Seroatlas · Human Serome Atlas

CABS1

Calcium-binding and spermatid-specific protein 1

Also known as: C4orf35, CABS1_HUMAN, CLPH, FLJ32897, NYD-SP26

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

Protein identityUniProt · HPA

UniProt accession: Q96KC9
Gene: CABS1
Ensembl: ENSG00000145309
Chromosome: 4
Canonical length: 395 aa
Protein class: Predicted intracellular proteins

OverviewNCBI Gene

Predicted to enable calcium ion binding activity. Predicted to be involved in flagellated sperm motility and spermatogenesis. Predicted to be located in acrosomal vesicle and sperm principal piece. Predicted to be active in mitochondrial inner membrane and motile cilium. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

395 residues, UniProt reviewed canonical sequence.

>Q96KC9|CABS1
     1  MAEDGLPKIY SHPPTESSKT PTAATIFFGA DNAIPKSETT ITSEGDHVTS VNEYMLESDF
    61  STTTDNKLTA KKEKLKSEDD MGTDFIKSTT HLQKEITSLT GTTNSITRDS ITEHFMPVKI
   121  GNISSPVTTV SLIDFSTDIA KEDILLATID TGDAEISITS EVSGTLKDSS AGVADAPAFP
   181  RKKDEADMSN YNSSIKSNVP ADEAVQVTDS TIPEAEIPPA PEESFTTIPD ITALEEEKIT
   241  EIDLSVLEDD TSAVATLTDS DEKFITVFEL TTSAEKDKDK REDTLLTDEE TTEGASIWME
   301  RDTANEAETH SVLLTAVESR YDFVVPASIA TNLVEESSTE EDLSETDNTE TVPKITEPFS
   361  GTTSVLDTPD YKEDTSTTET DIFELLKEEP DEFMI

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against CABS1 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: 0
Mean surface accessibility (rSASA): 0.71
Highest tissue expression: 102 nTPM

Expression across tissuesHPA

Tissue

testis: 102 nTPM
salivary gland: 4.4 nTPM
prostate: 0.1 nTPM
adipose tissue: 0 nTPM
adrenal gland: 0 nTPM
amygdala: 0 nTPM

Single-cell type

late spermatids: 8,201 nCPM
early spermatids: 1,589 nCPM
late primary spermatocytes: 239 nCPM
leydig cells: 10 nCPM
sertoli cells: 8.1 nCPM
early primary spermatocytes: 4.2 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

midbrain: 1.1 nTPM
thalamus: 0.3 nTPM
hypothalamus: 0.1 nTPM
amygdala: 0 nTPM
basal ganglia: 0 nTPM
cerebellum: 0 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): 1.34
gnomAD pLI: 0.01
gnomAD missense Z: -0.48
DepMap mean gene effect: 0.16
DepMap dependency class: none

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

Molecular functions

calcium ion binding

Cellular components

Protein domainsUniProt · Pfam · InterPro

Calcium-binding and spermatid-specific protein 1
Calcium-binding and spermatid-specific protein 1

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads CABS1 as an antibody target. Whether an autoantibody or antibody against CABS1 could matter depends on whether native CABS1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

CABS1 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 CABS1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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