Seroatlas · Human Serome Atlas

SQOR

Sulfide:quinone oxidoreductase, mitochondrial

Also known as: CGI-44, SQOR_HUMAN, SQR, SQRDL

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

Protein identityUniProt · HPA

UniProt accession
Q9Y6N5
Gene
SQOR
Ensembl
ENSG00000137767
Chromosome
15
Canonical length
450 aa
Protein class
Disease related genes, Enzymes, Potential drug targets, Predicted intracellular proteins
Subcellular location
Mitochondria

OverviewNCBI Gene

The protein encoded by this gene may function in mitochondria to catalyze the conversion of sulfide to persulfides, thereby decreasing toxic concencrations of sulfide. Alternative splicing results in multiple transcript variants that encode the same protein. [provided by RefSeq, Sep 2012]

Canonical amino-acid sequenceUniProt

450 residues, UniProt reviewed canonical sequence.

>Q9Y6N5|SQOR
     1  MVPLVAVVSG PRAQLFACLL RLGTQQVGPL QLHTGASHAA RNHYEVLVLG GGSGGITMAA
    61  RMKRKVGAEN VAIVEPSERH FYQPIWTLVG AGAKQLSSSG RPTASVIPSG VEWIKARVTE
   121  LNPDKNCIHT DDDEKISYRY LIIALGIQLD YEKIKGLPEG FAHPKIGSNY SVKTVEKTWK
   181  ALQDFKEGNA IFTFPNTPVK CAGAPQKIMY LSEAYFRKTG KRSKANIIFN TSLGAIFGVK
   241  KYADALQEII QERNLTVNYK KNLIEVRADK QEAVFENLDK PGETQVISYE MLHVTPPMSP
   301  PDVLKTSPVA DAAGWVDVDK ETLQHRRYPN VFGIGDCTNL PTSKTAAAVA AQSGILDRTI
   361  SVIMKNQTPT KKYDGYTSCP LVTGYNRVIL AEFDYKAEPL ETFPFDQSKE RLSMYLMKAD
   421  LMPFLYWNMM LRGYWGGPAF LRKLFHLGMS

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SQOR 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)
0.26
Highest tissue expression
197 nTPM

Expression across tissuesHPA

Tissue

  • colon: 197 nTPM
  • rectum: 168 nTPM
  • skeletal muscle: 138 nTPM
  • esophagus: 122 nTPM
  • liver: 81 nTPM
  • salivary gland: 59 nTPM

Single-cell type

  • esophageal apical cells: 685 nCPM
  • colonocytes: 339 nCPM
  • esophageal suprabasal cells: 203 nCPM
  • enteric transient amplifying cells: 198 nCPM
  • neutrophils: 186 nCPM
  • enteric stem cells: 179 nCPM

Immune cell

  • neutrophil: 304 nTPM
  • classical monocyte: 212 nTPM
  • total PBMC: 170 nTPM
  • intermediate monocyte: 161 nTPM
  • non-classical monocyte: 153 nTPM
  • T-reg: 149 nTPM

Brain region

  • choroid plexus: 15 nTPM
  • white matter: 14 nTPM
  • medulla oblongata: 14 nTPM
  • spinal cord: 12 nTPM
  • thalamus: 12 nTPM
  • pons: 11 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about SQOR.

Disease | AllUniProt

Conditions SQOR is implicated in, by any mechanism.

  • Sulfide:quinone oxidoreductase deficiency (SQORD) MIM:619221

Disease | GeneticClinVar

2 pathogenic / likely-pathogenic of 75 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

  • Sulfide quinone oxidoreductase deficiency

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)
1.18
gnomAD pLI
0
DepMap mean gene effect
-0.09
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 SQOR as an antibody target. Whether an autoantibody or antibody against SQOR could matter depends on whether native SQOR is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

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

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