Seroatlas · Human Serome Atlas

CYB5D1

Cytochrome b5 domain-containing protein 1

Also known as: CB5D1_HUMAN, FLJ32499

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

Protein identityUniProt · HPA

UniProt accession: Q6P9G0
Gene: CYB5D1
Ensembl: ENSG00000182224
Chromosome: 17
Canonical length: 228 aa
Protein class: Metabolic proteins, Predicted intracellular proteins
Subcellular location: Nucleoli,Golgi apparatus

OverviewNCBI Gene

Predicted to enable metal ion binding activity. Predicted to be involved in cilium movement and regulation of cilium beat frequency. Predicted to be located in cell projection; cytoplasm; and cytoskeleton. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

228 residues, UniProt reviewed canonical sequence.

>Q6P9G0|CYB5D1
     1  MPRRGLVAGP DLEYFQRRYF TPAEVAQHNR PEDLWVSYLG RVYDLTSLAQ EYKGNLLLKP
    61  IVEVAGQDIS HWFDPKTRDI RKHIDPLTGC LRYCTPRGRF VHVPPQLPCS DWANDFGKPW
   121  WQGSYYEVGR LSAKTRSIRI INTLTSQEHT LEVGVLESIW EILHRYLPYN SHAASYTWKY
   181  EGKNLNMDFT LEENGIRDEE EEFDYLSMDG TLHTPAILLY FNDDLTEL

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against CYB5D1 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): 0.32
Highest tissue expression: 28 nTPM

Expression across tissuesHPA

Tissue

retina: 28 nTPM
fallopian tube: 25 nTPM
choroid plexus: 21 nTPM
thyroid gland: 20 nTPM
kidney: 17 nTPM
adipose tissue: 16 nTPM

Single-cell type

early spermatids: 46 nCPM
late spermatids: 29 nCPM
ependymal cells: 25 nCPM
choroid plexus epithelial cells: 14 nCPM
epicardial cells: 11 nCPM
hepatic stellate cells: 6.5 nCPM

Immune cell

naive CD4 T-cell: 2.1 nTPM
memory B-cell: 1.2 nTPM
myeloid DC: 1.2 nTPM
naive CD8 T-cell: 1.2 nTPM
MAIT T-cell: 1.1 nTPM
gdT-cell: 1 nTPM

Brain region

choroid plexus: 33 nTPM
hypothalamus: 23 nTPM
midbrain: 22 nTPM
medulla oblongata: 21 nTPM
cerebellum: 19 nTPM
cerebral cortex: 19 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
gnomAD missense Z: 0.86
DepMap mean gene effect: 0.04
DepMap dependency class: none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 3% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Molecular functions

metal ion binding

Cellular components

axoneme

Protein domainsUniProt · Pfam · InterPro

Cytochrome b5-like heme/steroid binding domain
Cytochrome b5-like heme/steroid binding domain superfamily
Cytochrome b5-like Heme/Steroid binding domain
Cytochrome b5 domain-containing

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads CYB5D1 as an antibody target. Whether an autoantibody or antibody against CYB5D1 could matter depends on whether native CYB5D1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

CYB5D1 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 CYB5D1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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