Seroatlas · Human Serome Atlas

SDHD

Succinate dehydrogenase [ubiquinone] cytochrome b small subunit, mitochondrial

Also known as: cybS, DHSD_HUMAN, PGL, PGL1

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

Protein identityUniProt · HPA

UniProt accession
O14521
Gene
SDHD
Ensembl
ENSG00000204370
Chromosome
11
Canonical length
159 aa
Protein class
Cancer-related genes, Citric acid cycle related proteins, Disease related genes, FDA approved drug targets, Human disease related genes, Metabolic proteins, Predicted intracellular proteins, Predicted membrane proteins, Transporters

OverviewNCBI Gene

This gene encodes a member of complex II of the respiratory chain, which is responsible for the oxidation of succinate. The encoded protein is one of two integral membrane proteins anchoring the complex to the matrix side of the mitochondrial inner membrane. Mutations in this gene are associated with the formation of tumors, including hereditary paraganglioma. Transmission of disease occurs almost exclusively through the paternal allele, suggesting that this locus may be maternally imprinted. There are pseudogenes for this gene on chromosomes 1, 2, 3, 7, and 18. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Feb 2013]

Canonical amino-acid sequenceUniProt

159 residues, UniProt reviewed canonical sequence.

>O14521|SDHD
     1  MAVLWRLSAV CGALGGRALL LRTPVVRPAH ISAFLQDRPI PEWCGVQHIH LSPSHHSGSK
    61  AASLHWTSER VVSVLLLGLL PAAYLNPCSA MDYSLAAALT LHGHWGLGQV VTDYVHGDAL
   121  QKAAKAGLLA LSALTFAGLC YFNYHDVGIC KAVAMLWKL

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SDHD 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
Other membrane
Secreted
No
Transmembrane segments
3
Mean surface accessibility (rSASA)
0.52
Highest tissue expression
420 nTPM

Expression across tissuesHPA

Tissue

  • tongue: 420 nTPM
  • liver: 366 nTPM
  • skeletal muscle: 332 nTPM
  • kidney: 298 nTPM
  • heart muscle: 238 nTPM
  • duodenum: 196 nTPM

Single-cell type

  • late spermatids: 18 nCPM
  • esophageal apical cells: 7.9 nCPM
  • fallopian secretory cells: 7.7 nCPM
  • respiratory ionocytes: 7.6 nCPM
  • parietal cells: 7.1 nCPM
  • monocyte progenitors: 7 nCPM

Immune cell

  • intermediate monocyte: 391 nTPM
  • total PBMC: 349 nTPM
  • non-classical monocyte: 325 nTPM
  • myeloid DC: 309 nTPM
  • classical monocyte: 294 nTPM
  • neutrophil: 259 nTPM

Brain region

  • cerebellum: 59 nTPM
  • white matter: 58 nTPM
  • hypothalamus: 52 nTPM
  • choroid plexus: 52 nTPM
  • spinal cord: 51 nTPM
  • thalamus: 50 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about SDHD.

Disease | AllUniProt

Conditions SDHD is implicated in, by any mechanism.

  • Pheochromocytoma/paraganglioma syndrome 1 (PPGL1) MIM:168000
  • Paraganglioma and gastric stromal sarcoma (PGGSS) MIM:606864
  • Mitochondrial complex II deficiency, nuclear type 3 (MC2DN3) MIM:619167

Disease | GeneticClinVar

162 pathogenic / likely-pathogenic of 921 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

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)
0.73
gnomAD pLI
0.34
gnomAD missense Z
-0.17
DepMap mean gene effect
-0.49
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 4% 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 SDHD as an antibody target. Whether an autoantibody or antibody against SDHD could matter depends on whether native SDHD is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

SDHD 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 SDHD as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/SDHD. 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...