OncoSignal
Live from Open Targets Platform, fetched 2026-11-11 16:03 UTC. Every row links to its source record.

MLH1 mutL homolog 1

ENSG00000076242 · protein coding · Open Targets profile

Heterodimerizes with PMS2 to form MutL alpha, a component of the post-replicative DNA mismatch repair system (MMR). DNA repair is initiated by MutS alpha (MSH2-MSH6) or MutS beta (MSH2-MSH3) binding to a dsDNA mismatch, then MutL alpha is recruited to the heteroduplex. Assembly of the MutL-MutS-heteroduplex ternary complex in presence of RFC and PCNA is sufficient to activate endonuclease activity of PMS2. It introduces single-strand breaks near the mismatch and thus generates new entry points for the exonuclease EXO1 to degrade the strand containing the mismatch. DNA methylation would prevent cleavage and therefore assure that only the newly mutated DNA strand is going to be corrected. MutL alpha (MLH1-PMS2) interacts physically with the clamp loader subunits of DNA polymerase III, suggesting that it may play a role to recruit the DNA polymerase III to the site of the MMR. Also implicated in DNA damage signaling, a process which induces cell cycle arrest and can lead to apoptosis in case of major DNA damages. Heterodimerizes with MLH3 to form MutL gamma which plays a role in meiosis. {ECO:0000269|PubMed:16873062, ECO:0000269|PubMed:18206974, ECO:0000269|PubMed:20020535, ECO:0000269|PubMed:21120944, ECO:0000269|PubMed:39032648, ECO:0000269|PubMed:9311737}.

In 12 of 15 cancers, the evidence for MLH1 comes mainly from inherited variants

Each row is a cancer, strongest overall evidence first. The two dots show how strong the inherited (germline) and tumour-mutation (somatic) evidence is; the line between them is the gap.

Inherited (germline) variantsMutations in tumours (somatic)
00.250.50.751Lynch syndromeLynch syndromeLynch syndrome: somatic 0.95Lynch syndrome: germline 0.90colorectal cancercolorectal cancercolorectal cancer: germline 0.89mismatch repair cancer syndrome 1mismatch repair cancer syndrome 1mismatch repair cancer syndrome 1: germline 0.88Muir-Torre syndromeMuir-Torre syndromeMuir-Torre syndrome: germline 0.91colon carcinomacolon carcinomacolon carcinoma: somatic 0.30colon carcinoma: germline 0.95malignant colon neoplasmmalignant colon neoplasmmalignant colon neoplasm: germline 0.91mismatch repair cancer syndromemismatch repair cancer syndromemismatch repair cancer syndrome: germline 0.61hereditary nonpolyposis colon cancerhereditary nonpolyposis colon cancerhereditary nonpolyposis colon cancer: germline 0.91colonic neoplasmcolonic neoplasmcolonic neoplasm: germline 0.88endometrial carcinomaendometrial carcinomaendometrial carcinoma: somatic 0.46endometrial carcinoma: germline 0.84Non-polyposis Turcot syndromeNon-polyposis Turcot syndromehereditary neoplastic syndromehereditary neoplastic syndromehereditary neoplastic syndrome: germline 0.95hereditary nonpolyposis colorectal carc…hereditary nonpolyposis colorectal carcinomahereditary nonpolyposis colorectal carcinoma: germline 0.94gastric cancergastric cancergastric cancer: germline 0.85ovarian carcinomaovarian carcinomaovarian carcinoma: somatic 0.46

Scores run from 0 (no evidence) to 1 (strongest). A missing dot at 0 means Open Targets holds no evidence of that kind. Source: Open Targets Platform, fetched live.

Tractability

Small molecule
Structure with Ligand, Med-Quality Pocket
PROTAC
UniProt Ubiquitination, Database Ubiquitination, Half-life Data

gnomAD loss of function constraint: o/e 0.4015499949455261 (upper bound 0.5282599925994873). Low values mean loss of function is poorly tolerated, a safety flag for inhibition.

Who runs trials of these drugs

No named investigators on registry trials of MLH1's approved or late-stage drugs in the last three years.

No terminated, withdrawn or suspended trials of MLH1's drugs are registered

All 0 drugs and clinical candidates as a table

Each drug, stage and indication links to its Open Targets record, where the trials and approvals behind it are listed. Salt forms (for example a mesylate) are listed as Open Targets records them, as separate entries.

DrugTypeHighest stageIndicationsSource records
No drugs or clinical candidates recorded.