Protein phosphatase 1 catalytic subunit (PP1c)

The Protein phosphatase 1 catalytic subunit (PP1c) is a major eukaryotic serine/threonine phosphatase responsible for dephosphorylating a significant portion of phosphoserine and phosphothreonine residues in mammalian cells. While the free catalytic subunit lacks inherent substrate specificity, it achieves high selectivity in vivo by associating with over 200 different regulatory or targeting subunits to form distinct holoenzymes. These complexes allow PP1 to regulate a vast array of cellular processes, including glycogen metabolism, muscle contraction, cell cycle progression, and neuronal signaling. Dysregulation of PP1 activity is implicated in numerous pathologies, such as heart failure, where altered dephosphorylation of calcium-handling proteins occurs, and neurodegenerative diseases like Alzheimer's, characterized by tau hyperphosphorylation. In oncology, PP1 is involved in regulating cell survival and division pathways. While many natural toxins like okadaic acid act as potent inhibitors of the PP1 catalytic site, therapeutic development focuses on targeting specific PP1-regulatory subunit interactions to achieve precision and avoid the systemic toxicity associated with broad phosphatase inhibition.

Other names

PPP1CAPPP1CBPPP1CCProtein phosphatase 1 catalytic subunit alphaProtein phosphatase 1 catalytic subunit betaProtein phosphatase 1 catalytic subunit gammaPP-1Serine/threonine-protein phosphatase PP1-alpha catalytic subunitSerine/threonine-protein phosphatase PP1-beta catalytic subunitSerine/threonine-protein phosphatase PP1-gamma catalytic subunit

Inhibition of serine/threonine dephosphorylation by binding to the catalytic site or disrupting the formation of specific holoenzyme complexes.