Seroatlas · Human Serome Atlas

PSG1

Pregnancy-specific beta-1-glycoprotein 1

Also known as: CD66f, PBG1, PSBG1, PSG1_HUMAN, PSGGA

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

Protein identityUniProt · HPA

UniProt accession
P11464
Gene
PSG1
Ensembl
ENSG00000231924
Chromosome
19
Canonical length
419 aa
Protein class
CD markers, Predicted intracellular proteins, Predicted secreted proteins
Secretome location
Secreted in female reproductive system

OverviewNCBI Gene

The human placenta is a multihormonal endocrine organ that produces hormones, enzymes, and other molecules that support fetal survival and development. Pregnancy-specific beta-1-glycoprotein (PSBG, PSG) is a major product of the syncytiotrophoblast, reaching concentrations of 100 to 290 mg/l at term in the serum of pregnant women (Horne et al., 1976 [PubMed 971765]). PSG is a member of the immunoglobulin (Ig) superfamily (Watanabe and Chou, 1988 [PubMed 3257488]; Streydio et al., 1988 [PubMed 3260773]).[supplied by OMIM, Oct 2009]

Canonical amino-acid sequenceUniProt

419 residues, UniProt reviewed canonical sequence.

>P11464|PSG1
     1  MGTLSAPPCT QRIKWKGLLL TASLLNFWNL PTTAQVTIEA EPTKVSEGKD VLLLVHNLPQ
    61  NLTGYIWYKG QMRDLYHYIT SYVVDGEIII YGPAYSGRET AYSNASLLIQ NVTREDAGSY
   121  TLHIIKGDDG TRGVTGRFTF TLHLETPKPS ISSSNLNPRE TMEAVSLTCD PETPDASYLW
   181  WMNGQSLPMT HSLKLSETNR TLFLLGVTKY TAGPYECEIR NPVSASRSDP VTLNLLPKLP
   241  KPYITINNLN PRENKDVLNF TCEPKSENYT YIWWLNGQSL PVSPRVKRPI ENRILILPSV
   301  TRNETGPYQC EIRDRYGGIR SDPVTLNVLY GPDLPRIYPS FTYYRSGEVL YLSCSADSNP
   361  PAQYSWTINE KFQLPGQKLF IRHITTKHSG LYVCSVRNSA TGKESSKSMT VEVSDWTVP

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against PSG1 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)
0.34
Highest tissue expression
245 nTPM

Expression across tissuesHPA

Tissue

  • placenta: 245 nTPM
  • spleen: 0.6 nTPM
  • smooth muscle: 0.5 nTPM
  • stomach: 0.4 nTPM
  • lung: 0.3 nTPM
  • parathyroid gland: 0.2 nTPM

Single-cell type

  • syncytiotrophoblasts: 286 nCPM
  • retinal bipolar cells: 12 nCPM
  • cone photoreceptor cells: 8.3 nCPM
  • adipocytes: 6.9 nCPM
  • gonadotrophs: 3 nCPM
  • extravillous trophoblasts: 2.9 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: 7.1 nTPM
  • cerebral cortex: 5.6 nTPM
  • amygdala: 4.8 nTPM
  • thalamus: 4.4 nTPM
  • hippocampal formation: 4.2 nTPM
  • white matter: 4.2 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)
1.99
gnomAD pLI
0
gnomAD missense Z
-6.11
DepMap mean gene effect
-0.03
DepMap dependency class
none

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

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads PSG1 as an antibody target. Whether an autoantibody or antibody against PSG1 could matter depends on whether native PSG1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

PSG1 is annotated as secreted, so native PSG1 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 PSG1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/PSG1. 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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