknown biological function. KCTD proteins play crucial roles in a variety of fundamental biological processes, such as protein ubiquitination and degradation, suppression of proliferation or transcription, cytoskeleton regulation, tetramerization and gating of ion channels and others. Some KCTD proteins are involved in protein ubiquitination as part of the CRL (Cullin RING Ligase) E3 ligases. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 124249324  40 VHIDVGGHMYTSSLATLTKYPESRIGRLFDGTEPIVLDSlKQHYFIDRDGQMFRYILNFLRTSKLLIPDDFKDYTLLYEE 119
Cdd:cd18364    2 VTLNVGGYLYITQRQTLTKYPDSFLEGMVNGKIQCTVDA-DGNYFIDRDGLLFRHVLNFLRNGELLLPEGFQENQLLALE 80

                 ....*.
gi 124249324 120 AKYFQL 125
Cdd:cd18364   81 ADFYQL 86

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Arabidopsis thaliana FH protein interacting protein FIP2 and similar proteins; FIP2 may act as a substrate-specific adaptor of an E3 ubiquitin-protein ligase complex (CUL3-RBX1-BTB) which mediates the ubiquitination and subsequent proteasomal degradation of target proteins. It contains a BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 124249324  40 VHIDVGGHMYTSSLATLTKYPESRIGRLFDGTEPIVLDSlKQHYFIDRDGQMFRYILNFLRTSKLLIP-DDFKDYTLLYE 118
Cdd:cd18376    1 VKLNVGGQKFTTTLDTLTKDPDSMLAAMFSGRHSLKKDE-DGSYFIDRDGTHFRHILNYLRDGEVKIPtEDRSVLKELLE 79

                 ....*....
gi 124249324 119 EAKYFQLQP 127
Cdd:cd18376   80 EAEYYQLRG 88

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein KCTD11; KCTD11 may function as an antagonist of the Hedgehog pathway of cell proliferation and differentiation by affecting the nuclear transfer of transcription factor GLI1, thus maintaining cerebellar granule cells in the undifferentiated state. It is a probable substrate-specific adapter for a BCR (BTB-CUL3-RBX1) E3 ubiquitin-protein ligase complex towards HDAC1. It contains a BTB/POZ domain; in some cases the domain may be truncated. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization. Variants of the human/mouse KCTD11 appear to contain truncated BTB/POZ domains.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 124249324  40 VHIDVGGHMYTSSLATLTKYPESRIGRLFDGTEPIVLDSLKQ---HYFIDRDGQMFRYILNFLRTSKLLIPDDFKDYTLL 116
Cdd:cd18370    1 VTLNVGGTLYSTTLETLTRFPDSMLGAMFRAGTPIPPNLNMQgggHYFIDRDGKAFRHILNFLRLGRLDLPRGYGETALL 80

                 ....*...
gi 124249324 117 YEEAKYFQ 124
Cdd:cd18370   81 RAEADFYQ 88

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 7 (KCTD7); KCTD7 is a BTB/POZ domain-containing protein that has an impact on K+ fluxes, neurotransmitter synthesis, and neuronal function. It functions as a regulator of potassium conductance in neurons, and is involved in the control of excitability of cortical neurons. Mutations in KCTD7 may cause progressive myoclonus epilepsy (PME). The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 124249324  40 VHIDVGGHMYTSSLATLTKYPESRIGRLFDGTEPIVLDSlKQHYFIDRDGQMFRYILNFLRTSKLLIPDDFKDytlLYEE 119
Cdd:cd18366    6 VPLNVGGMHFTTRLSTLRKYEDSMLAAMFSGRHHIPKDS-EGRYFIDRDGSYFGYILNFLRDGDLPPRERARA---VYKE 81

                         90
                 ....*....|
gi 124249324 120 AKYFQLQPML 129
Cdd:cd18366   82 AQYYGIGPLI 91

second BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 19 (KCTD19); KCTD19 is a BTB/POZ domain-containing protein with unclear biological function. It may be a host factor involved in Nef-induced downregulation of MHC-I. Nef is a HIV-1-encoded protein that plays a key role in the development of AIDS. KCTD19 contains two BTB domains. This model corresponds to the second domain. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 124249324  40 VHIDVGGHMYTSSLATLTKYPEsrigrLFDGTEPIVLDSLKQHYFIDRDGQMFRYILNFLRTSKLLIPDDFKDYTLLYEE 119
Cdd:cd18374    3 VKVYVGSHWYATYLKTLLKYPE-----LLSNSKKVRWITYGQTLLISGDGQMFRHILNFLRLGKLLLPSEFKEWPLLCQE 77

                         90
                 ....*....|..
gi 124249324 120 AKYFQLqPMLLE 131
Cdd:cd18374   78 VEEYQI-PALSE 88

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein KCTD8; KCTD8, a BTB/POZ domain-containing protein, is an auxiliary subunit of GABA-B receptors that determine the pharmacology and kinetics of the receptor response. It interacts as a tetramer with GABRB1 and GABRB2. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 124249324  40 VHIDVGGHMYTSSLATLTKYPESRIGRLFDGTEPIVL--DSlKQHYFIDRDGQMFRYILNFLRTSKLLIPDDFKDYTLLY 117
Cdd:cd18396    6 VELNVGGQVYVTKHSTLLSVPDSTLASMFSRRAARELprDN-RGRFFIDRDGFLFRYVLDYLRDKQLALPDHFPEKERLL 84

                         90
                 ....*....|..
gi 124249324 118 EEAKYFQLQPML 129
Cdd:cd18396   85 REAEYFQLGDLV 96

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in voltage-gated potassium (Kv) channels; Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. This family includes several groups of alpha subunits such as KCNA/Kv1 family of Shaker-type Kv channels, KCNB/Kv2 family of Shab-type Kv channels, KCNC/Kv3 family of Shaw-type Kv channels, KCND/Kv4 family of Shal-type Kv channels, KCNF/Kv5 subfamily of Kv channels, KCNG/Kv6 subfamily of Kv channels, KCNV/Kv8 subfamily of Kv channels, and KCNS/Kv9 subfamily of Kv channels. Kv alpha subunits form functional homo- or hetero-tetrameric channels (typically with other alpha subunits from the same subfamily) through their BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif. KCNQ/Kv7 channels are not included in this family, since they do not contain a BTB/POZ domain.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 124249324  40 VHIDVGGHMYTSSLATLTKYPESRIGRLFDGTEpiVLDSLKQHYFIDRDGQMFRYILNFLRTSKLLIPDDF 110
Cdd:cd18317    1 VVLNVGGTRFELSRSTLLRFPDTRLGKLAKESH--AYDESTNEYFFDRNPEVFEAILDYYRTGELHLPSNV 69

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in voltage-gated potassium (Kv) channels and potassium channel tetramerization domain-containing (KCTD) proteins; This family includes two protein groups: voltage-gated potassium (Kv) channels and potassium channel tetramerization domain-containing (KCTD) proteins. Kv channels are membrane proteins with fundamental physiological roles. They are responsible for a variety of electrical phenomena, such as the repolarization of the action potential, spike frequency adaptation, synaptic repolarization, and smooth muscle contraction. KCTD proteins play crucial roles in a variety of fundamental biological processes, such as protein ubiquitination and degradation, suppression of proliferation or transcription, cytoskeleton regulation, tetramerization and gating of ion channels, and others. All family members contain the BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 124249324  40 VHIDVGGHMYTSSLATLTKYPESRIGRLFDGTEPIVLDSLKQHYFIDRDGQMFRYILNFLRTSKLLIPDDFKDYTLLyEE 119
Cdd:cd18187    1 VVLNVSGTRFVTNRQTLTRHPDTLLGRMFKPGREFTFPNETGEYFIDRDPTVFRTILNYYRTGKLNCPDGISIPDLR-EE 79

                 ....
gi 124249324 120 AKYF 123
Cdd:cd18187   80 CDFY 83

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily V member 2 (KCNV2); KCNV2, also called voltage-gated potassium channel subunit Kv8.2, is a modulatory voltage-gated potassium channel alpha subunit that modulates channel activity by shifting the threshold and the half-maximal activation to more negative values. KCNV2 is essential for visual function and cone survival. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. KCNV2 is a regulatory alpha subunit that cannot form a functional homo-tetrameric channel. It forms hetero-tetrameric channels (with other functional alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 124249324  40 VHIDVGGHMYTSSLATLTKYPESRIGRLFDGTEPIVLDSL-------KQHYFIDRDGQMFRYILNFLRTSKLLIPDDFKD 112
Cdd:cd18425    1 LNINVGGTSYQISYRVAASYPKTRIGRLATYTDRSRKLDLcddynvqNDEYFFDRDPAVFHHIYNFYRTGVLWVKDELCP 80

                         90
                 ....*....|.
gi 124249324 113 YTLLyEEAKYF 123
Cdd:cd18425   81 RNFL-EEINYW 90

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in SH3KBP1-binding protein 1 (SHKBP1); SHKBP1, also called SETA-binding protein 1, interacts with cathepsin B and participates in tumor necrosis factor (TNF)-induced apoptosis in ovarian cancer cells. It can promote epidermal growth factor receptor (EGFR) signaling by interrupting c-Cbl-CIN85 complex and inhibiting EGFR degradation. It contains a BTB/POZ domain, also known as tetramerization (T1) domain, a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 124249324  40 VHIDVGGHMYTSSLATLTKYPESRIGRLFDGTEPIVLDSLKQhYFIDRDGQMFRYILNFLRTSKLLIPDdfKDYTLLYEE 119
Cdd:cd18393    4 IHLNVGGKRFSTSRQTLTWIPDSFFSSLLSGRISTLKDETGA-IFIDRDPTVFAPILNFLRTKELDPRG--IHVSLLLHE 80

                         90
                 ....*....|....
gi 124249324 120 AKYFQLQPMLLEME 133
Cdd:cd18393   81 AQFYGITPLVRRLQ 94

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 10 (KCTD10); KCTD10, also called BTB/POZ domain-containing adapter for CUL3-mediated RhoA degradation protein 3 (BACURD3), is a BTB/POZ domain-containing protein that interacts with proliferating cell nuclear antigen (PCNA) and polymerase delta, and participates in DNA repair, DNA replication, and cell-cycle control. Its down-regulation could inhibit cell proliferation. KCTD10 also plays crucial roles in embryonic angiogenesis and heart development in mammals by negatively regulating the Notch signaling pathway. Furthermore, KCTD10 may function as a substrate-specific adaptor of a BCR (BTB-CUL3-RBX1) E3 ubiquitin-protein ligase complex, which mediates the ubiquitination of target proteins, leading to their degradation by the proteasome. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization. The KCTD10 BTB domain forms a novel two-fold symmetric tetramer that is distinct from the tetramer formed by voltage-gated potassium (Kv) channels.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 124249324  34 TKSNAPVHIDVGGHMYTSSLATLTKyPESRIGRLFDGTEPIVLDSlKQHYFIDRDGQMFRYILNFLRTSKLLIPDDFKDY 113
Cdd:cd18399    3 SPSSKYVKLNVGGALYYTTMQTLTK-QDTMLKAMFSGRMEVLTDS-EGWILIDRCGKHFGTILNYLRDGAVPLPESRREI 80

                         90       100
                 ....*....|....*....|....*...
gi 124249324 114 TLLYEEAKYFQLQPMLLEMERWKQDRET 141
Cdd:cd18399   81 EELLAEAKYYLVQGLVEECQAALQNKDT 108

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 18 (KCTD18); KCTD18 is a BTB/POZ domain-containing protein with with unknown biological function. A duplication of the KCTD18 gene has been found in a patient with epilepsy, developmental delay, and autistic behavior, which may contribute to the phenotype. KCTD proteins play crucial roles in a variety of fundamental biological processes, such as protein ubiquitination and degradation, suppression of proliferation or transcription, cytoskeleton regulation, tetramerization and gating of ion channels and others. Some KCTD proteins are involved in protein ubiquitination as part of the CRL (Cullin RING Ligase) E3 ligases. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 124249324  40 VHIDVGGHMYTSSLATLTKYPESRIGRLFDGTEPIVLDSlKQHYFIDRDGQMFRYILNFLRtSKLLIPDDFKDYTLLYEE 119
Cdd:cd18372    3 LRLNVGGCIYTARRESLCRFKDSMLSSMFSGRFPLKLDE-SGACVIDRDGRLFKYLLDYLH-GELQIPEDEQTRLALQEE 80

                 ....
gi 124249324 120 AKYF 123
Cdd:cd18372   81 ADYF 84

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 3 (KCTD3) and SH3KBP1-binding protein 1 (SHKBP1); The group of KCTD proteins includes KCTD3 and SHKBP1. KCTD3, also called renal carcinoma antigen NY-REN-45, is a BTB/POZ domain-containing protein that is an accessory subunit of potassium/sodium hyperpolarization-activated cyclic nucleotide-gated channel 3 (HCN3), upregulating its cell-surface expression and current density without affecting its voltage dependence and kinetics. SHKBP1, also called SETA-binding protein 1, interacts with cathepsin B and participates in tumor necrosis factor (TNF)-induced apoptosis in ovarian cancer cells. It can promote epidermal growth factor receptor (EGFR) signaling by interrupting c-Cbl-CIN85 complex and inhibiting EGFR degradation. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 124249324  40 VHIDVGGHMYTSSLATLTKYPESRIGRLFDGTepivLDSLKQHY---FIDRDGQMFRYILNFLRTSKLLIPDdfKDYTLL 116
Cdd:cd18363    4 INLNVGGKRFSTSRQTLTWIPDSFFTSLLSGR----ISSLKDETgaiFIDRDPKLFSIILNYLRTKEIDLRN--VDISSL 77

                 ....*..
gi 124249324 117 YEEAKYF 123
Cdd:cd18363   78 RHEAEFY 84

first BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 19 (KCTD19); KCTD19 is a BTB/POZ domain-containing protein with unclear biological function. It may be a host factor involved in Nef-induced downregulation of MHC-I. Nef is a HIV-1-encoded protein that plays a key role in the development of AIDS. KCTD19 contains two BTB domains. This model corresponds to the first domain. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 124249324  41 HIDVGGHMYTSSLATLTKYPESRIGRlfdgtEPIVLD-SLKQHYFIDRDGQMFRYILNFLRTSKLLIpDDFKDYTLLYEE 119
Cdd:cd18373    2 YFNVGGWIFSVPKSKLAQFPDSLLWK-----EASSLSeSENTRLFIDRDGFTFRHVHYYLQTSKLSS-SSCSELNLLYEQ 75

                         90       100
                 ....*....|....*....|.
gi 124249324 120 AKYFQLQPMLLEMERWKQDRE 140
Cdd:cd18373   76 AAGLQLTSLLQALDNLKEGKH 96

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily S member 1 (KCNS1); KCNS1, also called delayed-rectifier K(+) channel alpha subunit 1 or voltage-gated potassium channel subunit Kv9.1, is a modulatory alpha subunit of voltage-gated potassium channel that mediates neuropathic pain following nerve injury. It can form functional heterotetrameric channels with KCNB1 (also known as Kv2.1) and KCNB2 (also known as Kv2.2), and further modulates the delayed rectifier voltage-gated potassium channel activation and deactivation rates of KCNB1 and KCNB2. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. KCNS1 is a regulatory alpha subunit that cannot form a functional homo-tetrameric channel. It forms hetero-tetrameric channels (with other functional alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 124249324  40 VHIDVGGHMYTSSLATLTKYPESRIGRLF--DGTEPIV-----LDSLKQHYFIDRDGQMFRYILNFLRTSKLLIPDDFKD 112
Cdd:cd18426    1 ININVGGLKRRLSSSTLSKFPDTRLGRLLscDSEESILqicddYDVSAKEFYFDRNPGLFPYVLHFYQTGKLHIMEELCV 80

                         90
                 ....*....|....*....
gi 124249324 113 YTlLYEEAKYFQLQPMLLE 131
Cdd:cd18426   81 FS-FSQEIEYWGINEFFLD 98

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in tumor necrosis factor, alpha-induced protein 1, endothelial (TNFAIP1); TNFAIP1, also called BTB/POZ domain-containing adapter for CUL3-mediated RhoA degradation protein 2 (BACURD2), or protein B12, is a BTB/POZ domain-containing protein that is involved in DNA replication, DNA damage repair and cell apoptosis, and is implicated in human diseases including cancer, Alzheimer's disease (AD) and type 2 diabetic nephropathy. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization. The BTB domains of other BACURD subfamily members, KCTD10 and KCTD13, form a novel two-fold symmetric tetramer that is distinct from the tetramer formed by voltage-gated potassium (Kv) channels.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 124249324  37 NAPVHIDVGGHMYTSSLATLTKYpESRIGRLFDGTEPIVLDslKQHY-FIDRDGQMFRYILNFLRTSKLLIPDDFKDYTL 115
Cdd:cd18401    2 NKYVRLNVGGSLYYTTVQVLTRH-DTMLKAMFSGRMEVLTD--KEGWiLIDRCGKHFGTILNYLRDDTVALPKSRQEIKE 78

                         90       100
                 ....*....|....*....|....*
gi 124249324 116 LYEEAKYFQLQPMLLEMERWKQDRE 140
Cdd:cd18401   79 LMAEAKYYLIQGLVDMCQAALQDKK 103

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Drosophila melanogaster potassium voltage-gated channel protein Shal and similar proteins; Drosophila melanogaster Shal, also called Shaker cognate l or Shal2, is a transient potassium current (I(A)) channel, which is required for maintaining excitability during repetitive firing and normal locomotion in Drosophila. It may play a role in the nervous system and in the regulation of beating frequency in pacemaker cells. Shal mediates the voltage-dependent potassium ion permeability of excitable membranes. Assuming opened or closed conformations in response to the voltage difference across the membrane, the protein forms a potassium-selective channel through which potassium ions may pass in accordance with their electrochemical gradient. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. Shal is an alpha subunit that forms functional homo- or hetero-tetrameric channels (with other alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 124249324  21 PLNNQGIPTPAQLTKSNAP----VHIDVGGHMYTSSLATLTKYPESRIGrlfDGTEPIVLDSLKQHYFIDRDGQMFRYIL 96
Cdd:cd18420   15 PIANNPLPPPPVDQERRRTddekLIINVSGRRFETWRNTLEKYPDTLLG---SNEREFFYDEETKEYFFDRDPDIFRHIL 91

                         90       100       110
                 ....*....|....*....|....*....|.
gi 124249324  97 NFLRTSKLLIPDDfKDYTLLYEEAKYFQLQP 127
Cdd:cd18420   92 NYYRTGKLHYPKH-ECLTAYDEELAFFGIMP 121

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 17 (KCTD17); KCTD17 is a BTB/POZ domain-containing protein that functions as a substrate-adaptor for cullin3-RING ubiquitin ligases that polyubiquitylates trichoplein, a protein involved in ciliogenesis down-regulation. It is a positive regulator of ciliogenesis, playing a crucial role in the initial steps of axoneme extension. A missense mutation in KCTD17 causes autosomal dominant myoclonus-dystonia (M-D). The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization. The KCTD17 BTB domains form pentamers.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 124249324  40 VHIDVGGHMYTSSLATLTKYPESRIGRLFDGTEPIVLDSLKQHYFIDRDGQMFRYILNFLRTSKLLIPDDFKDYTLLyEE 119
Cdd:cd18391    3 VRLNVGGTVFLTTRQTLCREQKSFLSRLCQGEELQSDRDETGAYLIDRDPTYFGPILNFLRHGKLVLDKDMAEEGVL-EE 81

                         90
                 ....*....|
gi 124249324 120 AKYFQLQPML 129
Cdd:cd18391   82 AEFYNIGPLI 91

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in KCNB/Kv2 subfamily of Shab-type voltage-dependent potassium channels; Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. The potassium voltage-gated channel subfamily Kv3, also known as subfamily C, contains two alpha subunit members, Kv2.1 (KCNB1) and Kv2.2 (KCNB2), which are orthologs of the Shab gene in Drosophila. They are delayed-rectifier potassium currents in various neurons, although their physiological roles often remain elusive. Kv2/KCNB subfamily alpha subunits form functional homo- or hetero-tetrameric channels (with other alpha subunits) through their BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 124249324  40 VHIDVGGHMYTSSLATLTKYPESRIGRLFDGT--EPIV-----LDSLKQHYFIDRDGQMFRYILNFLRTSKLLIPDD 109
Cdd:cd18378    4 VLLNVGGVRHEVLWRTLDRLPRTRLGRLRECNthESLLelcddYDLEDNEYFFDRHPGAFTSILNFYRTGKLHMPEE 80

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily S member 2 (KCNS2); KCNS2, also called delayed-rectifier K(+) channel alpha subunit 2 or voltage-gated potassium channel subunit Kv9.2, is a modulatory alpha subunit of voltage-gated potassium channel that can form functional heterotetrameric channels with KCNB1 (also known as Kv2.1) and KCNB2 (also known as Kv2.2), and further modulates the delayed rectifier voltage-gated potassium channel activation and deactivation rates of KCNB1 and KCNB2. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. KCNS2 is a regulatory alpha subunit that cannot form a functional homo-tetrameric channel. It forms hetero-tetrameric channels (with other functional alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 124249324  40 VHIDVGGHMYTSSLATLTKYPESRIGRLFD--GTEPIV-----LDSLKQHYFIDRDGQMFRYILNFLRTSKL 104
Cdd:cd18427    2 ISINVGGFKKRLRSHTLLRFPETRLGRLLScrSKESILelcddYDDTKNEFYFDRNPELFPYVLHFYNTGKL 73

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in KCNG/Kv6 subfamily of potassium voltage-gated channels; Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. The potassium voltage-gated channel subfamily Kv6, also known as subfamily G, includes KCNG1 (Kv6.1), KCNG2 (Kv6.2 or KCNF2), KCNG3 (Kv6.3) and KCNG4 (Kv6.4), which are regulatory alpha subunits and do not form functional channels on their own. KCNG1 can form functional heterotetrameric channels with KCNB1 (also known as Kv2.1), and further modulates the delayed rectifier voltage-gated potassium channel activation and deactivation rates of KCNB1. KCNG2, also called cardiac potassium channel subunit, can form functional heterodimeric channels with KCNB1, and further modulates channel activity by shifting the threshold and the half-maximal activation to more negative values. KCNG3, also called voltage-gated potassium channel subunit Kv10.1, is an electrically silent modulatory subunit that can form functional heterotetrameric channels with KCNB1, and further promotes a reduction in the rate of activation and inactivation of the delayed rectifier voltage-gated potassium channel KCNB1. KCNG4 is a silent voltage-gated potassium (KvS) channel subunit that can form functional heterotetrameric channels with KCNB1, and further modulates the delayed rectifier voltage-gated potassium channel activation and deactivation rates of KCNB1.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 124249324  42 IDVGGHMYTSSLATLTKYPESRIGRL--FDGTEPIV-----LDSLKQHYFIDRDGQMFRYILNFLRTSKL 104
Cdd:cd18382    3 INVGGARYSLPWSTLDRFPLTRLSRLkaCRSEDDILrvcddYDVERNEFFFDRSPEAFGVILLFLRAGKL 72

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 5 (KCTD5); KCTD5 is a BTB/POZ domain-containing protein that functions as a substrate adaptor for cullin3 based ubiquitin E3 ligases. It is a negative regulator of the AKT pathway, a key signaling cascade frequently deregulated in cancer. KCTD5 does not impact the operation of Kv4.2, Kv3.4, Kv2.1, or Kv1.2 channels. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization. KCTD5 forms pentamers mediated by its BTB domain.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 124249324  40 VHIDVGGHMYTSSLATLTKYPESRIGRLFDGTEPivLDSLKQH---YFIDRDGQMFRYILNFLRTSKLLIPDDFKDYTLL 116
Cdd:cd18390    7 VRLNVGGTYFLTTRQTLCRDPKSFLYRLCQADPD--LDSDKDEtgaYLIDRDPTYFGPVLNYLRHGKLVINKDLAEEGVL 84

                         90
                 ....*....|...
gi 124249324 117 yEEAKYFQLQPML 129
Cdd:cd18390   85 -EEAEFYNITSLI 96

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Drosophila melanogaster potassium voltage-gated channel protein Shab and similar proteins; Shab is a slow delayed rectifier voltage-gated potassium channel in Drosophila. It mediates transmembrane potassium transport in excitable membranes. Assuming opened or closed conformations in response to the voltage difference across the membrane, the protein forms a tetrameric potassium-selective channel through which potassium ions may pass in accordance with their electrochemical gradient. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. Shab is an alpha subunit that forms functional homo- or hetero-tetrameric channels (with other alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 124249324  37 NAPVHIDVGGHMYTSSLATLTKYPESRIGRLFDGT--EPIV-----LDSLKQHYFIDRDGQMFRYILNFLRTSKLLIPDD 109
Cdd:cd18413    1 NRRVVINVGGVKHEVLWRTLDRMPHTRLGKLRDSNthEAIVelcddYSLADNEYFFDRHPRSFASILNFYRTGKLHLVEE 80

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily G member 4 (KCNG4); KCNG4, also called voltage-gated potassium channel subunit Kv6.4, is a silent voltage-gated potassium (KvS) channel subunit that can form functional heterotetrameric channels with KCNB1 (also known as Kv2.1), and further modulates the delayed rectifier voltage-gated potassium channel activation and deactivation rates of KCNB1. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. KCNG4 is a regulatory alpha subunit that cannot form a functional homo-tetrameric channel. It forms hetero-tetrameric channels (with other functional alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 124249324  40 VHIDVGGHMYTSSLATLTKYPESRIGRL--FDGTEPIV-----LDSLKQHYFIDRDGQMFRYILNFLRTSKLLI 106
Cdd:cd18423    4 IIINVGGIKYLMPWSTLDEFPLTRLGKLkfCSSYEEIVqicddYDEDTNEFFFDRNPCAFRMIVSFLAAGKLRL 77

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily A member 4 (KCNA4); KCNA4 is also called HPCN2, or voltage-gated K(+) channel HuKII, voltage-gated potassium channel HBK4, voltage-gated potassium channel HK1, or voltage-gated potassium channel subunit Kv1.4. It mediates transmembrane potassium transport in excitable membranes. Assuming opened or closed conformations in response to the voltage difference across the membrane, the protein forms a tetrameric potassium-selective channel through which potassium ions may pass in accordance with their electrochemical gradient. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. KCNA4 is an alpha subunit that forms functional homo- or hetero-tetrameric channels (with other Kv1/KCNA alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 124249324  40 VHIDVGGHMYTSSLATLTKYPESRIGRLFDGTEpiVLDSLKQHYFIDRDGQMFRYILNFLRTSKLLIPDDFKDYTLLYEE 119
Cdd:cd18405    3 VVINVSGLRFETQLKTLAQFPETLLGDPEKRMR--YFDPLRNEYFFDRNRPSFDAILYYYQSGGRLKRPVNVPFDIFSEE 80

                 ....*.
gi 124249324 120 AKYFQL 125
Cdd:cd18405   81 VKFYEL 86

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily B member 1 (KCNB1); KCNB1, also called delayed rectifier potassium channel 1 (DRK1) or voltage-gated potassium channel subunit Kv2.1, mediates transmembrane potassium transport in excitable membranes, primarily in the brain, but also in the pancreas and cardiovascular system. Assuming opened or closed conformations in response to the voltage difference across the membrane, the protein forms a tetrameric potassium-selective channel through which potassium ions may pass in accordance with their electrochemical gradient. KCNB1 is involved in the regulation of the action potential (AP) repolarization, duration and frequency of repetitive AP firing in neurons, muscle cells and endocrine cells and plays a role in homeostatic attenuation of electrical excitability throughout the brain. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. KCNB1 is an alpha subunit that forms functional homo- or hetero-tetrameric channels (with other alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 124249324  40 VHIDVGGHMYTSSLATLTKYPESRIGRLFD-GTEPIVLDSLKQH------YFIDRDGQMFRYILNFLRTSKL 104
Cdd:cd18411   12 VKLNVGGLAHEVLWRTLDRLPRTRLGKLRDcNTHESLMEICDDYnleeneYFFDRHPGAFTSILNFYRTGKL 83

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily A member 5 (KCNA5); KCNA5, also called HPCN1, voltage-gated potassium channel HK2, or voltage-gated potassium channel subunit Kv1.5, mediates transmembrane potassium transport in excitable membranes. Assuming opened or closed conformations in response to the voltage difference across the membrane, the protein forms a tetrameric potassium-selective channel through which potassium ions may pass in accordance with their electrochemical gradient. KCNA5 may play a role in regulating the secretion of insulin in normal pancreatic islets. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. KCNA5 is an alpha subunit that forms functional homo- or hetero-tetrameric channels (with other Kv1/KCNA alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 124249324  40 VHIDVGGHMYTSSLATLTKYPESRIG------RLFDgtepivldSLKQHYFIDRDGQMFRYILNFLRT-SKLLIP----- 107
Cdd:cd18406    3 VIINIAGLRFETQLGTLNQFPDTLLGdpdkrmRYFD--------PLRNEYFFDRNRPSFDGILYFYQSgGKIRRPvnvsi 74

                         90       100       110
                 ....*....|....*....|....*....|.
gi 124249324 108 DDFKDytllyeEAKYFQLQPMllEMERWKQD 138
Cdd:cd18406   75 DVFAD------EIRFYQLGEE--AMERFRED 97