Seroatlas · Human Serome Atlas

METTL18

Histidine protein methyltransferase 1 homolog

Also known as: AsTP2, C1orf156, HPM1, MET18_HUMAN, MGC9084

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

Protein identityUniProt · HPA

UniProt accession: O95568
Gene: METTL18
Ensembl: ENSG00000171806
Chromosome: 1
Canonical length: 372 aa
Protein class: Enzymes, Predicted intracellular proteins
Subcellular location: Nucleoplasm,Cytosol

OverviewNCBI Gene

Enables heat shock protein binding activity and protein-L-histidine N-tele-methyltransferase activity. Involved in peptidyl-lysine monomethylation; regulation of gene expression; and regulation of ribosome biogenesis. Located in cytosol and nucleolus. Part of protein-containing complex. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

372 residues, UniProt reviewed canonical sequence.

>O95568|METTL18
     1  MTFQFNFTIE DHLENELTPI RDGALTLDSS KELSVSESQK GEERDRKCSA EQFDLPQDHL
    61  WEHKSMENAA PSQDTDSPLS AASSSRNLEP HGKQPSLRAA KEHAMPKDLK KMLENKVIET
   121  LPGFQHVKLS VVKTILLKEN FPGENIVSKS FSSHSDLITG VYEGGLKIWE CTFDLLAYFT
   181  KAKVKFAGKK VLDLGCGSGL LGITAFKGGS KEIHFQDYNS MVIDEVTLPN VVANSTLEDE
   241  ENDVNEPDVK RCRKPKVTQL YKCRFFSGEW SEFCKLVLSS EKLFVKYDLI LTSETIYNPD
   301  YYSNLHQTFL RLLSKNGRVL LASKAHYFGV GGGVHLFQKF VEERDVFKTR ILKIIDEGLK
   361  RFIIEITFKF PG

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against METTL18 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): 0.36
Highest tissue expression: 21 nTPM

Expression across tissuesHPA

Tissue

parathyroid gland: 21 nTPM
lymph node: 13 nTPM
tonsil: 11 nTPM
breast: 9.8 nTPM
thymus: 9.6 nTPM
ovary: 8.8 nTPM

Single-cell type

oocytes: 32 nCPM
late primary spermatocytes: 22 nCPM
esophageal apical cells: 19 nCPM
granulosa cells: 18 nCPM
early spermatids: 17 nCPM
syncytiotrophoblasts: 16 nCPM

Immune cell

T-reg: 35 nTPM
naive CD4 T-cell: 32 nTPM
MAIT T-cell: 32 nTPM
naive CD8 T-cell: 31 nTPM
memory CD8 T-cell: 29 nTPM
memory CD4 T-cell: 27 nTPM

Brain region

white matter: 7.3 nTPM
cerebellum: 7.2 nTPM
spinal cord: 5.6 nTPM
choroid plexus: 5.5 nTPM
pons: 5.4 nTPM
basal ganglia: 5.3 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): 1.39
gnomAD pLI: 0
gnomAD missense Z: 0.12
DepMap mean gene effect: 0.12
DepMap dependency class: none

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 METTL18 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 METTL18 as an antibody target. Whether an autoantibody or antibody against METTL18 could matter depends on whether native METTL18 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

METTL18 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 METTL18 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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