Myosin phosphatase target subunit 1 (MYPT1)

Myosin phosphatase target subunit 1 (MYPT1) is a large regulatory subunit of myosin phosphatase, a heterotrimeric enzyme complex crucial for dephosphorylating myosin II regulatory light chains. MYPT1 confers substrate specificity by binding both the catalytic subunit of protein phosphatase 1C (PP1C, especially the δ isoform) and myosin, thereby modulating the contractility and relaxation of smooth muscle as well as other cellular processes such as migration and division[1][4][6]. MYPT1 contains various regulatory domains and sites for phosphorylation, which mediate its activity; it is a nodal point for signaling pathways (e.g., RhoA/Rho-kinase), making it relevant in the pathophysiology of hypertension, vascular disorders, and cell motility-related diseases[4][5]. Although there are currently no approved therapeutic agents that specifically target MYPT1, it is viewed as a potential drug target, especially in the context of smooth muscle hypercontractility and certain malignancies where MYPT1 signaling is disrupted[4][5][6].

Other names

Myosin-binding subunit of myosin phosphatasePPP1R12AMyosin phosphatase targeting subunit 1

Drugs/potential drugs may act by modulating MYPT1 phosphorylation, thereby regulating myosin phosphatase activity (e.g., Rho-kinase inhibitors increase MYPT1-mediated phosphatase activity, causing smooth muscle relaxation)