Protein phosphatase magnesium-dependent 1D (PPM1D) (PPM1D)

Protein phosphatase magnesium-dependent 1D (PPM1D), commonly referred to as PP2Cδ or WIP1, is a member of the PP2C family of serine/threonine protein phosphatases that serves as a critical negative regulator of the DNA damage response (DDR) (UniProt: P49757). It is induced by p53 in response to stress and functions to return the cell to a homeostatic state by dephosphorylating key proteins such as p53, p38 MAPK, Chk1, and Chk2 (PubMed: 24901554). Overexpression or amplification of the PPM1D gene is observed in various malignancies, including breast and ovarian cancers, where it acts as an oncogene by suppressing tumor-suppressive pathways and promoting cell survival following DNA damage (PubMed: 21135154). Because of its role in dampening the DDR, PPM1D is a high-priority therapeutic target; inhibiting its activity can sensitize cancer cells to chemotherapy and radiotherapy (PubMed: 24901554). Several small-molecule inhibitors, most notably GSK2830371, have demonstrated the ability to selectively inhibit PPM1D and suppress tumor growth in preclinical models (PubMed: 24901554). However, therapeutic development must account for potential safety concerns, including the risk of disrupting normal DNA repair processes in healthy tissues. The target is also associated with Jansky-Diekmann-Vogt syndrome in rare genetic contexts, though its primary clinical interest remains in oncology (NCBI Gene: 8493). Targeting the catalytic domain of PP2Cδ allows for the restoration of p53-mediated apoptosis in p53-wildtype tumors. Current research focuses on improving the potency and pharmacokinetic properties of these inhibitors for clinical transition. Overall, PP2Cδ represents a strategic node for modulating the balance between cell cycle arrest and apoptosis in cancer therapy.

Other names

WIP1Wild-type p53-induced phosphatase 1PP2C-deltaProtein phosphatase 2C isoform deltaJDVS

Small molecule inhibition of the phosphatase catalytic activity to restore p53 and p38 MAPK signaling pathways.