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Aliases for GJA8 Gene

Aliases for GJA8 Gene

  • Gap Junction Protein Alpha 8 2 3 5
  • Lens Fiber Protein MP70 3 4
  • Connexin 50 2 3
  • Gap Junction Protein, Alpha 8, 50kDa (Connexin 50) 2
  • Gap Junction Protein, Alpha 8, 50kD (Connexin 50) 2
  • Gap Junction Membrane Channel Protein Alpha-8 3
  • Lens Intrinsic Membrane Protein MP70 3
  • Gap Junction Protein, Alpha 8, 50kDa 2
  • Gap Junction Protein Alpha 8 50kDa 3
  • Gap Junction Alpha-8 Protein 3
  • Cell Surface Glycoprotein 3
  • Gap Junction Alpha 8 3
  • Connexin-50 4
  • CTRCT1 3
  • CX50 3
  • MP70 3
  • CAE1 3
  • CZP1 3
  • Cx50 4
  • CAE 3

External Ids for GJA8 Gene

Previous HGNC Symbols for GJA8 Gene

  • CAE1
  • CZP1
  • CAE

Previous GeneCards Identifiers for GJA8 Gene

  • GC01P145594
  • GC01P144100
  • GC01P144718
  • GC01P144882
  • GC01P144599
  • GC01P145841
  • GC01P147374
  • GC01P120788

Summaries for GJA8 Gene

Entrez Gene Summary for GJA8 Gene

  • 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]

GeneCards Summary for GJA8 Gene

GJA8 (Gap Junction Protein Alpha 8) is a Protein Coding gene. Diseases associated with GJA8 include Cataract 1, Multiple Types and Cataract Microcornea Syndrome. Among its related pathways are Development Slit-Robo signaling and Vesicle-mediated transport. Gene Ontology (GO) annotations related to this gene include channel activity and gap junction channel activity. An important paralog of this gene is GJA3.

UniProtKB/Swiss-Prot for GJA8 Gene

  • One gap junction consists of a cluster of closely packed pairs of transmembrane channels, the connexons, through which materials of low MW diffuse from one cell to a neighboring cell.

Tocris Summary for GJA8 Gene

  • Gap channels (gap junctions) are specialized cell-cell contacts that provide direct intracellular communication. They allow passive diffusion of molecules up to 1 kDa, including nutrients, metabolites (glucose), ions (K+, Ca2+) and second messengers (IP3, cAMP).

Gene Wiki entry for GJA8 Gene

Additional gene information for GJA8 Gene

No data available for CIViC summary , PharmGKB "VIP" Summary , fRNAdb sequence ontologies and piRNA Summary for GJA8 Gene

Genomics for GJA8 Gene

GeneHancer (GH) Regulatory Elements for GJA8 Gene

Promoters and enhancers for GJA8 Gene
GeneHancer (GH) Identifier GH Type GH
GH Sources Gene Association Score Total Score TSS distance (kb) Number of Genes Away Size (kb) Transcription Factor
Binding Sites
Gene Targets
GH01J147927 Promoter/Enhancer 2 EPDnew Ensembl ENCODE 11.3 +26.9 26922 3.9 HDGF PKNOX1 SIN3A ZNF2 ZBTB7B POLR2B FOS SP3 NFYC REST LOC105371229 GPR89B GJA8 NBPF14 PIR60446
GH01J148842 Promoter/Enhancer 2.2 EPDnew Ensembl ENCODE dbSUPER 9.8 +941.6 941600 3.5 HDGF ARID4B SIN3A ZNF2 YY1 ZNF207 ZNF263 SP3 ZHX2 MXD4 PDE4DIP LOC647481 GPR89B LOC100505824 ENSG00000228626 ENSG00000235988 HIST2H2BD GJA8 RN7SKP88 GC01M148879
GH01J147538 Promoter/Enhancer 2.1 EPDnew Ensembl ENCODE 9.9 -361.8 -361810 5.8 PKNOX1 FOXA2 ARNT NEUROD1 SIN3A FEZF1 ZNF2 YY1 ZNF213 ZNF416 BCL9 LOC647481 GPR89B LOC101927468 ACP6 OR13Z3P OR13Z2P OR13Z1P LOC100130018 ENSG00000235988
GH01J147699 Enhancer 0.9 Ensembl ENCODE 10.3 -202.5 -202530 1.4 CTCF PKNOX1 KLF1 NFIB SIN3A RAD21 RFX5 YY1 ELK1 ZNF143 LOC102723321 ACP6 ENSG00000234190 GJA5 GJA8 ENSG00000234225 ENSG00000227139 LOC105371230
GH01J147748 Enhancer 0.9 VISTA dbSUPER 10.1 -151.6 -151646 5.2 JUND ZNF512B HLF SCRT2 FOS GJA5 ENSG00000234190 GJA8 ACP6 PDIA3P1 ENSG00000274415 LOC105371230 LOC102723321
- Elite GeneHancer and/or Elite GeneHancer-gene association Download GeneHancer data from 2017 publication | Request up-to-date GeneHancer data (full dataset)

GeneHancers around GJA8 on UCSC Golden Path with GeneCards custom track

Top Transcription factor binding sites by QIAGEN in the GJA8 gene promoter:
  • Pax-4a
  • RREB-1
  • ER-alpha
  • PPAR-gamma2
  • PPAR-gamma1
  • Max1
  • USF1
  • USF-1
  • Max
  • c-Myc

Genomic Locations for GJA8 Gene

Genomic Locations for GJA8 Gene
12,468 bases
Plus strand
6,451 bases
Plus strand

Genomic View for GJA8 Gene

Genes around GJA8 on UCSC Golden Path with GeneCards custom track

Cytogenetic band:
GJA8 Gene in genomic location: bands according to Ensembl, locations according to GeneLoc (and/or Entrez Gene and/or Ensembl if different)
Genomic Location for GJA8 Gene
GeneLoc Logo Genomic Neighborhood Exon StructureGene Density

RefSeq DNA sequence for GJA8 Gene

Proteins for GJA8 Gene

  • Protein details for GJA8 Gene (UniProtKB/Swiss-Prot)

    Protein Symbol:
    Recommended name:
    Gap junction alpha-8 protein
    Protein Accession:
    Secondary Accessions:
    • A7L5M5
    • Q5VVN9
    • Q9NP25

    Protein attributes for GJA8 Gene

    433 amino acids
    Molecular mass:
    48229 Da
    Quaternary structure:
    • A connexon is composed of a hexamer of connexins. This particular connexin only forms junctional channels.

neXtProt entry for GJA8 Gene

Post-translational modifications for GJA8 Gene

  • Modification sites at PhosphoSitePlus
  • Modification sites at neXtProt

Other Protein References for GJA8 Gene

ENSEMBL proteins:
REFSEQ proteins:

No data available for DME Specific Peptides for GJA8 Gene

Domains & Families for GJA8 Gene

Gene Families for GJA8 Gene

Human Protein Atlas (HPA):
  • Disease related genes
  • Potential drug targets
  • Predicted membrane proteins
  • Transporters

Suggested Antigen Peptide Sequences for GJA8 Gene

GenScript: Design optimal peptide antigens:

Graphical View of Domain Structure for InterPro Entry



  • Belongs to the connexin family. Alpha-type (group II) subfamily.
  • Belongs to the connexin family. Alpha-type (group II) subfamily.
genes like me logo Genes that share domains with GJA8: view

Function for GJA8 Gene

Molecular function for GJA8 Gene

UniProtKB/Swiss-Prot Function:
One gap junction consists of a cluster of closely packed pairs of transmembrane channels, the connexons, through which materials of low MW diffuse from one cell to a neighboring cell.
GENATLAS Biochemistry:
gap junction protein alpha 8,50kDa,connexin 50 (MP70),expressed in lens,monomer of the connexon (six subunits including GJA3,GJA8,GJB1,GJB2)

Gene Ontology (GO) - Molecular Function for GJA8 Gene

GO ID Qualified GO term Evidence PubMed IDs
GO:0005243 gap junction channel activity IEA --
GO:0015267 channel activity TAS 7796604
genes like me logo Genes that share ontologies with GJA8: view
genes like me logo Genes that share phenotypes with GJA8: view

Human Phenotype Ontology for GJA8 Gene

HPO Id HPO Name Alternative Ids Definition Synonyms

Animal Models for GJA8 Gene

MGI Knock Outs for GJA8:
  • Gja8 Gja8<tm1b(EUCOMM)Hmgu>
  • Gja8 Gja8<tm1Rtm>
  • Gja8 Gja8<tm1Paul>
  • Gja8 Gja8<tm1Scr>

Animal Model Products

CRISPR Products

miRNA for GJA8 Gene

miRTarBase miRNAs that target GJA8

Inhibitory RNA Products

  • Search GeneCopoeia for shRNA, lentivirus and/or AAV clone products for GJA8

No data available for Enzyme Numbers (IUBMB) , Phenotypes From GWAS Catalog , Transcription Factor Targets and HOMER Transcription for GJA8 Gene

Localization for GJA8 Gene

Subcellular locations from UniProtKB/Swiss-Prot for GJA8 Gene

Cell membrane; Multi-pass membrane protein. Cell junction, gap junction.

Subcellular locations from

Extracellular space Cytosol Plasma membrane Cytoskeleton Lysosome Endosome Peroxisome ER Golgi Apparatus Nucleus Mitochondrion 0 1 2 3 4 5 Confidence
COMPARTMENTS Subcellular localization image for GJA8 gene
Compartment Confidence
plasma membrane 5
nucleus 2
extracellular 1
cytoskeleton 1
endoplasmic reticulum 1
cytosol 1

Gene Ontology (GO) - Cellular Components for GJA8 Gene

GO ID Qualified GO term Evidence PubMed IDs
GO:0005886 plasma membrane IEA --
GO:0005887 integral component of plasma membrane TAS 7796604
GO:0005921 gap junction IEA --
GO:0005922 connexin complex TAS,IEA --
GO:0016020 membrane IEA --
genes like me logo Genes that share ontologies with GJA8: view

No data available for Subcellular locations from the Human Protein Atlas (HPA) for GJA8 Gene

Pathways & Interactions for GJA8 Gene

genes like me logo Genes that share pathways with GJA8: view

Pathways by source for GJA8 Gene

1 GeneGo (Thomson Reuters) pathway for GJA8 Gene
1 Qiagen pathway for GJA8 Gene

Interacting Proteins for GJA8 Gene

Gene Ontology (GO) - Biological Process for GJA8 Gene

GO ID Qualified GO term Evidence PubMed IDs
GO:0002088 lens development in camera-type eye IEA --
GO:0007154 cell communication IEA --
GO:0007267 cell-cell signaling IEA --
GO:0007601 visual perception TAS 9497259
GO:0043010 camera-type eye development IEA --
genes like me logo Genes that share ontologies with GJA8: view

No data available for SIGNOR curated interactions for GJA8 Gene

Drugs & Compounds for GJA8 Gene

(12) Drugs for GJA8 Gene - From: DGIdb, IUPHAR, Tocris, and Novoseek

Name Status Disease Links Group Role Mechanism of Action Clinical Trials
Carbenoxolone Experimental Pharma Inhibitor 0
Flufenamic Acid Experimental Pharma Channel blocker, Inhibitor, Pore Blocker, Antagonist Calcium-activated chloride channel blocker; NSAID. Also activates TRPC6 1
octanol Investigational Pharma Inhibitor 0
Ca<sup>2+</sup> Pharma Activator, Full agonist, Agonist, Inhibitor, Antagonist, Channel blocker 0
10Panx Pharma Panx-1 mimetic inhibitor, Panx-1 mimetic inhibitory peptide; blocks pannexin-1 gap junctions 0

(1) Additional Compounds for GJA8 Gene - From: Novoseek

Name Synonyms Role CAS Number PubChem IDs PubMed IDs

(5) Tocris Compounds for GJA8 Gene

Compound Action Cas Number
10Panx Panx-1 mimetic inhibitory peptide; blocks pannexin-1 gap junctions 955091-53-9
Carbenoxolone disodium Gap junction blocker. Also inhibitor of 11 beta-hydroxysteroid dehydrogenase 7421-40-1
Gap 26 Gap junction blocker; inhibits smooth muscle contraction and IP3-mediated ATP release 197250-15-0
Gap 27 Selective gap junction blocker 198284-64-9
Scrambled 10Panx Scrambled version of 10Panx (Cat. No. 3348), Panx-1 mimetic inhibitory peptide 1315378-72-3
genes like me logo Genes that share compounds with GJA8: view

Transcripts for GJA8 Gene

mRNA/cDNA for GJA8 Gene

(2) REFSEQ mRNAs :
(0) Additional mRNA sequences :
(7) Selected AceView cDNA sequences:
(1) Ensembl transcripts including schematic representations, and UCSC links where relevant :

Unigene Clusters for GJA8 Gene

Gap junction protein, alpha 8, 50kDa:
Representative Sequences:

CRISPR Products

Inhibitory RNA Products

  • Search GeneCopoeia for shRNA, lentivirus and/or AAV clone products for GJA8

Alternative Splicing Database (ASD) splice patterns (SP) for GJA8 Gene

No ASD Table

Relevant External Links for GJA8 Gene

GeneLoc Exon Structure for
ECgene alternative splicing isoforms for

Expression for GJA8 Gene

mRNA expression in normal human tissues from GTEx, Illumina, BioGPS, and CGAP SAGE for GJA8 Gene

mRNA differential expression in normal tissues according to GTEx for GJA8 Gene

This gene is overexpressed in Testis (x51.1).

Protein differential expression in normal tissues from HIPED for GJA8 Gene

This gene is overexpressed in Pancreas (42.9), Fetal ovary (15.3), and Blymphocyte (10.8).

Integrated Proteomics: protein expression in normal tissues and cell lines from ProteomicsDB and MOPED for GJA8 Gene

Protein tissue co-expression partners for GJA8 Gene

NURSA nuclear receptor signaling pathways regulating expression of GJA8 Gene:


SOURCE GeneReport for Unigene cluster for GJA8 Gene:


mRNA Expression by UniProt/SwissProt for GJA8 Gene:

Tissue specificity: Eye lens.

Evidence on tissue expression from TISSUES for GJA8 Gene

  • Eye(4.5)

Phenotype-based relationships between genes and organs from Gene ORGANizer for GJA8 Gene

Germ Layers:
  • ectoderm
  • mesoderm
  • nervous
  • skeletal muscle
Head and neck:
  • brain
  • cranial nerve
  • eye
  • head
  • peripheral nervous system
genes like me logo Genes that share expression patterns with GJA8: view

Orthologs for GJA8 Gene

This gene was present in the common ancestor of chordates.

Orthologs for GJA8 Gene

Organism Taxonomy Gene Similarity Type Details
(Pan troglodytes)
Mammalia GJA8 34 33
  • 99.62 (n)
(Canis familiaris)
Mammalia GJA8 34 33
  • 88.43 (n)
(Bos Taurus)
Mammalia GJA8 34 33
  • 86.68 (n)
(Rattus norvegicus)
Mammalia Gja8 33
  • 86.07 (n)
(Mus musculus)
Mammalia Gja8 16 34 33
  • 85.6 (n)
(Ornithorhynchus anatinus)
Mammalia GJA8 34
  • 85 (a)
(Monodelphis domestica)
Mammalia GJA8 34
  • 85 (a)
(Gallus gallus)
Aves GJA8 34 33
  • 73.16 (n)
(Anolis carolinensis)
Reptilia GJA8 34
  • 68 (a)
tropical clawed frog
(Silurana tropicalis)
Amphibia gja8 33
  • 65 (n)
African clawed frog
(Xenopus laevis)
Amphibia Xl.23631 33
(Danio rerio)
Actinopterygii cx44.1 34 33
  • 70.61 (n)
cx50.5 34
  • 38 (a)
Species where no ortholog for GJA8 was found in the sources mined by GeneCards:
  • A. gosspyii yeast (Ashbya gossypii)
  • Actinobacteria (Mycobacterium tuberculosis)
  • African malaria mosquito (Anopheles gambiae)
  • Alicante grape (Vitis vinifera)
  • alpha proteobacteria (Wolbachia pipientis)
  • amoeba (Dictyostelium discoideum)
  • Archea (Pyrococcus horikoshii)
  • baker's yeast (Saccharomyces cerevisiae)
  • barley (Hordeum vulgare)
  • beta proteobacteria (Neisseria meningitidis)
  • bread mold (Neurospora crassa)
  • Chromalveolata (Phytophthora infestans)
  • common water flea (Daphnia pulex)
  • corn (Zea mays)
  • E. coli (Escherichia coli)
  • filamentous fungi (Aspergillus nidulans)
  • Firmicute bacteria (Streptococcus pneumoniae)
  • fission yeast (Schizosaccharomyces pombe)
  • fruit fly (Drosophila melanogaster)
  • green algae (Chlamydomonas reinhardtii)
  • honey bee (Apis mellifera)
  • K. lactis yeast (Kluyveromyces lactis)
  • loblloly pine (Pinus taeda)
  • malaria parasite (Plasmodium falciparum)
  • medicago trunc (Medicago Truncatula)
  • moss (Physcomitrella patens)
  • orangutan (Pongo pygmaeus)
  • pig (Sus scrofa)
  • rainbow trout (Oncorhynchus mykiss)
  • rice (Oryza sativa)
  • rice blast fungus (Magnaporthe grisea)
  • schistosome parasite (Schistosoma mansoni)
  • sea anemone (Nematostella vectensis)
  • sea squirt (Ciona intestinalis)
  • sea squirt (Ciona savignyi)
  • sea urchin (Strongylocentrotus purpuratus)
  • sorghum (Sorghum bicolor)
  • soybean (Glycine max)
  • stem rust fungus (Puccinia graminis)
  • sugarcane (Saccharum officinarum)
  • thale cress (Arabidopsis thaliana)
  • tomato (Lycopersicon esculentum)
  • toxoplasmosis (Toxoplasma gondii)
  • Trichoplax (Trichoplax adhaerens)
  • wheat (Triticum aestivum)
  • worm (Caenorhabditis elegans)

Evolution for GJA8 Gene

Gene Tree for GJA8 (if available)
Gene Tree for GJA8 (if available)
Evolutionary constrained regions (ECRs) for GJA8: view image

Paralogs for GJA8 Gene

Paralogs for GJA8 Gene

(16) SIMAP similar genes for GJA8 Gene using alignment to 1 proteins:

genes like me logo Genes that share paralogs with GJA8: view

Variants for GJA8 Gene

Sequence variations from dbSNP and Humsavar for GJA8 Gene

SNP ID Clin Chr 01 pos Variation AA Info Type
rs121434643 pathogenic, Cataract 1, not provided, Cataract 1, multiple types (CTRCT1) [MIM:116200] 147,908,094(+) G/A/C coding_sequence_variant, missense_variant
rs138140155 benign, likely-benign, Congenital cataract, Zonular Pulverulent Cataract, Cataract 1, not specified 147,908,613(+) A/G/T coding_sequence_variant, missense_variant
rs142376567 likely-benign, Zonular Pulverulent Cataract, Cataract 1 147,908,848(+) A/G coding_sequence_variant, missense_variant
rs142415337 conflicting-interpretations-of-pathogenicity, likely-benign, Cataract 1, Zonular Pulverulent Cataract 147,908,340(+) G/A coding_sequence_variant, missense_variant
rs143688085 uncertain-significance, Zonular Pulverulent Cataract, Cataract 1 147,908,949(+) G/A coding_sequence_variant, missense_variant

Structural Variations from Database of Genomic Variants (DGV) for GJA8 Gene

Variant ID Type Subtype PubMed ID
dgv327n100 CNV gain 25217958
dgv66e199 CNV deletion 23128226
esv2761299 CNV gain+loss 21179565
esv3587448 CNV gain 21293372
esv3894123 CNV gain 25118596
nsv1000564 CNV gain 25217958
nsv1003688 CNV gain 25217958
nsv1005055 CNV loss 25217958
nsv1132304 CNV duplication 24896259
nsv463517 CNV gain 19166990
nsv509457 CNV insertion 20534489
nsv510962 OTHER complex 20534489
nsv547678 CNV gain 21841781
nsv831437 CNV loss 17160897

Variation tolerance for GJA8 Gene

Residual Variation Intolerance Score: 34.8% of all genes are more intolerant (likely to be disease-causing)
Gene Damage Index Score: 1.05; 21.53% of all genes are more intolerant (likely to be disease-causing)

Additional Variant Information for GJA8 Gene

Human Gene Mutation Database (HGMD)
SNPedia medical, phenotypic, and genealogical associations of SNPs for

SNP Genotyping and Copy Number Assay Products

No data available for Polymorphic Variants from UniProtKB/Swiss-Prot for GJA8 Gene

Disorders for GJA8 Gene

MalaCards: The human disease database

(24) MalaCards diseases for GJA8 Gene - From: HGMD, OMIM, ClinVar, GTR, Orphanet, Swiss-Prot, DISEASES, Novoseek, and GeneCards

Disorder Aliases PubMed IDs
cataract 1, multiple types
  • ctrct1
cataract microcornea syndrome
  • microcornea cataract syndrome
cataract 25
  • ctrct25
sclerocornea, autosomal dominant
  • isolated congenital sclerocornea
cataract 30, multiple types
  • ctrct30
- elite association - COSMIC cancer census association via MalaCards
Search GJA8 in MalaCards View complete list of genes associated with diseases


  • Cataract 1, multiple types (CTRCT1) [MIM:116200]: An opacification of the crystalline lens of the eye that frequently results in visual impairment or blindness. Opacities vary in morphology, are often confined to a portion of the lens, and may be static or progressive. CTRCT1 includes congenital, zonular pulverulent, nuclear progressive, nuclear pulverulent, nuclear total, total, and posterior subcapsular types of cataract. Zonular or lamellar cataracts are opacities, broad or narrow, usually consisting of powdery white dots affecting only certain layers or zones between the cortex and nucleus of an otherwise clear lens. The opacity may be so dense as to render the entire central region of the lens completely opaque, or so translucent that vision is hardly if at all impeded. Zonular cataracts generally do not involve the embryonic nucleus, though sometimes they involve the fetal nucleus. Usually sharply separated from a clear cortex outside them, they may have projections from their outer edges known as riders or spokes. In some cases cataract is associated with microcornea without any other systemic anomaly or dysmorphism. Microcornea is defined by a corneal diameter inferior to 10 mm in both meridians in an otherwise normal eye. {ECO:0000269 PubMed:10480374, ECO:0000269 PubMed:11846744, ECO:0000269 PubMed:14627691, ECO:0000269 PubMed:16234473, ECO:0000269 PubMed:16604058, ECO:0000269 PubMed:18006672, ECO:0000269 PubMed:21174522, ECO:0000269 PubMed:21921990, ECO:0000269 PubMed:23508780, ECO:0000269 PubMed:9497259, ECO:0000269 Ref.4}. Note=The disease is caused by mutations affecting the gene represented in this entry.

Additional Disease Information for GJA8

Genetic Association Database
Human Genome Epidemiology Navigator
ATLAS of Genetics and Cytogenetics in Oncology and Haematology
genes like me logo Genes that share disorders with GJA8: view

No data available for Genatlas for GJA8 Gene

Publications for GJA8 Gene

  1. A missense mutation in the human connexin50 gene (GJA8) underlies autosomal dominant "zonular pulverulent" cataract, on chromosome 1q. (PMID: 9497259) Shiels A … Bhattacharya S (American journal of human genetics 1998) 2 3 4 22 58
  2. The human lens intrinsic membrane protein MP70 (Cx50) gene: clonal analysis and chromosome mapping. (PMID: 7796604) Church RL … Steele E (Current eye research 1995) 2 3 4 22 58
  3. The GJA8 allele encoding CX50I247M is a rare polymorphism, not a cataract-causing mutation. (PMID: 19756179) Graw J … Beyer EC (Molecular vision 2009) 3 4 22 58
  4. A novel connexin50 mutation associated with congenital nuclear pulverulent cataracts. (PMID: 18006672) Arora A … Moore AT (Journal of medical genetics 2008) 3 4 22 58
  5. A novel connexin 50 (GJA8) mutation in a Chinese family with a dominant congenital pulverulent nuclear cataract. (PMID: 18334966) Yan M … Zhou X (Molecular vision 2008) 3 22 44 58

Products for GJA8 Gene

Sources for GJA8 Gene

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