Seroatlas · Human Serome Atlas

SEMG1

Semenogelin-1

Also known as: CT103, SEMG, SEMG1_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
P04279
Gene
SEMG1
Ensembl
ENSG00000124233
Chromosome
20
Canonical length
462 aa
Protein class
Plasma proteins, Predicted secreted proteins
Secretome location
Secreted in male reproductive system

OverviewNCBI Gene

The protein encoded by this gene is the predominant protein in semen. The encoded secreted protein is involved in the formation of a gel matrix that encases ejaculated spermatozoa. This preproprotein is proteolytically processed by the prostate-specific antigen (PSA) protease to generate multiple peptide products that exhibit distinct functions. One of these peptides, SgI-29, is an antimicrobial peptide with antibacterial activity. This proteolysis process also breaks down the gel matrix and allows the spermatozoa to move more freely. This gene and another similar semenogelin gene are present in a gene cluster on chromosome 20. [provided by RefSeq, Feb 2016]

Canonical amino-acid sequenceUniProt

462 residues, UniProt reviewed canonical sequence.

>P04279|SEMG1
     1  MKPNIIFVLS LLLILEKQAA VMGQKGGSKG RLPSEFSQFP HGQKGQHYSG QKGKQQTESK
    61  GSFSIQYTYH VDANDHDQSR KSQQYDLNAL HKTTKSQRHL GGSQQLLHNK QEGRDHDKSK
   121  GHFHRVVIHH KGGKAHRGTQ NPSQDQGNSP SGKGISSQYS NTEERLWVHG LSKEQTSVSG
   181  AQKGRKQGGS QSSYVLQTEE LVANKQQRET KNSHQNKGHY QNVVEVREEH SSKVQTSLCP
   241  AHQDKLQHGS KDIFSTQDEL LVYNKNQHQT KNLNQDQQHG RKANKISYQS SSTEERRLHY
   301  GENGVQKDVS QSSIYSQTEE KAQGKSQKQI TIPSQEQEHS QKANKISYQS SSTEERRLHY
   361  GENGVQKDVS QRSIYSQTEK LVAGKSQIQA PNPKQEPWHG ENAKGESGQS TNREQDLLSH
   421  EQKGRHQHGS HGGLDIVIIE QEDDSDRHLA QHLNNDRNPL FT

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SEMG1 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)
0.71
Highest tissue expression
28,650 nTPM

Expression across tissuesHPA

Tissue

  • seminal vesicle: 28,650 nTPM
  • prostate: 176 nTPM
  • urinary bladder: 4.8 nTPM
  • cervix: 1.3 nTPM
  • breast: 0.9 nTPM
  • gallbladder: 0.6 nTPM

Single-cell type

  • prostatic hillock cells: 3.1 nCPM
  • prostatic glandular cells: 2.9 nCPM
  • basal prostatic cells: 1.8 nCPM
  • prostatic club cells: 1.8 nCPM
  • fallopian secretory cells: 0.9 nCPM
  • neutrophils: 0.7 nCPM

Immune cell

  • eosinophil: 27 nTPM
  • neutrophil: 0.1 nTPM
  • basophil: 0 nTPM
  • classical monocyte: 0 nTPM
  • gdT-cell: 0 nTPM
  • intermediate monocyte: 0 nTPM

Brain region

  • spinal cord: 0.2 nTPM
  • amygdala: 0 nTPM
  • basal ganglia: 0 nTPM
  • cerebellum: 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 LOEUF (loss-of-function intolerance)
1.03
gnomAD pLI
0.36
gnomAD missense Z
-0.57
DepMap mean gene effect
0.1
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

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of SEMG1 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 SEMG1 as an antibody target. Whether an autoantibody or antibody against SEMG1 could matter depends on whether native SEMG1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

SEMG1 is annotated as secreted, so native SEMG1 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 SEMG1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/SEMG1. 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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