Human MutLα activates methylpurine DNA glycosylase to induce alkylation damage cytotoxicity.

MutLα enhances methylpurine DNA glycosylase activity, increasing alkylation damage cytotoxicity and revealing new targets for overcoming chemoresistance in tumors.

• Why it matters: Understanding how tumors develop resistance to alkylation chemotherapy is crucial for improving treatment efficacy, especially since loss of mismatch repair (MMR) is a common resistance mechanism.
• What they did: The study examined the interaction between MutLα and the BER enzyme MPG through biochemical reconstitution and cellular assays, focusing on how MutLα activates MPG to promote alkylation damage.
• The result: MutLα stimulates MPG activity, leading to increased formation of cytotoxic abasic sites, which enhances cell death from alkylating agents like MMS, offering new insights into overcoming chemoresistance.