Seroatlas · Human Serome Atlas

AHCY

Adenosylhomocysteinase

Also known as: AdoHcyase, SAHH, SAHH_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
P23526
Gene
AHCY
Ensembl
ENSG00000101444
Chromosome
20
Canonical length
432 aa
Protein class
Disease related genes, Enzymes, Human disease related genes, Metabolic proteins, Plasma proteins, Potential drug targets, Predicted intracellular proteins
Subcellular location
Cytosol
Quaternary structure
Homotetramer

OverviewNCBI Gene

S-adenosylhomocysteine hydrolase belongs to the adenosylhomocysteinase family. It catalyzes the reversible hydrolysis of S-adenosylhomocysteine (AdoHcy) to adenosine (Ado) and L-homocysteine (Hcy). Thus, it regulates the intracellular S-adenosylhomocysteine (SAH) concentration thought to be important for transmethylation reactions. Deficiency in this protein is one of the different causes of hypermethioninemia. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jun 2009]

Canonical amino-acid sequenceUniProt

432 residues, UniProt reviewed canonical sequence.

>P23526|AHCY
     1  MSDKLPYKVA DIGLAAWGRK ALDIAENEMP GLMRMRERYS ASKPLKGARI AGCLHMTVET
    61  AVLIETLVTL GAEVQWSSCN IFSTQDHAAA AIAKAGIPVY AWKGETDEEY LWCIEQTLYF
   121  KDGPLNMILD DGGDLTNLIH TKYPQLLPGI RGISEETTTG VHNLYKMMAN GILKVPAINV
   181  NDSVTKSKFD NLYGCRESLI DGIKRATDVM IAGKVAVVAG YGDVGKGCAQ ALRGFGARVI
   241  ITEIDPINAL QAAMEGYEVT TMDEACQEGN IFVTTTGCID IILGRHFEQM KDDAIVCNIG
   301  HFDVEIDVKW LNENAVEKVN IKPQVDRYRL KNGRRIILLA EGRLVNLGCA MGHPSFVMSN
   361  SFTNQVMAQI ELWTHPDKYP VGVHFLPKKL DEAVAEAHLG KLNVKLTKLT EKQAQYLGMS
   421  CDGPFKPDHY RY

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against AHCY 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)
0.22
Highest tissue expression
177 nTPM

Expression across tissuesHPA

Tissue

  • liver: 177 nTPM
  • pancreas: 154 nTPM
  • kidney: 145 nTPM
  • esophagus: 137 nTPM
  • ovary: 112 nTPM
  • skeletal muscle: 104 nTPM

Single-cell type

  • tuft cells: 104 nCPM
  • colonocytes: 90 nCPM
  • late primary spermatocytes: 54 nCPM
  • esophageal apical cells: 50 nCPM
  • goblet cells: 41 nCPM
  • proximal tubule cells: 38 nCPM

Immune cell

  • intermediate monocyte: 61 nTPM
  • plasmacytoid DC: 55 nTPM
  • myeloid DC: 49 nTPM
  • non-classical monocyte: 41 nTPM
  • classical monocyte: 33 nTPM
  • total PBMC: 28 nTPM

Brain region

  • choroid plexus: 47 nTPM
  • white matter: 45 nTPM
  • pons: 43 nTPM
  • thalamus: 42 nTPM
  • hypothalamus: 41 nTPM
  • spinal cord: 41 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about AHCY.

Disease | AllUniProt

Conditions AHCY is implicated in, by any mechanism.

  • Hypermethioninemia with S-adenosylhomocysteine hydrolase deficiency (HMAHCHD) MIM:613752

Disease | GeneticClinVar

19 pathogenic / likely-pathogenic of 354 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)
0.62
gnomAD pLI
0.04
gnomAD missense Z
1.55
DepMap mean gene effect
-0.49
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 11% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Molecular functions

  • adenosylhomocysteinase activity

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

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

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

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