Protein phosphatase magnesium-dependent 1D (PPM1D)

Protein phosphatase magnesium-dependent 1D (PPM1D), frequently referred to as WIP1, is a member of the PP2C family of serine/threonine phosphatases that serves as a critical negative regulator of the cellular stress response. It primarily functions by dephosphorylating and inactivating key proteins involved in the DNA damage response (DDR) and cell cycle checkpoints, such as p53, p38 MAPK, Chk1, and Chk2 [1, 3]. While this activity is essential for returning cells to a homeostatic state following successful DNA repair, the overexpression or amplification of PPM1D is a common feature in various malignancies, including breast, ovarian, and brain cancers [3, 4]. In these contexts, PPM1D acts as an oncogene by suppressing tumor-suppressive signaling, thereby facilitating uncontrolled cell proliferation and survival. Therapeutic strategies targeting PPM1D involve the use of small-molecule inhibitors, such as GSK2830371, which aim to restore the sensitivity of cancer cells to apoptosis and DNA-damaging agents [2]. Beyond its role in solid tumors, PPM1D has also been implicated in clonal hematopoiesis, where specific mutations can provide a selective advantage to hematopoietic stem cells under the pressure of chemotherapy [1, 4].

Other names

WIP1Wild-type p53-induced phosphatase 1Protein phosphatase 2C deltaPP2C-deltaProtein phosphatase 1D

Small molecule inhibition of the PPM1D phosphatase catalytic activity to prevent the dephosphorylation of substrates such as p53 and p38 MAPK, thereby restoring tumor-suppressive signaling and promoting apoptosis in cancer cells [2, 3].