Seroatlas · Human Serome Atlas

SDC3

Syndecan-3

Also known as: N-syndecan, SDC3_HUMAN, SYND3

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

Protein identityUniProt · HPA

UniProt accession
O75056
Gene
SDC3
Ensembl
ENSG00000162512
Chromosome
1
Canonical length
442 aa
Protein class
Human disease related genes, Predicted membrane proteins
Subcellular location
Nucleoplasm,Mitochondria

OverviewNCBI Gene

The protein encoded by this gene belongs to the syndecan proteoglycan family. It may play a role in the organization of cell shape by affecting the actin cytoskeleton, possibly by transferring signals from the cell surface in a sugar-dependent mechanism. Allelic variants of this gene have been associated with obesity. [provided by RefSeq, Oct 2009]

Canonical amino-acid sequenceUniProt

442 residues, UniProt reviewed canonical sequence.

>O75056|SDC3
     1  MKPGPPHRAG AAHGAGAGAG AAAGPGARGL LLPPLLLLLL AGRAAGAQRW RSENFERPVD
    61  LEGSGDDDSF PDDELDDLYS GSGSGYFEQE SGIETAMRFS PDVALAVSTT PAVLPTTNIQ
   121  PVGTPFEELP SERPTLEPAT SPLVVTEVPE EPSQRATTVS TTMATTAATS TGDPTVATVP
   181  ATVATATPST PAAPPFTATT AVIRTTGVRR LLPLPLTTVA TARATTPEAP SPPTTAAVLD
   241  TEAPTPRLVS TATSRPRALP RPATTQEPDI PERSTLPLGT TAPGPTEVAQ TPTPETFLTT
   301  IRDEPEVPVS GGPSGDFELP EEETTQPDTA NEVVAVGGAA AKASSPPGTL PKGARPGPGL
   361  LDNAIDSGSS AAQLPQKSIL ERKEVLVAVI VGGVVGALFA AFLVTLLIYR MKKKDEGSYT
   421  LEEPKQASVT YQKPDKQEEF YA

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SDC3 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
Cell surface
Secreted
No
Transmembrane segments
1
Mean surface accessibility (rSASA)
0.7
Highest tissue expression
129 nTPM

Expression across tissuesHPA

Tissue

  • basal ganglia: 129 nTPM
  • adrenal gland: 113 nTPM
  • midbrain: 107 nTPM
  • amygdala: 104 nTPM
  • cerebral cortex: 93 nTPM
  • hypothalamus: 89 nTPM

Single-cell type

  • kupffer cells: 598 nCPM
  • oligodendrocyte progenitor cells: 195 nCPM
  • late spermatids: 154 nCPM
  • adrenal cortex cells: 102 nCPM
  • decidual stromal cells: 95 nCPM
  • schwann cells: 63 nCPM

Immune cell

  • basophil: 1 nTPM
  • intermediate monocyte: 0.6 nTPM
  • neutrophil: 0.6 nTPM
  • NK-cell: 0.4 nTPM
  • non-classical monocyte: 0.4 nTPM
  • classical monocyte: 0.3 nTPM

Brain region

  • medulla oblongata: 253 nTPM
  • thalamus: 224 nTPM
  • midbrain: 216 nTPM
  • basal ganglia: 216 nTPM
  • spinal cord: 197 nTPM
  • hypothalamus: 193 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)
0.66
gnomAD pLI
0.41
gnomAD missense Z
0.18
DepMap mean gene effect
-0.07
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 5% 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 SDC3 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 SDC3 as an antibody target. Whether an autoantibody or antibody against SDC3 could matter depends on whether native SDC3 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

SDC3 is annotated at the cell surface, where native SDC3 is exposed to circulating antibodies and is a prime autoantibody target that could block, deplete, or overstimulate it.

Annotation status

The present source text does not explicitly label SDC3 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/SDC3. 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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