Seroatlas · Human Serome Atlas

UQCC4

Ubiquinol-cytochrome c reductase complex assembly factor 4

Also known as: C16orf91, CCSMST1, gs103, UQCC4_HUMAN, URLC5

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

Protein identityUniProt · HPA

UniProt accession: Q4G0I0
Gene: UQCC4
Ensembl: ENSG00000174109
Chromosome: 16
Canonical length: 132 aa
Protein class: Predicted membrane proteins

OverviewNCBI Gene

Predicted to be involved in mitochondrial respiratory chain complex III assembly. Located in mitochondrion. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

132 residues, UniProt reviewed canonical sequence.

>Q4G0I0|UQCC4
     1  MNRVLCAPAA GAVRALRLIG WASRSLHPLP GSRDRAHPAA EEEDDPDRPI EFSSSKANPH
    61  RWSVGHTMGK GHQRPWWKVL PLSCFLVALI IWCYLREESE ADQWLRQVWG EVPEPSDRSE
   121  EPETPAAYRA RT

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against UQCC4 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: 1
Mean surface accessibility (rSASA): 0.67
Highest tissue expression: 17 nTPM

Expression across tissuesHPA

Tissue

adrenal gland: 17 nTPM
skeletal muscle: 16 nTPM
tongue: 15 nTPM
liver: 14 nTPM
heart muscle: 14 nTPM
cerebral cortex: 13 nTPM

Single-cell type

esophageal basal cells: 62 nCPM
suprabasal keratinocytes: 54 nCPM
esophageal suprabasal cells: 53 nCPM
syncytiotrophoblasts: 45 nCPM
cytotrophoblasts: 40 nCPM
migrating cytotrophoblasts: 39 nCPM

Immune cell

memory B-cell: 43 nTPM
NK-cell: 40 nTPM
plasmacytoid DC: 38 nTPM
MAIT T-cell: 34 nTPM
naive CD4 T-cell: 34 nTPM
naive B-cell: 33 nTPM

Brain region

cerebral cortex: 8.5 nTPM
choroid plexus: 8.3 nTPM
pons: 7.5 nTPM
hippocampal formation: 7.4 nTPM
basal ganglia: 6.9 nTPM
hypothalamus: 6.9 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): 1.83
gnomAD pLI: 0
DepMap mean gene effect: -0.1
DepMap dependency class: selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 6% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

mitochondrial respiratory chain complex III assembly

Cellular components

Protein domainsUniProt · Pfam · InterPro

Ubiquinol-cytochrome-c reductase complex assembly factor 4, vertebrates
Ubiquinol-cytochrome-c reductase complex assembly factor 4
CCSMST1 family

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads UQCC4 as an antibody target. Whether an autoantibody or antibody against UQCC4 could matter depends on whether native UQCC4 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

UQCC4 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 UQCC4 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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