Seroatlas · Human Serome Atlas

METTL21A

Protein N-lysine methyltransferase METTL21A

Also known as: FAM119A, HCA557b, HSPA-KMT, LOC151194, MT21A_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
Q8WXB1
Gene
METTL21A
Ensembl
ENSG00000144401
Chromosome
2
Canonical length
218 aa
Protein class
Predicted intracellular proteins, Predicted membrane proteins
Subcellular location
Nucleoplasm,Cytosol

OverviewNCBI Gene

Enables ATPase binding activity; Hsp70 protein binding activity; and protein-lysine N-methyltransferase activity. Involved in peptidyl-lysine methylation. Part of protein-containing complex. [provided by Alliance of Genome Resources, Apr 2025]

Canonical amino-acid sequenceUniProt

218 residues, UniProt reviewed canonical sequence.

>Q8WXB1|METTL21A
     1  MALVPYEETT EFGLQKFHKP LATFSFANHT IQIRQDWRHL GVAAVVWDAA IVLSTYLEMG
    61  AVELRGRSAV ELGAGTGLVG IVAALLGAHV TITDRKVALE FLKSNVQANL PPHIQTKTVV
   121  KELTWGQNLG SFSPGEFDLI LGADIIYLEE TFTDLLQTLE HLCSNHSVIL LACRIRYERD
   181  NNFLAMLERQ FTVRKVHYDP EKDVHIYEAQ KRNQKEDL

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against METTL21A 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
Intracellular
Secreted
No
Transmembrane segments
0
Mean surface accessibility (rSASA)
0.27
Highest tissue expression
23 nTPM

Expression across tissuesHPA

Tissue

  • liver: 23 nTPM
  • bone marrow: 21 nTPM
  • spinal cord: 19 nTPM
  • midbrain: 18 nTPM
  • basal ganglia: 17 nTPM
  • cerebral cortex: 16 nTPM

Single-cell type

  • cardiomyocytes: 157 nCPM
  • mast cells: 126 nCPM
  • late spermatids: 86 nCPM
  • cdc: 85 nCPM
  • neutrophil progenitors: 78 nCPM
  • microglia: 76 nCPM

Immune cell

  • eosinophil: 55 nTPM
  • memory B-cell: 54 nTPM
  • non-classical monocyte: 46 nTPM
  • naive B-cell: 44 nTPM
  • basophil: 31 nTPM
  • plasmacytoid DC: 30 nTPM

Brain region

  • choroid plexus: 26 nTPM
  • white matter: 26 nTPM
  • cerebellum: 25 nTPM
  • midbrain: 25 nTPM
  • medulla oblongata: 24 nTPM
  • spinal cord: 24 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)
1.36
gnomAD pLI
0
gnomAD missense Z
-0.04
DepMap mean gene effect
0.01
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 6% 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 METTL21A 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 METTL21A as an antibody target. Whether an autoantibody or antibody against METTL21A could matter depends on whether native METTL21A is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

METTL21A 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 METTL21A as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/METTL21A. 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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