Seroatlas · Human Serome Atlas

ST3GAL5

Lactosylceramide alpha-2,3-sialyltransferase

Also known as: SIAT9, SIAT9_HUMAN, SIATGM3S, ST3GalV

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

Protein identityUniProt · HPA

UniProt accession
Q9UNP4
Gene
ST3GAL5
Ensembl
ENSG00000115525
Chromosome
2
Canonical length
418 aa
Protein class
Disease related genes, Enzymes, Human disease related genes, Metabolic proteins, Potential drug targets, Predicted intracellular proteins, Predicted membrane proteins
Subcellular location
Vesicles

OverviewNCBI Gene

Ganglioside GM3 is known to participate in the induction of cell differentiation, modulation of cell proliferation, maintenance of fibroblast morphology, signal transduction, and integrin-mediated cell adhesion. The protein encoded by this gene is a type II membrane protein which catalyzes the formation of GM3 using lactosylceramide as the substrate. The encoded protein is a member of glycosyltransferase family 29 and may be localized to the Golgi apparatus. Mutation in this gene has been associated with Amish infantile epilepsy syndrome. Transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

418 residues, UniProt reviewed canonical sequence.

>Q9UNP4|ST3GAL5
     1  MRTKAAGCAE RRPLQPRTEA AAAPAGRAMP SEYTYVKLRS DCSRPSLQWY TRAQSKMRRP
    61  SLLLKDILKC TLLVFGVWIL YILKLNYTTE ECDMKKMHYV DPDHVKRAQK YAQQVLQKEC
   121  RPKFAKTSMA LLFEHRYSVD LLPFVQKAPK DSEAESKYDP PFGFRKFSSK VQTLLELLPE
   181  HDLPEHLKAK TCRRCVVIGS GGILHGLELG HTLNQFDVVI RLNSAPVEGY SEHVGNKTTI
   241  RMTYPEGAPL SDLEYYSNDL FVAVLFKSVD FNWLQAMVKK ETLPFWVRLF FWKQVAEKIP
   301  LQPKHFRILN PVIIKETAFD ILQYSEPQSR FWGRDKNVPT IGVIAVVLAT HLCDEVSLAG
   361  FGYDLNQPRT PLHYFDSQCM AAMNFQTMHN VTTETKFLLK LVKEGVVKDL SGGIDREF

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against ST3GAL5 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
1
Mean surface accessibility (rSASA)
0.33
Highest tissue expression
46 nTPM

Expression across tissuesHPA

Tissue

  • adrenal gland: 46 nTPM
  • spinal cord: 39 nTPM
  • basal ganglia: 34 nTPM
  • cerebral cortex: 32 nTPM
  • amygdala: 30 nTPM
  • retina: 29 nTPM

Single-cell type

  • pituicytes/fscs: 618 nCPM
  • retinal pigment epithelial cells: 558 nCPM
  • adrenal cortex cells: 522 nCPM
  • urothelial cells: 261 nCPM
  • alveolar cells type 2: 234 nCPM
  • oligodendrocytes: 208 nCPM

Immune cell

  • intermediate monocyte: 3 nTPM
  • non-classical monocyte: 2.4 nTPM
  • memory B-cell: 1.1 nTPM
  • classical monocyte: 0.8 nTPM
  • MAIT T-cell: 0.8 nTPM
  • naive B-cell: 0.7 nTPM

Brain region

  • white matter: 89 nTPM
  • basal ganglia: 62 nTPM
  • medulla oblongata: 58 nTPM
  • hypothalamus: 57 nTPM
  • thalamus: 55 nTPM
  • pons: 54 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about ST3GAL5.

Disease | AllUniProt

Conditions ST3GAL5 is implicated in, by any mechanism.

  • Salt and pepper developmental regression syndrome (SPDRS) MIM:609056

Disease | GeneticClinVar

51 pathogenic / likely-pathogenic of 507 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

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)
0.76
gnomAD pLI
0
gnomAD missense Z
1.05
DepMap mean gene effect
0.05
DepMap dependency class
none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 4% 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

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads ST3GAL5 as an antibody target. Whether an autoantibody or antibody against ST3GAL5 could matter depends on whether native ST3GAL5 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

ST3GAL5 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 ST3GAL5 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/ST3GAL5. 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).

© 2026 · Seroatlas, Discover Oregon LLC · Terms of use

Loading the interactive Seroatlas protein explorer...