Seroatlas · Human Serome Atlas

SMCP

Sperm mitochondrial-associated cysteine-rich protein

Also known as: MCSP, MCSP_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
P49901
Gene
SMCP
Ensembl
ENSG00000163206
Chromosome
1
Canonical length
116 aa
Protein class
Predicted intracellular proteins

OverviewNCBI Gene

Sperm mitochondria differ in morphology and subcellular localization from those of somatic cells. They are elongated, flattened, and arranged circumferentially to form a helical coiled sheath in the midpiece of the sperm flagellum. The protein encoded by this gene localizes to the capsule associated with the mitochondrial outer membranes and is thought to function in the organization and stabilization of the helical structure of the sperm's mitochondrial sheath. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

116 residues, UniProt reviewed canonical sequence.

>P49901|SMCP
     1  MCDQTKHSKC CPAKGNQCCP PQQNQCCQSK GNQCCPPKQN QCCQPKGSQC CPPKHNHCCQ
    61  PKPPCCIQAR CCGLETKPEV SPLNMESEPN SPQTQDKGCQ TQQQPHSPQN ESRPSK

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SMCP 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)
0.73
Highest tissue expression
717 nTPM

Expression across tissuesHPA

Tissue

  • testis: 717 nTPM
  • cerebellum: 1.2 nTPM
  • cerebral cortex: 0.8 nTPM
  • prostate: 0.6 nTPM
  • breast: 0.5 nTPM
  • basal ganglia: 0.4 nTPM

Single-cell type

  • late spermatids: 24,930 nCPM
  • early spermatids: 3,991 nCPM
  • late primary spermatocytes: 1,426 nCPM
  • sertoli cells: 40 nCPM
  • leydig cells: 33 nCPM
  • peritubular myoid cells: 18 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

  • cerebellum: 0.6 nTPM
  • hypothalamus: 0.2 nTPM
  • amygdala: 0 nTPM
  • basal ganglia: 0 nTPM
  • cerebral cortex: 0 nTPM
  • choroid plexus: 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 missense Z
-0.14
DepMap mean gene effect
0.1
DepMap dependency class
selective

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

Cellular components

Protein domainsUniProt · Pfam · InterPro

  • Sperm mitochondrial-associated cysteine-rich protein

KeywordsUniProt

InteractionsUniProt · HPA

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

Antibody and autoantibody relevanceSeroatlas analysis

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

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

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