{"entity":{"id":"atp4a","kind":"target","name":"ATP4A","aka":["ATPase H+/K+ transporting subunit alpha","Potassium-transporting ATPase alpha chain 1","ATP6A"],"tldr":"ATP4A (Potassium-transporting ATPase alpha chain 1) is a gene. The public catalogues list it as a drug target, and an approved or late-stage drug is recorded against it. Tied to Gastric & gastro-oesophageal junction cancer and Non-Hodgkin lymphoma.","summary":"The catalytic subunit of the gastric H(+)/K(+) ATPase pump which transports H(+) ions in exchange for K(+) ions across the apical membrane of parietal cells. Uses ATP as an energy source to pump H(+) ions to the gastric lumen while transporting K(+) ion from the lumen into the cell. Remarkably generates a million-fold proton gradient across the gastric parietal cell membrane, acidifying the gastric juice down to pH 1.\n\nOpen Targets scores its association with cancer at 0.58 (direct and indirect evidence; datatypes literature 0.45, animal model 0.65, genetic association 0.00, clinical 0.91).","asOf":"2026-09-23","links":[{"label":"HGNC HGNC:819","url":"https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:819"},{"label":"UniProt P20648","url":"https://www.uniprot.org/uniprotkb/P20648/entry"},{"label":"NCBI Gene 495","url":"https://www.ncbi.nlm.nih.gov/gene/495"},{"label":"Ensembl ENSG00000105675","url":"https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000105675"}],"tags":["cancer-genes-wave"],"related":["open-targets"],"cancers":["gastric","non-hodgkin-lymphoma"],"sections":[],"technologies":[],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":["Written by scripts/fetch-cancer-genes.ts from CIViC, Open Targets, IntOGen, HGNC and UniProt; the function text is UniProt's, condensed and in UK spelling. Roles: Open Targets known-drug datatype score 0.91. Evidence tier \"approved-drug\" is the strongest of those signals.","Prevalence not recorded: none of the sources gives a positivity rate."],"provenance":{"editedBy":"scripts/fetch-cancer-genes.ts (CIViC, Open Targets, IntOGen, HGNC, UniProt)","editedOn":"2026-09-23"},"symbol":"ATP4A","role":["drug-target"],"evidenceTier":"approved-drug","sources":[{"label":"HGNC HGNC:819","url":"https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:819","note":"approved symbol, name, aliases, locus and cross-references (hgnc_complete_set.txt)"},{"label":"UniProt P20648","url":"https://www.uniprot.org/uniprotkb/P20648/entry","note":"protein name, function text, keywords and locations (REST API)"},{"label":"Open Targets ENSG00000105675","url":"https://platform.opentargets.org/target/ENSG00000105675/associations","note":"association with cancer (MONDO_0004992) 0.58; per-cancer scores at or above 0.5: gastric cancer 0.56, non-Hodgkin lymphoma 0.52 (GraphQL API, CC0)"}],"hgnc":"HGNC:819","ensembl":"ENSG00000105675","uniprot":"P20648","entrez":"495","biology":"The catalytic subunit of the gastric H(+)/K(+) ATPase pump which transports H(+) ions in exchange for K(+) ions across the apical membrane of parietal cells. Uses ATP as an energy source to pump H(+) ions to the gastric lumen while transporting K(+) ion from the lumen into the cell. Remarkably generates a million-fold proton gradient across the gastric parietal cell membrane, acidifying the gastric juice down to pH 1. Within a transport cycle, the transfer of a H(+) ion across the membrane is coupled to ATP hydrolysis and is associated with a transient phosphorylation that shifts the pump conformation from inward-facing (E1) to outward-facing state (E2). The release of the H(+) ion in the stomach lumen is followed by binding of K(+) ion converting the pump conformation back to the E1 state. Location: Apical cell membrane (UniProt). Locus 19q13.12 (HGNC).","whereFound":["Gastric & gastro-oesophageal junction cancer: Open Targets association 0.56 with gastric cancer (MONDO_0001056)","Non-Hodgkin lymphoma: Open Targets association 0.52 with non-Hodgkin lymphoma (MONDO_0018908)"],"targetClass":"other","prevalence":[]},"route":"/targets/atp4a/","neighbours":{"collection":[{"id":"open-targets","kind":"collection","name":"Open Targets Platform","route":"/collections/open-targets/"}],"cancer":[{"id":"gastric","kind":"cancer","name":"Gastric & gastro-oesophageal junction cancer","route":"/cancers/gastric/"},{"id":"non-hodgkin-lymphoma","kind":"cancer","name":"Non-Hodgkin lymphoma (all types)","route":"/cancers/non-hodgkin-lymphoma/"}]}}