GJA8 gap junction protein alpha 8 [Homo sapiens (human)] - Gene

Summary

Official Symbol: GJA8provided by HGNC
Official Full Name: gap junction protein alpha 8provided by HGNC
Primary source: HGNC:HGNC:4281
See related: Ensembl:ENSG00000121634 MIM:600897; AllianceGenome:HGNC:4281
Gene type: protein coding
RefSeq status: REVIEWED
Organism: Homo sapiens
Lineage: Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae; Homo
Also known as: CAE; CAE1; CX50; CZP1; MP70; CTRCT1
Summary: This gene encodes a transmembrane connexin protein that is necessary for lens growth and maturation of lens fiber cells. The encoded protein is a component of gap junction channels and functions in a calcium and pH-dependent manner. Mutations in this gene have been associated with zonular pulverulent cataracts, nuclear progressive cataracts, and cataract-microcornea syndrome. [provided by RefSeq, Dec 2009]
Expression: Restricted expression toward testis (RPKM 2.4) See more
Orthologs: mouse all
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Genomic context

Location:: 1q21.2

Exon count:: 3

Annotation release	Status	Assembly	Chr	Location
RS_2023_10	current	GRCh38.p14 (GCF_000001405.40)	1	NC_000001.11 (147902795..147914486)
RS_2023_10	current	T2T-CHM13v2.0 (GCF_009914755.1)	1	NC_060925.1 (146892371..146904865, complement)
105.20220307	previous assembly	GRCh37.p13 (GCF_000001405.25)	1	NC_000001.10 (147374921..147381396)

Chromosome 1 - NC_000001.11 Genomic Context describing neighboring genes

Genomic regions, transcripts, and products

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Genomic Sequence:

Go to nucleotide: Graphics FASTA GenBank

Expression

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See details

Project title: HPA RNA-seq normal tissues
Description: RNA-seq was performed of tissue samples from 95 human individuals representing 27 different tissues in order to determine tissue-specificity of all protein-coding genes
BioProject: PRJEB4337
Publication: PMID 24309898
Analysis date: Wed Apr 4 07:08:55 2018

Bibliography

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GeneRIFs: Gene References Into Functions

What's a GeneRIF?

Association of variants in GJA8 with familial acorea-microphthalmia-cataract syndrome.
Title: Association of variants in GJA8 with familial acorea-microphthalmia-cataract syndrome.
Human Cx50 Isoleucine177 prevents heterotypic docking and formation of functional gap junction channels with Cx43.
Title: Human Cx50 Isoleucine177 prevents heterotypic docking and formation of functional gap junction channels with Cx43.
Novel compound heterozygous variant of GJA8 gene in two siblings with congenital cataract mimics an autosomal recessive trait.
Title: Novel compound heterozygous variant of GJA8 gene in two siblings with congenital cataract mimics an autosomal recessive trait.
Identification and functional analysis of two GJA8 variants in Chinese families with eye anomalies.
Title: Identification and functional analysis of two GJA8 variants in Chinese families with eye anomalies.
Identification of novel cis-mutations in the GJA8 gene in a 3-generation Iranian family with autosomal dominant congenital nuclear cataract.
Title: Identification of novel cis-mutations in the GJA8 gene in a 3-generation Iranian family with autosomal dominant congenital nuclear cataract.
Cataract-linked serine mutations in the gap junction protein connexin50 expose a sorting signal that promotes its lysosomal degradation.
Title: Cataract-linked serine mutations in the gap junction protein connexin50 expose a sorting signal that promotes its lysosomal degradation.
Molecular mechanisms underlying enhanced hemichannel function of a cataract-associated Cx50 mutant.
Title: Molecular mechanisms underlying enhanced hemichannel function of a cataract-associated Cx50 mutant.
Identification and functional analysis of a novel missense mutation in GJA8, p.Ala69Thr.
Title: Identification and functional analysis of a novel missense mutation in GJA8, p.Ala69Thr.
Aging-dependent loss of GAP junction proteins Cx46 and Cx50 in the fiber cells of human and mouse lenses accounts for the diminished coupling conductance.
Title: Aging-dependent loss of GAP junction proteins Cx46 and Cx50 in the fiber cells of human and mouse lenses accounts for the diminished coupling conductance.
Whole Exome Sequencing Reveals Novel and Recurrent Disease-Causing Variants in Lens Specific Gap Junctional Protein Encoding Genes Causing Congenital Cataract.
Title: Whole Exome Sequencing Reveals Novel and Recurrent Disease-Causing Variants in Lens Specific Gap Junctional Protein Encoding Genes Causing Congenital Cataract.

Submit: New GeneRIF Correction See all GeneRIFs (74)

Phenotypes

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Find tests for this gene in the NIH Genetic Testing Registry (GTR)

Review eQTL and phenotype association data in this region using PheGenI

Associated conditions

Description	Tests
Cataract 1 multiple types MedGen: C1861828 OMIM: 116200 GeneReviews: Not available	Compare labs
Chromosome 1q21.1 deletion syndrome MedGen: C2675897 OMIM: 612474 GeneReviews: 1q21.1 Recurrent Microdeletion	Compare labs

Copy number response

Description
Copy number response Triplosensitivity No evidence available (Last evaluated 2012-02-23) ClinGen Genome Curation Page Haploinsufficency Little evidence for dosage pathogenicity (Last evaluated 2012-02-23) ClinGen Genome Curation PagePubMed

Variation

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See variants in ClinVar

See studies and variants in dbVar

See Variation Viewer (GRCh37.p13)

See Variation Viewer (GRCh38)

Interactions

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Products	Interactant	Other Gene	Complex	Source	Pubs	Description

General gene information

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Markers

NoName (e-PCR)
- UniSTS:489787

NoName (e-PCR)
- UniSTS:480892

GJA8 (e-PCR)
- UniSTS:266367

PMC197251P4 (e-PCR)
- UniSTS:271853

Gene Ontology Provided by GOA

Function	Evidence Code	Pubs
enables gap junction channel activity	IBA Inferred from Biological aspect of Ancestor more info
enables gap junction channel activity	IDA Inferred from Direct Assay more info	PubMed
enables identical protein binding	IEA Inferred from Electronic Annotation more info
enables protein binding	IPI Inferred from Physical Interaction more info	PubMed

Process	Evidence Code	Pubs
involved_in cell-cell signaling	IBA Inferred from Biological aspect of Ancestor more info
involved_in gap junction-mediated intercellular transport	IBA Inferred from Biological aspect of Ancestor more info
involved_in gap junction-mediated intercellular transport	IDA Inferred from Direct Assay more info	PubMed
involved_in lens development in camera-type eye	IEA Inferred from Electronic Annotation more info
involved_in regulation of granulocyte macrophage colony-stimulating factor production	IEA Inferred from Electronic Annotation more info
involved_in transmembrane transport	IEA Inferred from Electronic Annotation more info

Component	Evidence Code	Pubs
part_of connexin complex	IBA Inferred from Biological aspect of Ancestor more info
part_of connexin complex	IDA Inferred from Direct Assay more info	PubMed
located_in plasma membrane	IDA Inferred from Direct Assay more info	PubMed

General protein information

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Preferred Names: gap junction alpha-8 protein

Names: cell surface glycoprotein; connexin 50; gap junction alpha 8; gap junction membrane channel protein alpha-8; gap junction protein alpha 8 50kDa; lens fiber protein MP70; lens intrinsic membrane protein MP70

NCBI Reference Sequences (RefSeq)

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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.

Genomic

NG_016242.2 RefSeqGene

Range

5002..11476

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GenBank, FASTA, Sequence Viewer (Graphics)

mRNA and Protein(s)

NM_005267.5 → NP_005258.2 gap junction alpha-8 protein

See identical proteins and their annotated locations for NP_005258.2

Status: REVIEWED

Source sequence(s)

AC239801, BQ184886, CD674975, DB476698

Consensus CDS

CCDS30834.1

UniProtKB/Swiss-Prot

A7L5M5, P48165, Q5VVN9, Q9NP25

UniProtKB/TrEMBL

A0A097IWA5, X5D7G1

Related

ENSP00000358238.1, ENST00000369235.2

Conserved Domains (4) summary

pfam00029
Location:3 → 229

Connexin

pfam03509
Location:260 → 325

Connexin50; Gap junction alpha-8 protein (Cx50)

pfam15623
Location:326 → 391

CT47; Cancer/testis gene family 47

pfam16791
Location:401 → 433

Connexin40_C; Connexin 40 C-terminal domain

RefSeqs of Annotated Genomes: GCF_000001405.40-RS_2023_10

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

Reference GRCh38.p14 Primary Assembly

Genomic

NC_000001.11 Reference GRCh38.p14 Primary Assembly

Range

147902795..147914486

Download

GenBank, FASTA, Sequence Viewer (Graphics)

mRNA and Protein(s)

XM_011509417.3 → XP_011507719.1 gap junction alpha-8 protein isoform X1

UniProtKB/TrEMBL

A0A097IWA5

Conserved Domains (5) summary

smart00037
Location:44 → 76

CNX; Connexin homologues

smart01089
Location:161 → 227

Connexin_CCC; Gap junction channel protein cysteine-rich domain

pfam00029
Location:3 → 228

Connexin; Connexin

pfam03509
Location:260 → 325

Connexin50; Gap junction alpha-8 protein (Cx50)

cl22451
Location:334 → 385

ASF1_hist_chap; ASF1 like histone chaperone