Seroatlas · Human Serome Atlas

GJD2

Gap junction delta-2 protein

Also known as: CX36, CXD2_HUMAN, GJA9

Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene

Protein identityUniProt · HPA

UniProt accession: Q9UKL4
Gene: GJD2
Ensembl: ENSG00000159248
Chromosome: 15
Canonical length: 321 aa
Protein class: Predicted membrane proteins, Transporters

OverviewNCBI Gene

This gene encodes a member of the connexin protein family. Connexins are gap junction proteins which are arranged in groups of 6 around a central pore to form a connexon, a component of the gap junction intercellular channel. The channels formed by this protein allow cationic molecule exchange between human beta cells and may function in the regulation of insulin secretion. [provided by RefSeq, Oct 2012]

Canonical amino-acid sequenceUniProt

321 residues, UniProt reviewed canonical sequence.

>Q9UKL4|GJD2
     1  MGEWTILERL LEAAVQQHST MIGRILLTVV VIFRILIVAI VGETVYDDEQ TMFVCNTLQP
    61  GCNQACYDRA FPISHIRYWV FQIIMVCTPS LCFITYSVHQ SAKQRERRYS TVFLALDRDP
   121  PESIGGPGGT GGGGSGGGKR EDKKLQNAIV NGVLQNTENT SKETEPDCLE VKELTPHPSG
   181  LRTASKSKLR RQEGISRFYI IQVVFRNALE IGFLVGQYFL YGFSVPGLYE CNRYPCIKEV
   241  ECYVSRPTEK TVFLVFMFAV SGICVVLNLA ELNHLGWRKI KLAVRGAQAK RKSIYEIRNK
   301  DLPRVSVPNF GRTQSSDSAY V

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against GJD2 can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.

Antibody reachability: Cell surface
Secreted: No
Transmembrane segments: 4
Mean surface accessibility (rSASA): 0.46
Highest tissue expression: 20 nTPM

Expression across tissuesHPA

Tissue

retina: 20 nTPM
pituitary gland: 7.3 nTPM
adrenal gland: 5.6 nTPM
heart muscle: 4.3 nTPM
pancreas: 3.7 nTPM
cerebral cortex: 1.7 nTPM

Single-cell type

cone photoreceptor cells: 33 nCPM
adrenal medulla cells: 21 nCPM
somatotrophs: 20 nCPM
pancreatic islet cells: 16 nCPM
rod photoreceptor cells: 10 nCPM
retinal bipolar cells: 5.9 nCPM

Immune cell

basophil: 0.3 nTPM
neutrophil: 0.2 nTPM
eosinophil: 0.1 nTPM
NK-cell: 0.1 nTPM
non-classical monocyte: 0.1 nTPM
classical monocyte: 0 nTPM

Brain region

medulla oblongata: 7.4 nTPM
hypothalamus: 4.5 nTPM
cerebral cortex: 3.9 nTPM
midbrain: 3.6 nTPM
cerebellum: 3.3 nTPM
basal ganglia: 3.2 nTPM

Genetic constraint and essentialitygnomAD · DepMap

Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.

gnomAD LOEUF (loss-of-function intolerance): 0.7
gnomAD pLI: 0.2
gnomAD missense Z: 2.43
DepMap mean gene effect: 0.09
DepMap dependency class: none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 2% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Molecular functions

gap junction channel activity

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads GJD2 as an antibody target. Whether an autoantibody or antibody against GJD2 could matter depends on whether native GJD2 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

GJD2 is annotated at the cell surface, where native GJD2 is exposed to circulating antibodies and is a prime autoantibody target that could block, deplete, or overstimulate it.

Annotation status

The present source text does not explicitly label GJD2 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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