Seroatlas · Human Serome Atlas

CT45A1

Cancer/testis antigen family 45 member A1

Also known as: CT45-1, CT45.1, CT451_HUMAN

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

Protein identityUniProt · HPA

UniProt accession: Q5HYN5
Gene: CT45A1
Ensembl: ENSG00000268940
Chromosome: X
Canonical length: 189 aa
Protein class: Predicted intracellular proteins
Subcellular location: Nucleoplasm,Nucleoli

OverviewNCBI Gene

Located in nucleus. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

189 residues, UniProt reviewed canonical sequence.

>Q5HYN5|CT45A1
     1  MTDKTEKVAV DPETVFKRPR ECDSPSYQKR QRMALLARKQ GAGDSLIAGS AMSKAKKLMT
    61  GHAIPPSQLD SQIDDFTGFS KDRMMQKPGS NAPVGGNVTS SFSGDDLECR ETASSPKSQR
   121  EINADIKRKL VKELRCVGQK YEKIFEMLEG VQGPTAVRKR FFESIIKEAA RCMRRDFVKH
   181  LKKKLKRMI

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against CT45A1 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): 0.56
Highest tissue expression: 13 nTPM

Expression across tissuesHPA

Tissue

testis: 13 nTPM
hippocampal formation: 2.4 nTPM
basal ganglia: 2.1 nTPM
hypothalamus: 2.1 nTPM
spinal cord: 2.1 nTPM
amygdala: 2 nTPM

Single-cell type

early primary spermatocytes: 7.5 nCPM
differentiating spermatogonia: 6.6 nCPM
other brain neurons: 0.7 nCPM
salivary myoepithelial cells: 0.3 nCPM
brain inhibitory neurons: 0.2 nCPM
vascular endothelial cells: 0.2 nCPM

Immune cell

basophil: 0 nTPM
classical monocyte: 0 nTPM
eosinophil: 0 nTPM
gdT-cell: 0 nTPM
intermediate monocyte: 0 nTPM
MAIT T-cell: 0 nTPM

Brain region

thalamus: 0.8 nTPM
medulla oblongata: 0.6 nTPM
pons: 0.6 nTPM
basal ganglia: 0.5 nTPM
amygdala: 0.4 nTPM
midbrain: 0.4 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): 1.88
gnomAD pLI: 0.3
gnomAD missense Z: 0.7

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

Cellular components

nucleus

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

Nucleus

InteractionsUniProt · HPA

Protein binding partners of CT45A1 in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

CSNK2A1

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads CT45A1 as an antibody target. Whether an autoantibody or antibody against CT45A1 could matter depends on whether native CT45A1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

CT45A1 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 CT45A1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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