CSN1S1
Alpha-S1-casein
Also known as: CASA, CASA1_HUMAN, CSN1
Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene
Protein identityUniProt · HPA
- UniProt accession
- P47710
- Gene
- CSN1S1
- Ensembl
- ENSG00000126545
- Chromosome
- 4
- Canonical length
- 185 aa
- Protein class
- Cancer-related genes, Predicted intracellular proteins, Predicted secreted proteins
- Secretome location
- Secreted in female reproductive system
OverviewNCBI Gene
Predicted to be involved in several processes, including response to 11-deoxycorticosterone; response to dehydroepiandrosterone; and response to progesterone. Located in extracellular space. [provided by Alliance of Genome Resources, Jul 2025]
Canonical amino-acid sequenceUniProt
185 residues, UniProt reviewed canonical sequence.
>P47710|CSN1S1
1 MRLLILTCLV AVALARPKLP LRYPERLQNP SESSEPIPLE SREEYMNGMN RQRNILREKQ
61 TDEIKDTRNE STQNCVVAEP EKMESSISSS SEEMSLSKCA EQFCRLNEYN QLQLQAAHAQ
121 EQIRRMNENS HVQVPFQQLN QLAAYPYAVW YYPQIMQYVP FPPFSDISNP TAHENYEKNN
181 VMLQWLocalizationUniProt · AlphaFold · HPA
Whether an antibody against CSN1S1 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
- Secreted
- Secreted
- Yes
- Transmembrane segments
- 0
- Mean surface accessibility (rSASA)
- 0.62
- Highest tissue expression
- 1,290 nTPM
Expression across tissuesHPA
Tissue
- breast: 1,290 nTPM
- adipose tissue: 15 nTPM
- cerebral cortex: 1.6 nTPM
- hypothalamus: 1.3 nTPM
- salivary gland: 1.3 nTPM
- seminal vesicle: 1.2 nTPM
Single-cell type
- breast lactating cells: 90,952 nCPM
- breast secretory cells: 11 nCPM
- salivary acinar cells: 4.1 nCPM
- thymocytes: 2.5 nCPM
- salivary myoepithelial cells: 2.3 nCPM
- undifferentiated spermatogonia: 1 nCPM
Immune cell
- plasmacytoid DC: 0.8 nTPM
- NK-cell: 0.4 nTPM
- basophil: 0 nTPM
- classical monocyte: 0 nTPM
- eosinophil: 0 nTPM
- gdT-cell: 0 nTPM
Brain region
- hypothalamus: 1.3 nTPM
- cerebral cortex: 0.6 nTPM
- medulla oblongata: 0.4 nTPM
- amygdala: 0.3 nTPM
- pons: 0.2 nTPM
- white matter: 0.2 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)
- 1.71
- gnomAD pLI
- 0
- gnomAD missense Z
- 0.32
- DepMap mean gene effect
- -0.03
- DepMap dependency class
- selective
Cancer expressionTCGA
Across TCGA tumor cohorts, this protein is over-expressed in roughly 2% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).
OntologyGO
Biological processes
- response to dehydroepiandrosterone
- response to estradiol
- response to progesterone
- response to 11-deoxycorticosterone
Cellular components
Protein domainsUniProt · Pfam · InterPro
- Casein alpha/beta, conserved site
- Alpha-s1 casein
KeywordsUniProt
Antibody and autoantibody relevanceSeroatlas analysis
Seroatlas reads CSN1S1 as an antibody target. Whether an autoantibody or antibody against CSN1S1 could matter depends on whether native CSN1S1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.
CSN1S1 is annotated as secreted, so native CSN1S1 circulates and is directly accessible to antibodies. Secreted and cell-surface proteins are the autoantibody targets most likely to act like drugs, blocking or depleting the native protein.
Annotation status
The present source text does not explicitly label CSN1S1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.
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