Seroatlas · Human Serome Atlas

GALNT18

Polypeptide N-acetylgalactosaminyltransferase 18

Also known as: GalNAc-T18, GALNT15, GALNTL4, GLT18_HUMAN, MGC71806

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

Protein identityUniProt · HPA

UniProt accession
Q6P9A2
Gene
GALNT18
Ensembl
ENSG00000110328
Chromosome
11
Canonical length
607 aa
Protein class
Enzymes, Metabolic proteins, Predicted membrane proteins
Subcellular location
Golgi apparatus,Vesicles,Cytosol

OverviewNCBI Gene

Enables polypeptide N-acetylgalactosaminyltransferase activity. Involved in protein O-linked glycosylation. Predicted to be located in Golgi membrane. Predicted to be active in Golgi apparatus. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

607 residues, UniProt reviewed canonical sequence.

>Q6P9A2|GALNT18
     1  MVCTRKTKTL VSTCVILSGM TNIICLLYVG WVTNYIASVY VRGQEPAPDK KLEEDKGDTL
    61  KIIERLDHLE NVIKQHIQEA PAKPEEAEAE PFTDSSLFAH WGQELSPEGR RVALKQFQYY
   121  GYNAYLSDRL PLDRPLPDLR PSGCRNLSFP DSLPEVSIVF IFVNEALSVL LRSIHSAMER
   181  TPPHLLKEII LVDDNSSNEE LKEKLTEYVD KVNSQKPGFI KVVRHSKQEG LIRSRVSGWR
   241  AATAPVVALF DAHVEFNVGW AEPVLTRIKE NRKRIISPSF DNIKYDNFEI EEYPLAAQGF
   301  DWELWCRYLN PPKAWWKLEN STAPIRSPAL IGCFIVDRQY FQEIGLLDEG MEVYGGENVE
   361  LGIRVWQCGG SVEVLPCSRI AHIERAHKPY TEDLTAHVRR NALRVAEVWM DEFKSHVYMA
   421  WNIPQEDSGI DIGDITARKA LRKQLQCKTF RWYLVSVYPE MRMYSDIIAY GVLQNSLKTD
   481  LCLDQGPDTE NVPIMYICHG MTPQNVYYTS SQQIHVGILS PTVDDDDNRC LVDVNSRPRL
   541  IECSYAKAKR MKLHWQFSQG GPIQNRKSKR CLELQENSDL EFGFQLVLQK CSGQHWSITN
   601  VLRSLAS

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against GALNT18 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)
0.28
Highest tissue expression
49 nTPM

Expression across tissuesHPA

Tissue

  • lung: 49 nTPM
  • thyroid gland: 41 nTPM
  • kidney: 30 nTPM
  • heart muscle: 26 nTPM
  • blood vessel: 26 nTPM
  • colon: 24 nTPM

Single-cell type

  • vascular endothelial cells: 466 nCPM
  • proximal tubule cells: 444 nCPM
  • lymphatic endothelial cells: 426 nCPM
  • sertoli cells: 408 nCPM
  • loop of henle epithelial cells: 369 nCPM
  • alveolar cells type 1: 360 nCPM

Immune cell

  • gdT-cell: 0.1 nTPM
  • basophil: 0 nTPM
  • classical monocyte: 0 nTPM
  • eosinophil: 0 nTPM
  • intermediate monocyte: 0 nTPM
  • MAIT T-cell: 0 nTPM

Brain region

  • hippocampal formation: 56 nTPM
  • cerebral cortex: 37 nTPM
  • thalamus: 36 nTPM
  • amygdala: 34 nTPM
  • basal ganglia: 30 nTPM
  • midbrain: 30 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)
0.64
gnomAD pLI
0
gnomAD missense Z
0.88
DepMap mean gene effect
-0.02
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 GALNT18 as an antibody target. Whether an autoantibody or antibody against GALNT18 could matter depends on whether native GALNT18 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

GALNT18 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 GALNT18 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/GALNT18. 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...