Plxna3 plexin A3 [Mus musculus (house mouse)] - Gene

Summary

Official Symbol: Plxna3provided by MGI
Official Full Name: plexin A3provided by MGI
Primary source: MGI:MGI:107683
See related: Ensembl:ENSMUSG00000031398 AllianceGenome:MGI:107683
Gene type: protein coding
RefSeq status: VALIDATED
Organism: Mus musculus
Lineage: Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Glires; Rodentia; Myomorpha; Muroidea; Muridae; Murinae; Mus; Mus
Also known as: SEX; Plxa3; Plxn3; Plxn4; PlexA3; mKIAA4078
Summary: Enables semaphorin receptor activity. Involved in nervous system development and positive regulation of cytoskeleton organization. Acts upstream of or within generation of neurons; hippocampus development; and negative chemotaxis. Predicted to be located in plasma membrane. Predicted to be integral component of membrane. Predicted to be part of semaphorin receptor complex. Predicted to be integral component of plasma membrane. Is expressed in several structures, including alimentary system; central nervous system; genitourinary system; integumental system; and sensory organ. Orthologous to human PLXNA3 (plexin A3). [provided by Alliance of Genome Resources, Apr 2022]
Expression: Broad expression in whole brain E14.5 (RPKM 44.1), CNS E14 (RPKM 39.8) and 15 other tissues See more
Orthologs: human all
NEW: Try the new Gene table
Try the new Transcript table

Genomic context

Location:: X A7.3; X 38.0 cM

Exon count:: 35

Annotation release	Status	Assembly	Chr	Location
RS_2024_02	current	GRCm39 (GCF_000001635.27)	X	NC_000086.8 (73372644..73388295)
108.20200622	previous assembly	GRCm38.p6 (GCF_000001635.26)	X	NC_000086.7 (74328290..74344689)

Chromosome X - NC_000086.8 Genomic Context describing neighboring genes

Genomic regions, transcripts, and products

Go to the top of the page Help

Go to reference sequence details

Genomic Sequence:

Go to nucleotide: Graphics FASTA GenBank

Expression

Go to the top of the page Help

See details

Project title: Mouse ENCODE transcriptome data
Description: RNA profiling data sets generated by the Mouse ENCODE project.
BioProject: PRJNA66167
Publication: PMID 25409824
Analysis date: n/a

Bibliography

Go to the top of the page Help

GeneRIFs: Gene References Into Functions

What's a GeneRIF?

PLXNA1 and PLXNA3 may have roles in inherited GnRH deficiency and cooperate to pattern the nasal axons that guide gonadotropin-releasing hormone neurons
Title: PLXNA1 and PLXNA3 cooperate to pattern the nasal axons that guide gonadotropin-releasing hormone neurons.
genetic findings demonstrate that Sema3a repellent signaling plays a role in the establishment of proper afferent projections in SAG neurons, and this signaling likely occurs through a receptor complex involving Npn1 and either plexinA1 or plexinA3
Title: Deletion of Sema3a or plexinA1/plexinA3 causes defects in sensory afferent projections of statoacoustic ganglion neurons.
the plexin A3 GAP domain adopts a closed conformation and cannot accommodate R-Ras/M-Ras in its substrate-binding site, providing a structural basis for the autoinhibited state of plexins
Title: Crystal structure of the plexin A3 intracellular region reveals an autoinhibited conformation through active site sequestration.
The combined loss of PLXNA3 and PLXNA4 impaired facial branchiomotor axon guidance more severely than loss of either plexin alone, suggesting that SEMA3A and SEMA3F signals, even though both essential, are partially redundant.
Title: Plexin A3 and plexin A4 convey semaphorin signals during facial nerve development.
the signaling of plexin-A3, plexin-A4, and Sema6A is at least partially required for dorsal turning of the corticospinal tract axons
Title: Dorsal turning of motor corticospinal axons at the pyramidal decussation requires plexin signaling.
These results indicate that the stereotyped pruning of the visual and motor CST axon collaterals is differentially regulated and that this specificity arises from the differential expression of plexin receptors in the cortex.
Title: Plexin signaling selectively regulates the stereotyped pruning of corticospinal axons from visual cortex.
plexin-A3 and plexin-A4 are expressed in newly-differentiated sympathetic neurons, but not their neural crest precursors. They function cooperatively to regulate the migration of sympathetic neurons and then differentially to guide the sympathetic axons.
Title: Plexin-A3 and plexin-A4 restrict the migration of sympathetic neurons but not their neural crest precursors.

Submit: New GeneRIF Correction

Variation

Go to the top of the page Help

Alleles

Alleles of this type are documented at Mouse Genome Informatics (MGI)

Targeted (3) 1 citation

Interactions

Go to the top of the page Help

Products	Interactant	Other Gene	Complex	Source	Pubs	Description

General gene information

Go to the top of the page Help

Markers

REN89674 (e-PCR)
- UniSTS:414472

NoName (e-PCR)
- UniSTS:487452

Son (e-PCR), detects polymorphism
- UniSTS:527563

NoName (e-PCR)
- UniSTS:238042

Gene Ontology Provided by MGI

Function	Evidence Code	Pubs
enables semaphorin receptor activity	IBA Inferred from Biological aspect of Ancestor more info
enables semaphorin receptor activity	IMP Inferred from Mutant Phenotype more info	PubMed

Process	Evidence Code	Pubs
acts_upstream_of axon extension involved in axon guidance	IGI Inferred from Genetic Interaction more info	PubMed
acts_upstream_of_or_within axon guidance	IMP Inferred from Mutant Phenotype more info	PubMed
involved_in branchiomotor neuron axon guidance	IMP Inferred from Mutant Phenotype more info	PubMed
involved_in facial nerve structural organization	IMP Inferred from Mutant Phenotype more info	PubMed
involved_in gonadotrophin-releasing hormone neuronal migration to the hypothalamus	IGI Inferred from Genetic Interaction more info	PubMed
acts_upstream_of_or_within hippocampus development	IMP Inferred from Mutant Phenotype more info	PubMed
acts_upstream_of_or_within negative chemotaxis	IGI Inferred from Genetic Interaction more info	PubMed
acts_upstream_of_or_within negative regulation of axon extension involved in axon guidance	IGI Inferred from Genetic Interaction more info	PubMed
involved_in negative regulation of cell adhesion	IBA Inferred from Biological aspect of Ancestor more info
acts_upstream_of_or_within neuron projection extension	IGI Inferred from Genetic Interaction more info	PubMed
acts_upstream_of_or_within neuron projection guidance	IMP Inferred from Mutant Phenotype more info	PubMed
involved_in olfactory nerve formation	IGI Inferred from Genetic Interaction more info	PubMed
involved_in positive regulation of axonogenesis	IBA Inferred from Biological aspect of Ancestor more info
involved_in positive regulation of cytoskeleton organization	IMP Inferred from Mutant Phenotype more info	PubMed
acts_upstream_of_or_within pyramidal neuron development	IMP Inferred from Mutant Phenotype more info	PubMed
involved_in regulation of GTPase activity	IBA Inferred from Biological aspect of Ancestor more info
involved_in regulation of cell migration	IBA Inferred from Biological aspect of Ancestor more info
involved_in regulation of cell shape	IBA Inferred from Biological aspect of Ancestor more info
involved_in semaphorin-plexin signaling pathway	IMP Inferred from Mutant Phenotype more info	PubMed
involved_in trigeminal nerve structural organization	IMP Inferred from Mutant Phenotype more info	PubMed

Component	Evidence Code	Pubs
located_in membrane	IEA Inferred from Electronic Annotation more info
is_active_in plasma membrane	IBA Inferred from Biological aspect of Ancestor more info
part_of semaphorin receptor complex	IBA Inferred from Biological aspect of Ancestor more info

General protein information

Go to the top of the page Help

Preferred Names: plexin-A3

Names: plexin 3

NCBI Reference Sequences (RefSeq)

Go to the top of the page Help

NEW Try the new Transcript table

RefSeqs maintained independently of Annotated Genomes

These reference sequences exist independently of genome builds. Explain

These reference sequences are curated independently of the genome annotation cycle, so their versions may not match the RefSeq versions in the current genome build. Identify version mismatches by comparing the version of the RefSeq in this section to the one reported in Genomic regions, transcripts, and products above.

mRNA and Protein(s)

NM_001358129.1 → NP_001345058.1 plexin-A3 isoform 2 precursor

Status: VALIDATED

Source sequence(s)

AL807376, BC093482, CJ192479

Conserved Domains (7) summary

cd11273
Location:22 → 490

Sema_plexin_A3; The Sema domain, a protein interacting module, of Plexin A3

smart00423
Location:789 → 830

PSI; domain found in Plexins, Semaphorins and Integrins

cd01179
Location:936 → 1022

IPT_plexin_repeat2; Second repeat of the IPT domain of Plexins and Cell Surface Receptors (PCSR) . Plexins are involved in the regulation of cell proliferation and of cellular adhesion and repulsion receptors. In general, there are three copies of the IPT domain present ...

cd01180
Location:841 → 935

IPT_plexin_repeat1; First repeat of the IPT domain of Plexins and Cell Surface Receptors (PCSR) . Plexins are involved in the regulation of cell proliferation and of cellular adhesion and repulsion receptors. In general, there are three copies of the IPT domain present ...

pfam01437
Location:491 → 531

PSI; Plexin repeat

pfam08337
Location:1217 → 1765

Plexin_cytopl; Plexin cytoplasmic RasGAP domain

cl15674
Location:1024 → 1111

IPT; Immunoglobulin-like fold, Plexins, Transcription factors (IPT). IPTs are also known as Transcription factor ImmunoGlobin (TIG) domains. They are present in intracellular transcription factors, cell surface receptors (such as plexins and scatter factor ...
NM_008883.2 → NP_032909.2 plexin-A3 isoform 1 precursor

See identical proteins and their annotated locations for NP_032909.2

Status: VALIDATED

Source sequence(s)

AL807376, CJ192479

Consensus CDS

CCDS30228.1

UniProtKB/Swiss-Prot

A5D6Q5, P70208, Q684J0, Q8BWZ5

UniProtKB/TrEMBL

A0A158SIT4

Related

ENSMUSP00000004326.4, ENSMUST00000004326.4

Conserved Domains (9) summary

cd11273
Location:22 → 490

Sema_plexin_A3; The Sema domain, a protein interacting module, of Plexin A3

cd00603
Location:1126 → 1209

IPT_PCSR; IPT domain of Plexins and Cell Surface Receptors (PCSR) and related proteins . This subgroup contains IPT domains of plexins, receptors, like the plasminogen-related growth factor receptors, the hepatocyte growth factor-scatter factors, and the ...

cd01179
Location:936 → 1022

IPT_plexin_repeat2; Second repeat of the IPT domain of Plexins and Cell Surface Receptors (PCSR) . Plexins are involved in the regulation of cell proliferation and of cellular adhesion and repulsion receptors. In general, there are three copies of the IPT domain present ...

cd01180
Location:841 → 935

IPT_plexin_repeat1; First repeat of the IPT domain of Plexins and Cell Surface Receptors (PCSR) . Plexins are involved in the regulation of cell proliferation and of cellular adhesion and repulsion receptors. In general, there are three copies of the IPT domain present ...

cd01181
Location:1024 → 1124

IPT_plexin_repeat3; Third repeat of the IPT domain of Plexins and Cell Surface Receptors (PCSR) . Plexins are involved in the regulation of cell proliferation and of cellular adhesion and repulsion receptors. In general, there are three copies of the IPT domain present ...

pfam01437
Location:491 → 528

PSI; Plexin repeat

pfam08337
Location:1294 → 1842

Plexin_cytopl; Plexin cytoplasmic RasGAP domain

pfam17960
Location:546 → 637

TIG_plexin; TIG domain

pfam18020
Location:691 → 785

TIG_2; TIG domain found in plexin

RefSeqs of Annotated Genomes: GCF_000001635.27-RS_2024_02

The following sections contain reference sequences that belong to a specific genome build. Explain

Reference GRCm39 C57BL/6J

Genomic

NC_000086.8 Reference GRCm39 C57BL/6J

Range

73372644..73388295

Download

GenBank, FASTA, Sequence Viewer (Graphics)

mRNA and Protein(s)

XM_030251258.2 → XP_030107118.1 plexin-A3 isoform X1

Conserved Domains (10) summary

smart00423
Location:339 → 377

PSI; domain found in Plexins, Semaphorins and Integrins

cd00603
Location:973 → 1056

IPT_PCSR; IPT domain of Plexins and Cell Surface Receptors (PCSR) and related proteins . This subgroup contains IPT domains of plexins, receptors, like the plasminogen-related growth factor receptors, the hepatocyte growth factor-scatter factors, and the ...

cd01179
Location:783 → 869

IPT_plexin_repeat2; Second repeat of the IPT domain of Plexins and Cell Surface Receptors (PCSR) . Plexins are involved in the regulation of cell proliferation and of cellular adhesion and repulsion receptors. In general, there are three copies of the IPT domain present ...

cd01180
Location:688 → 782

IPT_plexin_repeat1; First repeat of the IPT domain of Plexins and Cell Surface Receptors (PCSR) . Plexins are involved in the regulation of cell proliferation and of cellular adhesion and repulsion receptors. In general, there are three copies of the IPT domain present ...

cd01181
Location:871 → 971

IPT_plexin_repeat3; Third repeat of the IPT domain of Plexins and Cell Surface Receptors (PCSR) . Plexins are involved in the regulation of cell proliferation and of cellular adhesion and repulsion receptors. In general, there are three copies of the IPT domain present ...

pfam01437
Location:485 → 532

PSI; Plexin repeat

pfam08337
Location:1142 → 1688

Plexin_cytopl; Plexin cytoplasmic RasGAP domain

pfam17960
Location:394 → 484

TIG_plexin; TIG domain

pfam18020
Location:538 → 632

TIG_2; TIG domain found in plexin

cl15693
Location:47 → 337

Sema; The Sema domain, a protein interacting module, of semaphorins and plexins
XM_006527902.4 → XP_006527965.1 plexin-A3 isoform X2

Conserved Domains (10) summary

smart00423
Location:227 → 265

PSI; domain found in Plexins, Semaphorins and Integrins

cd00603
Location:861 → 944

IPT_PCSR; IPT domain of Plexins and Cell Surface Receptors (PCSR) and related proteins . This subgroup contains IPT domains of plexins, receptors, like the plasminogen-related growth factor receptors, the hepatocyte growth factor-scatter factors, and the ...

cd01179
Location:671 → 757

IPT_plexin_repeat2; Second repeat of the IPT domain of Plexins and Cell Surface Receptors (PCSR) . Plexins are involved in the regulation of cell proliferation and of cellular adhesion and repulsion receptors. In general, there are three copies of the IPT domain present ...

cd01180
Location:576 → 670

IPT_plexin_repeat1; First repeat of the IPT domain of Plexins and Cell Surface Receptors (PCSR) . Plexins are involved in the regulation of cell proliferation and of cellular adhesion and repulsion receptors. In general, there are three copies of the IPT domain present ...

cd01181
Location:759 → 859

IPT_plexin_repeat3; Third repeat of the IPT domain of Plexins and Cell Surface Receptors (PCSR) . Plexins are involved in the regulation of cell proliferation and of cellular adhesion and repulsion receptors. In general, there are three copies of the IPT domain present ...

pfam01437
Location:373 → 420

PSI; Plexin repeat

pfam08337
Location:1030 → 1576

Plexin_cytopl; Plexin cytoplasmic RasGAP domain

pfam17960
Location:282 → 372

TIG_plexin; TIG domain

pfam18020
Location:426 → 520

TIG_2; TIG domain found in plexin

cl15693
Location:1 → 225

Sema; The Sema domain, a protein interacting module, of semaphorins and plexins
XM_036161855.1 → XP_036017748.1 plexin-A3 isoform X4

Conserved Domains (7) summary

cd00603
Location:427 → 510

IPT_PCSR; IPT domain of Plexins and Cell Surface Receptors (PCSR) and related proteins . This subgroup contains IPT domains of plexins, receptors, like the plasminogen-related growth factor receptors, the hepatocyte growth factor-scatter factors, and the ...

cd01179
Location:237 → 323

IPT_plexin_repeat2; Second repeat of the IPT domain of Plexins and Cell Surface Receptors (PCSR) . Plexins are involved in the regulation of cell proliferation and of cellular adhesion and repulsion receptors. In general, there are three copies of the IPT domain present ...

cd01180
Location:142 → 236

IPT_plexin_repeat1; First repeat of the IPT domain of Plexins and Cell Surface Receptors (PCSR) . Plexins are involved in the regulation of cell proliferation and of cellular adhesion and repulsion receptors. In general, there are three copies of the IPT domain present ...

cd01181
Location:325 → 425

IPT_plexin_repeat3; Third repeat of the IPT domain of Plexins and Cell Surface Receptors (PCSR) . Plexins are involved in the regulation of cell proliferation and of cellular adhesion and repulsion receptors. In general, there are three copies of the IPT domain present ...

pfam01437
Location:90 → 139

PSI; Plexin repeat

pfam08337
Location:595 → 1143

Plexin_cytopl; Plexin cytoplasmic RasGAP domain

pfam18020
Location:2 → 86

TIG_2; TIG domain found in plexin
XM_030251259.1 → XP_030107119.1 plexin-A3 isoform X3

Conserved Domains (8) summary

cd00603
Location:564 → 647

IPT_PCSR; IPT domain of Plexins and Cell Surface Receptors (PCSR) and related proteins . This subgroup contains IPT domains of plexins, receptors, like the plasminogen-related growth factor receptors, the hepatocyte growth factor-scatter factors, and the ...

cd01179
Location:374 → 460

IPT_plexin_repeat2; Second repeat of the IPT domain of Plexins and Cell Surface Receptors (PCSR) . Plexins are involved in the regulation of cell proliferation and of cellular adhesion and repulsion receptors. In general, there are three copies of the IPT domain present ...

cd01180
Location:279 → 373

IPT_plexin_repeat1; First repeat of the IPT domain of Plexins and Cell Surface Receptors (PCSR) . Plexins are involved in the regulation of cell proliferation and of cellular adhesion and repulsion receptors. In general, there are three copies of the IPT domain present ...

cd01181
Location:462 → 562

IPT_plexin_repeat3; Third repeat of the IPT domain of Plexins and Cell Surface Receptors (PCSR) . Plexins are involved in the regulation of cell proliferation and of cellular adhesion and repulsion receptors. In general, there are three copies of the IPT domain present ...

pfam01437
Location:227 → 276

PSI; Plexin repeat

pfam08337
Location:732 → 1280

Plexin_cytopl; Plexin cytoplasmic RasGAP domain

pfam17960
Location:1 → 75

TIG_plexin; TIG domain

pfam18020
Location:129 → 223

TIG_2; TIG domain found in plexin
XM_030251260.2 → XP_030107120.1 plexin-A3 isoform X4

Conserved Domains (7) summary

cd00603
Location:427 → 510

IPT_PCSR; IPT domain of Plexins and Cell Surface Receptors (PCSR) and related proteins . This subgroup contains IPT domains of plexins, receptors, like the plasminogen-related growth factor receptors, the hepatocyte growth factor-scatter factors, and the ...

cd01179
Location:237 → 323

IPT_plexin_repeat2; Second repeat of the IPT domain of Plexins and Cell Surface Receptors (PCSR) . Plexins are involved in the regulation of cell proliferation and of cellular adhesion and repulsion receptors. In general, there are three copies of the IPT domain present ...

cd01180
Location:142 → 236

IPT_plexin_repeat1; First repeat of the IPT domain of Plexins and Cell Surface Receptors (PCSR) . Plexins are involved in the regulation of cell proliferation and of cellular adhesion and repulsion receptors. In general, there are three copies of the IPT domain present ...

cd01181
Location:325 → 425

IPT_plexin_repeat3; Third repeat of the IPT domain of Plexins and Cell Surface Receptors (PCSR) . Plexins are involved in the regulation of cell proliferation and of cellular adhesion and repulsion receptors. In general, there are three copies of the IPT domain present ...

pfam01437
Location:90 → 139

PSI; Plexin repeat

pfam08337
Location:595 → 1143

Plexin_cytopl; Plexin cytoplasmic RasGAP domain

pfam18020
Location:2 → 86

TIG_2; TIG domain found in plexin
XM_036161854.1 → XP_036017747.1 plexin-A3 isoform X3

Related

ENSMUST00000154062.8

Conserved Domains (8) summary

cd00603
Location:564 → 647

IPT_PCSR; IPT domain of Plexins and Cell Surface Receptors (PCSR) and related proteins . This subgroup contains IPT domains of plexins, receptors, like the plasminogen-related growth factor receptors, the hepatocyte growth factor-scatter factors, and the ...

cd01179
Location:374 → 460

IPT_plexin_repeat2; Second repeat of the IPT domain of Plexins and Cell Surface Receptors (PCSR) . Plexins are involved in the regulation of cell proliferation and of cellular adhesion and repulsion receptors. In general, there are three copies of the IPT domain present ...

cd01180
Location:279 → 373

IPT_plexin_repeat1; First repeat of the IPT domain of Plexins and Cell Surface Receptors (PCSR) . Plexins are involved in the regulation of cell proliferation and of cellular adhesion and repulsion receptors. In general, there are three copies of the IPT domain present ...

cd01181
Location:462 → 562

IPT_plexin_repeat3; Third repeat of the IPT domain of Plexins and Cell Surface Receptors (PCSR) . Plexins are involved in the regulation of cell proliferation and of cellular adhesion and repulsion receptors. In general, there are three copies of the IPT domain present ...

pfam01437
Location:227 → 276

PSI; Plexin repeat

pfam08337
Location:732 → 1280

Plexin_cytopl; Plexin cytoplasmic RasGAP domain

pfam17960
Location:1 → 75

TIG_plexin; TIG domain

pfam18020
Location:129 → 223

TIG_2; TIG domain found in plexin
XM_030251261.1 → XP_030107121.1 plexin-A3 isoform X5

Conserved Domains (5) summary

cd00603
Location:298 → 381

IPT_PCSR; IPT domain of Plexins and Cell Surface Receptors (PCSR) and related proteins . This subgroup contains IPT domains of plexins, receptors, like the plasminogen-related growth factor receptors, the hepatocyte growth factor-scatter factors, and the ...

cd01179
Location:108 → 194

IPT_plexin_repeat2; Second repeat of the IPT domain of Plexins and Cell Surface Receptors (PCSR) . Plexins are involved in the regulation of cell proliferation and of cellular adhesion and repulsion receptors. In general, there are three copies of the IPT domain present ...

cd01180
Location:13 → 107

IPT_plexin_repeat1; First repeat of the IPT domain of Plexins and Cell Surface Receptors (PCSR) . Plexins are involved in the regulation of cell proliferation and of cellular adhesion and repulsion receptors. In general, there are three copies of the IPT domain present ...

cd01181
Location:196 → 296

IPT_plexin_repeat3; Third repeat of the IPT domain of Plexins and Cell Surface Receptors (PCSR) . Plexins are involved in the regulation of cell proliferation and of cellular adhesion and repulsion receptors. In general, there are three copies of the IPT domain present ...

pfam08337
Location:467 → 1013

Plexin_cytopl; Plexin cytoplasmic RasGAP domain
XM_006527903.4 → XP_006527966.1 plexin-A3 isoform X3

Conserved Domains (8) summary

cd00603
Location:564 → 647

IPT_PCSR; IPT domain of Plexins and Cell Surface Receptors (PCSR) and related proteins . This subgroup contains IPT domains of plexins, receptors, like the plasminogen-related growth factor receptors, the hepatocyte growth factor-scatter factors, and the ...

cd01179
Location:374 → 460

IPT_plexin_repeat2; Second repeat of the IPT domain of Plexins and Cell Surface Receptors (PCSR) . Plexins are involved in the regulation of cell proliferation and of cellular adhesion and repulsion receptors. In general, there are three copies of the IPT domain present ...

cd01180
Location:279 → 373

IPT_plexin_repeat1; First repeat of the IPT domain of Plexins and Cell Surface Receptors (PCSR) . Plexins are involved in the regulation of cell proliferation and of cellular adhesion and repulsion receptors. In general, there are three copies of the IPT domain present ...

cd01181
Location:462 → 562

IPT_plexin_repeat3; Third repeat of the IPT domain of Plexins and Cell Surface Receptors (PCSR) . Plexins are involved in the regulation of cell proliferation and of cellular adhesion and repulsion receptors. In general, there are three copies of the IPT domain present ...

pfam01437
Location:227 → 276

PSI; Plexin repeat

pfam08337
Location:732 → 1280

Plexin_cytopl; Plexin cytoplasmic RasGAP domain

pfam17960
Location:1 → 75

TIG_plexin; TIG domain

pfam18020
Location:129 → 223

TIG_2; TIG domain found in plexin