Seroatlas · Human Serome Atlas

CYB561

Transmembrane ascorbate-dependent reductase CYB561

Also known as: CY561_HUMAN, CYB561A1, FRRS2

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

Protein identityUniProt · HPA

UniProt accession
P49447
Gene
CYB561
Ensembl
ENSG00000008283
Chromosome
17
Canonical length
251 aa
Protein class
Disease related genes, Potential drug targets, Predicted membrane proteins, Transporters

OverviewNCBI Gene

Predicted to enable transmembrane monodehydroascorbate reductase activity. Predicted to be involved in ascorbate homeostasis. Predicted to be located in chromaffin granule membrane. Predicted to be active in lysosomal membrane. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

251 residues, UniProt reviewed canonical sequence.

>P49447|CYB561
     1  MEGGAAAATP TALPYYVAFS QLLGLTLVAM TGAWLGLYRG GIAWESDLQF NAHPLCMVIG
    61  LIFLQGNALL VYRVFRNEAK RTTKVLHGLL HIFALVIALV GLVAVFDYHR KKGYADLYSL
   121  HSWCGILVFV LYFVQWLVGF SFFLFPGASF SLRSRYRPQH IFFGATIFLL SVGTALLGLK
   181  EALLFNLGGK YSAFEPEGVL ANVLGLLLAC FGGAVLYILT RADWKRPSQA EEQALSMDFK
   241  TLTEGDSPGS Q

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against CYB561 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
6
Mean surface accessibility (rSASA)
0.31
Highest tissue expression
119 nTPM

Expression across tissuesHPA

Tissue

  • adrenal gland: 119 nTPM
  • pancreas: 116 nTPM
  • choroid plexus: 100 nTPM
  • salivary gland: 85 nTPM
  • pituitary gland: 73 nTPM
  • parathyroid gland: 72 nTPM

Single-cell type

  • adrenal medulla cells: 287 nCPM
  • esophageal apical cells: 176 nCPM
  • respiratory ciliated cells: 153 nCPM
  • fallopian tube ciliated cells: 138 nCPM
  • prostatic glandular cells: 122 nCPM
  • epididymal principal cells: 121 nCPM

Immune cell

  • MAIT T-cell: 25 nTPM
  • NK-cell: 20 nTPM
  • gdT-cell: 19 nTPM
  • memory CD4 T-cell: 14 nTPM
  • memory CD8 T-cell: 13 nTPM
  • non-classical monocyte: 7.7 nTPM

Brain region

  • pons: 273 nTPM
  • choroid plexus: 157 nTPM
  • hypothalamus: 74 nTPM
  • midbrain: 55 nTPM
  • basal ganglia: 54 nTPM
  • cerebral cortex: 52 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about CYB561.

Disease | AllUniProt

Conditions CYB561 is implicated in, by any mechanism.

Disease | GeneticClinVar

2 pathogenic / likely-pathogenic of 46 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

  • Orthostatic hypotension 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)
0.54
gnomAD pLI
0.61
gnomAD missense Z
0.95
DepMap mean gene effect
-0.23
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

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads CYB561 as an antibody target. Whether an autoantibody or antibody against CYB561 could matter depends on whether native CYB561 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

CYB561 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 CYB561 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/CYB561. 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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