Seroatlas · Human Serome Atlas

IDH3B

Isocitrate dehydrogenase [NAD] subunit beta, mitochondrial

Also known as: IDH3B_HUMAN, RP46

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

Protein identityUniProt · HPA

UniProt accession
O43837
Gene
IDH3B
Ensembl
ENSG00000101365
Chromosome
20
Canonical length
385 aa
Protein class
Citric acid cycle related proteins, Disease related genes, Human disease related genes, Metabolic proteins, Plasma proteins, Predicted intracellular proteins
Subcellular location
Mitochondria

OverviewNCBI Gene

Isocitrate dehydrogenases catalyze the oxidative decarboxylation of isocitrate to 2-oxoglutarate. These enzymes belong to two distinct subclasses, one of which utilizes NAD(+) as the electron acceptor and the other NADP(+). Five isocitrate dehydrogenases have been reported: three NAD(+)-dependent isocitrate dehydrogenases, which localize to the mitochondrial matrix, and two NADP(+)-dependent isocitrate dehydrogenases, one of which is mitochondrial and the other predominantly cytosolic. NAD(+)-dependent isocitrate dehydrogenases catalyze the allosterically regulated rate-limiting step of the tricarboxylic acid cycle. Each isozyme is a heterotetramer that is composed of two alpha subunits, one beta subunit, and one gamma subunit. The protein encoded by this gene is the beta subunit of one isozyme of NAD(+)-dependent isocitrate dehydrogenase. Multiple alternatively spliced transcript variants encoding different isoforms have been described for this gene. [provided by RefSeq, Sep 2016]

Canonical amino-acid sequenceUniProt

385 residues, UniProt reviewed canonical sequence.

>O43837|IDH3B
     1  MAALSGVRWL TRALVSAGNP GAWRGLSTSA AAHAASRSQA EDVRVEGSFP VTMLPGDGVG
    61  PELMHAVKEV FKAAAVPVEF QEHHLSEVQN MASEEKLEQV LSSMKENKVA IIGKIHTPME
   121  YKGELASYDM RLRRKLDLFA NVVHVKSLPG YMTRHNNLDL VIIREQTEGE YSSLEHESAR
   181  GVIECLKIVT RAKSQRIAKF AFDYATKKGR GKVTAVHKAN IMKLGDGLFL QCCEEVAELY
   241  PKIKFETMII DNCCMQLVQN PYQFDVLVMP NLYGNIIDNL AAGLVGGAGV VPGESYSAEY
   301  AVFETGARHP FAQAVGRNIA NPTAMLLSAS NMLRHLNLEY HSSMIADAVK KVIKVGKVRT
   361  RDMGGYSTTT DFIKSVIGHL QTKGS

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against IDH3B 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
Intracellular
Secreted
No
Transmembrane segments
0
Mean surface accessibility (rSASA)
0.3
Highest tissue expression
221 nTPM

Expression across tissuesHPA

Tissue

  • tongue: 221 nTPM
  • skeletal muscle: 191 nTPM
  • heart muscle: 176 nTPM
  • cerebellum: 78 nTPM
  • parathyroid gland: 71 nTPM
  • duodenum: 70 nTPM

Single-cell type

  • late spermatids: 169 nCPM
  • esophageal basal cells: 168 nCPM
  • cytotrophoblasts: 157 nCPM
  • migrating cytotrophoblasts: 142 nCPM
  • esophageal suprabasal cells: 141 nCPM
  • parietal cells: 131 nCPM

Immune cell

  • myeloid DC: 132 nTPM
  • intermediate monocyte: 121 nTPM
  • classical monocyte: 112 nTPM
  • non-classical monocyte: 111 nTPM
  • T-reg: 108 nTPM
  • total PBMC: 102 nTPM

Brain region

  • cerebellum: 64 nTPM
  • pons: 62 nTPM
  • medulla oblongata: 58 nTPM
  • cerebral cortex: 57 nTPM
  • thalamus: 55 nTPM
  • hypothalamus: 55 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about IDH3B.

Disease | AllUniProt

Conditions IDH3B is implicated in, by any mechanism.

Disease | GeneticClinVar

23 pathogenic / likely-pathogenic of 367 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

  • Retinitis pigmentosa 46

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)
1.26
gnomAD pLI
0
gnomAD missense Z
0.42
DepMap mean gene effect
-0.01
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 11% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads IDH3B as an antibody target. Whether an autoantibody or antibody against IDH3B could matter depends on whether native IDH3B is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

IDH3B is annotated as predominantly intracellular. Intracellular proteins are common autoantibody markers, becoming visible to the immune system after cell injury or altered processing, but are usually markers of disease rather than direct drivers.

Annotation status

The present source text does not explicitly label IDH3B as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/IDH3B. 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).

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