Alternative titles; symbols
HGNC Approved Gene Symbol: WASHC5
SNOMEDCT: 785305006;
Cytogenetic location: 8q24.13 Genomic coordinates (GRCh38): 8:125,024,260-125,091,792 (from NCBI)
| Location | Phenotype |
Phenotype MIM number |
Inheritance |
Phenotype mapping key |
|---|---|---|---|---|
| 8q24.13 | Ritscher-Schinzel syndrome 1 | 220210 | Autosomal recessive | 3 |
| Spastic paraplegia 8, autosomal dominant | 603563 | Autosomal dominant | 3 |
The WASHC5 gene encodes strumpellin, a 134-kD protein that is ubiquitously expressed in cytosolic and endoplasmic reticulum cell fractions (summary by Clemen et al., 2010).
By sequencing clones obtained from an immature myeloid leukemia cell line cDNA library, Nagase et al. (1996) cloned KIAA0196. The deduced 1,159-amino acid protein contains putative transmembrane domains. Northern blot analysis detected KIAA0196 expression in all tissues and cell lines examined, with highest expression in skeletal muscle.
Clemen et al. (2010) found ubiquitous expression of the KIAA0196 gene in all human tissues analyzed. The protein was primarily present in cytosolic and endoplasmic reticulum membrane fractions. In the human hippocampus and ventral spinal cord, it colocalized with the presynaptic protein synaptophysin (SYP; 313475).
Porkka et al. (2004) used microarray analysis, quantitative RT-PCR, and FISH to identify genes that were amplified and overexpressed in prostate cancer (176807). They found that KIAA0196, RAD21 (606462), and CHRAC1 (607268) were amplified in several prostate cancer cell lines and hormone-refractory prostate tumors. However, only amplification of KIAA0196 was associated with overexpression in tumor samples.
The product of the KIAA0196 gene is the protein strumpellin (Valdmanis et al., 2007).
In immunoprecipitation studies, Clemen et al. (2010) identified strumpellin as a binding partner with VCP (601023), mutation in which causes inclusion body myopathy with early-onset Paget disease, with or without frontotemporal dementia (IBMPFD1; 167320). Strumpellin was detected in pathologic protein aggregates in muscle tissue derived from patients with IBMPFD1 as well as in various myofibrillar myopathies and in cortical neurons of a mouse model of Huntington disease (HD; 143100). These findings suggested that strumpellin may have a role in various protein aggregate diseases. Both knockdown and overexpression of wildtype KIAA0196 caused a significant decrease in wound healing velocity in an in vitro-based assay. ShRNA knockdown of KIAA0196 in human neuroblastoma cells caused a reduction in axonal outgrowth.
Jia et al. (2010) stated that WASH (WASHC1; 613632) localizes to endosomal subdomains and regulates endocytic vesicle scission in an ARP2/3 (see 604221)-dependent manner. Using affinity purification, immunoprecipitation, and knockdown experiments, Jia et al. (2010) found that WASH, FAM21 (see 613631), SWIP (WASHC4; 615748), strumpellin, and CCDC53 (WASHC3; 619925) formed a high-affinity WASH regulatory core complex (SHRC) in human, cow, and fly. Immunofluorescence analysis in transfected HeLa cells showed that SHRC subunits colocalized with each other and with a subset of EEA1 (605070)-positive endosomes, similar to endogenous WASH. Using recombinant proteins, the authors found that the SHRC inhibited intrinsic WASH activity toward the ARP2/3 complex. The N-terminal coiled-coil domain of WASH was required for association with all components of the SHRC. The conserved helical domain of CCDC53 was necessary and sufficient for association of CCDC53 with all other SHRC components and could stabilize WASH in HeLa cell lysates. The C terminus of SWIP mediated interaction with strumpellin. The N-terminal domain of FAM21 interacted with all components of the SHRC, whereas the C-terminal domain of FAM21 interacted directly with CAPZ (see 601580) and inhibited its anti-capping activity. Moreover, the C-terminal domain of FAM21 interacted directly with phospholipids and phosphatidylserine, potentially linking the SHRC to endosomal domains enriched in phospholipids.
The KIAA0196 gene contains 28 exons and spans 59.7 kb of genomic DNA (Valdmanis et al., 2007).
Clemen et al. (2010) stated that the KIAA0196 gene contains 29 exons.
Using radiation hybrid analysis, Nagase et al. (1996) mapped the KIAA0196 gene to chromosome 8. By genomic sequence analysis, Porkka et al. (2004) mapped the KIAA0196 gene to chromosome 8q24.
Autosomal Dominant Spastic Paraplegia 8
Valdmanis et al. (2007) identified 3 mutations in the KIAA0196 gene in 6 families that showed linkage to the hereditary spastic paraplegia locus SPG8 (603563), on 8q24.13. One mutation, V626F (610657.0001), was shared by 4 different families of no known relatedness. An L619F mutation (610657.0002) was found in a Brazilian family. The third mutation, N471D (610657.0003), was identified in a smaller family of European origin and lies in a spectrin domain. Both the L619 and the V626 residues are strictly conserved across species and likely have a notable effect on the structure of the protein product strumpellin. Rescue studies with human mRNA injected in zebrafish treated with morpholino oligonucleotides to knock down the endogenous protein showed that mutations at these 2 residues impaired the normal function of the KIAA0196 gene.
In 10 affected members of a large Dutch family with SPG8, de Bot et al. (2013) identified a heterozygous missense mutation in the KIAA0196 gene (G696A; 610657.0005). The mutation was found by targeted sequencing of the KIAA0196 gene in 21 index patients with autosomal dominant SPG; 2 index patients carried the mutation and were later found to be related.
Ritscher-Schinzel Syndrome 1
In 11 patients with Ritscher-Schinzel syndrome-1 (RTSC1; 220210) from an isolated community in northern Manitoba, Canada, Elliott et al. (2013) identified a homozygous splice site mutation in the KIAA0196 gene (610657.0004). The mutation was found by homozygosity mapping followed by candidate gene sequencing, and segregated with the disorder in the families. Four of the patients had previously been reported by Marles et al. (1995). Analysis of patient cells showed an 8-fold decrease in KIAA0196 mRNA compared to controls, suggesting that the mutant transcript may be subject to nonsense-mediated mRNA decay. Western blot analysis showed that the protein was reduced by 60% compared to controls.
Clemen et al. (2010) demonstrated that knockdown of Kiaa0196 in zebrafish caused severe cardiac contractile dysfunction, tail curvature, and impaired motility. Impaired motility was due to a loss of central and peripheral motoneuron formation, suggesting a loss-of-function pathogenesis in SPG8.
In 4 apparently unrelated families of European ancestry, Valdmanis et al. (2007) found that a val626-to-phe (V626F) mutation in the KIAA0196 gene, arising from a heterozygous 1956G-T transversion in exon 15, segregated with spastic paraplegia (SPG8; 603563).
In a Brazilian family, Valdmanis et al. (2007) found that a leu619-to-phe (L619F) mutation, arising from a heterozygous 1937G-C transversion in exon 14 of the KIAA0196 gene, segregated with hereditary spastic paraplegia (SPG8; 603563).
In a small family of European origin, Valdmanis et al. (2007) found that hereditary spastic paraplegia (SPG8; 603563) segregated with an N471D mutation in the KIAA0196 gene. The amino acid substitution arose from a heterozygous 1491A-G transition in exon 11. In cellular studies, Clemen et al. (2010) found that the mutant N471D protein had normal subcellular localization and colocalization with VCP (601023). Expression of the N471D protein showed no effect on the velocity of wound healing compared to wildtype in an vitro-based assay.
In 11 First Nation patients from an isolated community in northern Manitoba, Canada, with Ritscher-Schinzel syndrome-1 (RTSC1; 220210), Elliott et al. (2013) identified homozygosity for 3 variants in intron 27 of the KIAA0196 gene: c.3335+2T-A, c.3335+4C-A, and c.3335+8A-G. The mutations were found by homozygosity mapping followed by candidate gene sequencing, and segregated with the disorder in the families. None of these variants was present in the dbSNP database or in 5 control individuals. Unaffected parents were heterozygous for the variants. Only the c.3335+2T-A variant was predicted to have a functional effect on splicing, causing the skipping of exon 27, a frameshift, and premature termination with the loss of 29 highly conserved amino acids. Analysis of patient cells showed an 8-fold decrease in KIAA0196 mRNA compared to controls, suggesting that the mutant transcript may be subject to nonsense-mediated mRNA decay. Western blot analysis showed that the protein was reduced by 60% compared to controls. The c.3335+8A-G variant created a restriction site that allowed for analysis of newborn blood spots from the same population. Fifteen of 133 samples were heterozygous for the mutation, indicating that 1 in 9 individuals from this region is a carrier of the disorder. This result predicted that 1 in 325 children in the next generation will have RTSC. Four of the patients had previously been reported by Marles et al. (1995).
In 10 affected members of a large Dutch family with spastic paraplegia (SPG8; 603563), de Bot et al. (2013) identified a heterozygous c.2087G-C transversion in exon 17 of the KIAA0196 gene, resulting in a gly696-to-ala (G696A) substitution at a highly conserved residue. The mutation was found by targeted sequencing of the KIAA0196 gene in 21 index patients with autosomal dominant SPG. It was not found in approximately 13,000 control chromosomes in the Exome Variant Server database. Functional studies were not performed. The patients had onset of a pure form of spastic paraplegia between ages 21 and 57 years.
Clemen, C. S., Tangavelou, K., Strucksberg, K.-H., Just, S., Gaertner, L., Regus-Leidig, H., Stumpf, M., Reimann, J., Coras, R., Morgan, R. O., Fernandez, M.-P., Hofmann, A., Muller, S., Schoser, B., Hanisch, F.-G., Rottbauer, W., Blumcke, I., von Horsten, S., Eichinger, L., Schroder, R. Strumpellin is a novel valosin-containing protein binding partner linking hereditary spastic paraplegia to protein aggregation diseases. Brain 133: 2920-2941, 2010. [PubMed: 20833645] [Full Text: https://doi.org/10.1093/brain/awq222]
de Bot, S. T., Vermeer, S., Buijsman, W., Heister, A., Voorendt, M., Verrips, A., Scheffer, H., Kremer, H. P. H., van de Warrenburg, B. P. C., Kamsteeg, E.-J. Pure adult-onset spastic paraplegia caused by a novel mutation in the KIAA0196 (SPG8) gene. J. Neurol. 260: 1765-1769, 2013. [PubMed: 23455931] [Full Text: https://doi.org/10.1007/s00415-013-6870-x]
Elliott, A. M., Simard, L. R., Coghlan, G., Chudley, A. E., Chodirker, B. N., Greenberg, C. R., Burch, T., Ly, V., Hatch, G. M., Zelinski, T. A novel mutation in KIAA0196: identification of a gene involved in Ritscher-Schinzel/3C syndrome in a First Nations cohort. J. Med. Genet. 50: 819-822, 2013. [PubMed: 24065355] [Full Text: https://doi.org/10.1136/jmedgenet-2013-101715]
Jia, D., Gomez, T. S., Metlagel, Z., Umetani, J., Otwinowski, Z., Rosen, M. K., Billadeau, D. D. WASH and WAVE actin regulators of the Wiskott-Aldrich syndrome protein (WASP) family are controlled by analogous structurally related complexes. Proc. Nat. Acad. Sci. 107: 10442-10447, 2010. [PubMed: 20498093] [Full Text: https://doi.org/10.1073/pnas.0913293107]
Marles, S. L., Chodirker, B. N., Greenberg, C. R., Chudley, A. E. Evidence for Ritscher-Schinzel syndrome in Canadian native Indians. Am. J. Med. Genet. 56: 343-350, 1995. [PubMed: 7604842] [Full Text: https://doi.org/10.1002/ajmg.1320560402]
Nagase, T., Seki, N., Ishikawa, K., Tanaka, A., Nomura, N. Prediction of the coding sequences of unidentified human genes. V. The coding sequences of 40 new genes (KIAA0161-KIAA0200) deduced by analysis of cDNA clones from human cell line KG-1. DNA Res. 3: 17-24, 1996. [PubMed: 8724849] [Full Text: https://doi.org/10.1093/dnares/3.1.17]
Porkka, K. P., Tammela, T. L. J., Vessella, R. L., Visakorpi, T. RAD21 and KIAA0196 at 8q24 are amplified and overexpressed in prostate cancer. Genes Chromosomes Cancer 39: 1-10, 2004. [PubMed: 14603436] [Full Text: https://doi.org/10.1002/gcc.10289]
Valdmanis, P. N., Meijer, I. A., Reynolds, A., Lei, A, MacLeod, P., Schlesinger, D., Zatz, M., Reid, E., Dion, P. A., Drapeau, P., Rouleau, G. A. Mutations in the KIAA0196 gene at the SPG8 locus cause hereditary spastic paraplegia. Am. J. Hum. Genet. 80: 152-161, 2007. [PubMed: 17160902] [Full Text: https://doi.org/10.1086/510782]