Phosphatase and actin regulator 4 (PHACTR4)

Phosphatase and actin regulator 4 (PHACTR4) is a member of the Phactr family of proteins, which bind both protein phosphatase 1 (PP1) and actin[1][4][5]. PHACTR4 regulates PP1 activity and cytoskeletal dynamics by interacting with actin and targeting PP1 towards specific substrates, thereby modulating cellular functions including neural tube closure, cell migration, and proliferation[1][5][6]. PHACTR4 acts as a tumor suppressor by restraining normal cell proliferation and transformation, in part through regulation of the Rb pathway and dephosphorylation of PP1 substrates; its loss through mutation or deletion is observed in multiple human cancers[6][7]. Beyond cancer, it is essential for neural development; mutations can cause neurodevelopmental defects such as neural tube and optic fissure closure anomalies[5][7]. PHACTR4 also binds intermediate filament proteins in neural cells and its activity is modulated by protein phosphorylation[3]. No drugs directly targeting PHACTR4 are currently known, and there are no established drug mechanisms, biomarkers, or specific safety liabilities documented beyond its essential developmental and tumor suppressor roles[5][6][7].

Other names

PPP1R124PRO2963FLJ13171Phactr4protein phosphatase 1 regulatory subunit 124PHAR4_HUMAN