Seroatlas · Human Serome Atlas

XXYLT1

Xyloside xylosyltransferase 1

Also known as: C3orf21, FLJ35155, XXLT1_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
Q8NBI6
Gene
XXYLT1
Ensembl
ENSG00000173950
Chromosome
3
Canonical length
393 aa
Protein class
Enzymes, Predicted intracellular proteins
Quaternary structure
Homodimer

OverviewNCBI Gene

Enables magnesium ion binding activity; manganese ion binding activity; and xylosyl alpha-1,3-xylosyltransferase activity. Involved in O-glycan processing. Located in endoplasmic reticulum membrane. [provided by Alliance of Genome Resources, Apr 2025]

Canonical amino-acid sequenceUniProt

393 residues, UniProt reviewed canonical sequence.

>Q8NBI6|XXYLT1
     1  MGLLRGGLPC ARAMARLGAV RSHYCALLLA AALAVCAFYY LGSGRETFSS ATKRLKEARA
    61  GAPAAPSPPA LELARGSVAP APGAKAKSLE GGGAGPVDYH LLMMFTKAEH NAALQAKARV
   121  ALRSLLRLAK FEAHEVLNLH FVSEEASREV AKGLLRELLP PAAGFKCKVI FHDVAVLTDK
   181  LFPIVEAMQK HFSAGLGTYY SDSIFFLSVA MHQIMPKEIL QIIQLDLDLK FKTNIRELFE
   241  EFDSFLPGAI IGIAREMQPV YRHTFWQFRH ENPQTRVGGP PPEGLPGFNS GVMLLNLEAM
   301  RQSPLYSRLL EPAQVQQLAD KYHFRGHLGD QDFFTMIGME HPKLFHVLDC TWNRQLCTWW
   361  RDHGYSDVFE AYFRCEGHVK IYHGNCNTPI PED

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against XXYLT1 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)
0.32
Highest tissue expression
11 nTPM

Expression across tissuesHPA

Tissue

  • esophagus: 11 nTPM
  • placenta: 9.8 nTPM
  • skin: 8.8 nTPM
  • endometrium: 8.6 nTPM
  • smooth muscle: 8.1 nTPM
  • cervix: 7.9 nTPM

Single-cell type

  • pdcs: 89 nCPM
  • somatotrophs: 82 nCPM
  • choroid plexus epithelial cells: 81 nCPM
  • bergmann glia: 74 nCPM
  • megakaryocyte-erythroid progenitors: 68 nCPM
  • thyrotrophs: 61 nCPM

Immune cell

  • plasmacytoid DC: 10 nTPM
  • classical monocyte: 3.9 nTPM
  • myeloid DC: 2.7 nTPM
  • intermediate monocyte: 2.6 nTPM
  • non-classical monocyte: 2.3 nTPM
  • naive B-cell: 2.2 nTPM

Brain region

  • hypothalamus: 15 nTPM
  • pons: 15 nTPM
  • cerebral cortex: 13 nTPM
  • choroid plexus: 13 nTPM
  • basal ganglia: 13 nTPM
  • medulla oblongata: 12 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)
1.11
gnomAD pLI
0
gnomAD missense Z
0.52
DepMap mean gene effect
-0.12
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 12% 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 XXYLT1 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 XXYLT1 as an antibody target. Whether an autoantibody or antibody against XXYLT1 could matter depends on whether native XXYLT1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

XXYLT1 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 XXYLT1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/XXYLT1. 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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