Seroatlas · Human Serome Atlas

JPH3

Junctophilin-3

Also known as: CAGL237, HDL2, JP-3, JP3, JPH3_HUMAN, TNRC22

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

Protein identityUniProt · HPA

UniProt accession
Q8WXH2
Gene
JPH3
Ensembl
ENSG00000154118
Chromosome
16
Canonical length
748 aa
Protein class
Disease related genes, Human disease related genes, Potential drug targets, Predicted membrane proteins, Transporters
Subcellular location
Nucleoplasm,Cytosol

OverviewNCBI Gene

Junctional complexes between the plasma membrane and endoplasmic/sarcoplasmic reticulum are a common feature of all excitable cell types and mediate cross talk between cell surface and intracellular ion channels. The protein encoded by this gene is a component of junctional complexes and is composed of a C-terminal hydrophobic segment spanning the endoplasmic/sarcoplasmic reticulum membrane and a remaining cytoplasmic domain that shows specific affinity for the plasma membrane. CAG/CTG repeat expansion from normally 6-28 repeats to 40-59 repeats in the 3' UTR of this gene have been associated with Huntington disease-like 2 (HDL2). This gene is a member of the junctophilin gene family. Alternatively spliced transcript variants have been described for this gene. [provided by RefSeq, Jul 2016]

Canonical amino-acid sequenceUniProt

748 residues, UniProt reviewed canonical sequence.

>Q8WXH2|JPH3
     1  MSSGGRFNFD DGGSYCGGWE DGKAHGHGVC TGPKGQGEYT GSWSHGFEVL GVYTWPSGNT
    61  YQGTWAQGKR HGIGLESKGK WVYKGEWTHG FKGRYGVREC AGNGAKYEGT WSNGLQDGYG
   121  TETYSDGGTY QGQWVGGMRQ GYGVRQSVPY GMAAVIRSPL RTSINSLRSE HTNGTALHPD
   181  ASPAVAGSPA VSRGGFVLVA HSDSEILKSK KKGLFRRSLL SGLKLRKSES KSSLASQRSK
   241  QSSFRSEAGM STVSSTASDI HSTISLGEAE AELAVIEDDI DATTTETYVG EWKNDKRSGF
   301  GVSQRSDGLK YEGEWASNRR HGYGCMTFPD GTKEEGKYKQ NILVGGKRKN LIPLRASKIR
   361  EKVDRAVEAA ERAATIAKQK AEIAASRTSH SRAKAEAALT AAQKAQEEAR IARITAKEFS
   421  PSFQHRENGL EYQRPKRQTS CDDIEVLSTG TPLQQESPEL YRKGTTPSDL TPDDSPLQSF
   481  PTSPAATPPP APAARNKVAH FSRQVSVDEE RGGDIQMLLE GRAGDCARSS WGEEQAGGSR
   541  GVRSGALRGG LLVDDFRTRG SGRKQPGNPK PRERRTESPP VFTWTSHHRA SNHSPGGSRL
   601  LELQEEKLSN YRMEMKPLLR METHPQKRRY SKGGACRGLG DDHRPEDRGF GVQRLRSKAQ
   661  NKENFRPASS AEPAVQKLAS LRLGGAEPRL LRWDLTFSPP QKSLPVALES DEENGDELKS
   721  STGSAPILVV MVILLNIGVA ILFINFFI

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against JPH3 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
1
Mean surface accessibility (rSASA)
0.5
Highest tissue expression
112 nTPM

Expression across tissuesHPA

Tissue

  • hippocampal formation: 112 nTPM
  • cerebral cortex: 109 nTPM
  • amygdala: 88 nTPM
  • basal ganglia: 72 nTPM
  • cerebellum: 52 nTPM
  • hypothalamus: 46 nTPM

Single-cell type

  • early spermatids: 63 nCPM
  • brain excitatory neurons: 63 nCPM
  • retinal amacrine cells: 52 nCPM
  • oocytes: 51 nCPM
  • other brain neurons: 49 nCPM
  • brain inhibitory neurons: 48 nCPM

Immune cell

  • basophil: 0 nTPM
  • classical monocyte: 0 nTPM
  • eosinophil: 0 nTPM
  • gdT-cell: 0 nTPM
  • intermediate monocyte: 0 nTPM
  • MAIT T-cell: 0 nTPM

Brain region

  • cerebral cortex: 187 nTPM
  • hippocampal formation: 155 nTPM
  • white matter: 105 nTPM
  • amygdala: 100 nTPM
  • basal ganglia: 100 nTPM
  • hypothalamus: 76 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about JPH3.

Disease | AllUniProt

Conditions JPH3 is implicated in, by any mechanism.

Disease | GeneticClinVar

1 pathogenic / likely-pathogenic of 269 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

  • Huntington disease-like 2

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)
0.2
gnomAD pLI
1
gnomAD missense Z
-0.32
DepMap mean gene effect
0.09
DepMap dependency class
none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 3% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads JPH3 as an antibody target. Whether an autoantibody or antibody against JPH3 could matter depends on whether native JPH3 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

JPH3 is annotated at the cell surface, where native JPH3 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 JPH3 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/JPH3. Study-independent annotations aggregated from UniProt, Human Protein Atlas, PubMed, IEDB, Pfam, InterPro, Gene Ontology, AlphaFold, gnomAD, DepMap, ClinVar, TCGA. Catalog release seroatlas-reviewed-human-uniprot-20260313.

Seroatlas is the reference for exploring autoantibody and antibody serology at the human-protein level: the autoreactome and human serome, multiplex serology (HuProt, HuScan, VirScan, PhIP-Seq).

© 2026 · Seroatlas, Discover Oregon LLC · Terms of use

Loading the interactive Seroatlas protein explorer...