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

    Gene ID: 2703, updated on 28-Oct-2024

    Summary

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    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

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    See GJA8 in Genome Data Viewer
    Location:
    1q21.2
    Exon count:
    3
    Annotation release Status Assembly Chr Location
    RS_2024_08 current GRCh38.p14 (GCF_000001405.40) 1 NC_000001.11 (147902795..147914486)
    RS_2024_08 current T2T-CHM13v2.0 (GCF_009914755.1) 1 NC_060925.1 (146892371..146904865, complement)
    RS_2024_09 previous assembly GRCh37.p13 (GCF_000001405.25) 1 NC_000001.10 (147374921..147381396)

    Chromosome 1 - NC_000001.11Genomic Context describing neighboring genes Neighboring gene uncharacterized LOC102723321 Neighboring gene Sharpr-MPRA regulatory region 3144 Neighboring gene gap junction protein alpha 5 Neighboring gene OCT4-NANOG-H3K27ac-H3K4me1 hESC enhancer GRCh37_chr1:147305372-147305981 Neighboring gene OCT4-NANOG-H3K27ac-H3K4me1 hESC enhancer GRCh37_chr1:147305982-147306592 Neighboring gene OCT4-NANOG-H3K27ac-H3K4me1 hESC enhancer GRCh37_chr1:147309262-147309858 Neighboring gene PRAME family member 17 pseudogene Neighboring gene uncharacterized LOC105371229 Neighboring gene NANOG-H3K27ac hESC enhancer GRCh37_chr1:147420827-147421344 Neighboring gene G protein-coupled receptor 89B Neighboring gene PDZ domain containing 1 pseudogene 1 Neighboring gene tRNA-Arg (anticodon CCT) 6-2

    Genomic regions, transcripts, and products

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    Go to nucleotide: Graphics FASTA GenBank

    Expression

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    • Project title: HPA RNA-seq normal tissues 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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    Related articles in PubMed

    1. Identification and functional analysis of GJA8 mutation in a Chinese family with autosomal dominant perinuclear cataracts. Su D, et al. PLoS One, 2013. PMID 23555834, Free PMC Article
    2. A mutation in GJA8 (p.P88Q) is associated with "balloon-like" cataract with Y-sutural opacities in a family of Indian origin. Vanita V, et al. Mol Vis, 2008 Jun 17. PMID 18587493, Free PMC Article
    3. A mutant connexin50 with enhanced hemichannel function leads to cell death. Minogue PJ, et al. Invest Ophthalmol Vis Sci, 2009 Dec. PMID 19684000, Free PMC Article
    4. A novel GJA8 mutation (p.I31T) causing autosomal dominant congenital cataract in a Chinese family. Wang K, et al. Mol Vis, 2009 Dec 16. PMID 20019893, Free PMC Article
    5. Association between gap junction protein-alpha 8 polymorphisms and age-related cataract. Liu Y, et al. Mol Biol Rep, 2011 Feb. PMID 20582632

    See all (95) citations in PubMed

    GeneRIFs: Gene References Into Functions

    What's a GeneRIF?
    1. Association of variants in GJA8 with familial acorea-microphthalmia-cataract syndrome.
      Title: Association of variants in GJA8 with familial acorea-microphthalmia-cataract syndrome.
    2. 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.
    3. 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.
    4. 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.
    5. 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.
    6. 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.
    7. 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.
    8. 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.
    9. 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.
    10. 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
    		not available
    Chromosome 1q21.1 deletion syndrome
    MedGen: C2675897 OMIM: 612474 GeneReviews: 1q21.1 Recurrent Microdeletion
    		not available

    Variation

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    See variants in ClinVar

    See studies and variants in dbVar

    See Variation Viewer (GRCh37.p13)

    See Variation Viewer (GRCh38)

    Genotypes

    Pathways from PubChem

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    Interactions

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    Products Interactant Other Gene Complex Source Pubs Description

    General gene information

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    Markers

    Homology

    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

    1. NG_016242.2 RefSeqGene

      Range
      5002..11476
      Download
      GenBank, FASTA, Sequence Viewer (Graphics)

    mRNA and Protein(s)

    1. 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_2024_08

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

    Reference GRCh38.p14 Primary Assembly

    Genomic

    1. NC_000001.11 Reference GRCh38.p14 Primary Assembly

      Range
      147902795..147914486
      Download
      GenBank, FASTA, Sequence Viewer (Graphics)

    mRNA and Protein(s)

    1. 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

    Alternate T2T-CHM13v2.0

    Genomic

    1. NC_060925.1 Alternate T2T-CHM13v2.0

      Range
      146892371..146904865 complement
      Download
      GenBank, FASTA, Sequence Viewer (Graphics)

    mRNA and Protein(s)

    1. XM_054336002.1 → XP_054191977.1  gap junction alpha-8 protein isoform X1

    Nucleotide Protein
    Heading Accession and Version
    Protein Accession Links
    GenPept Link UniProtKB Link
    P48165.3 GenPept UniProtKB/Swiss-Prot:P48165

    Gene LinkOut

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