Reactome: A Curated Pathway Database

Myosin phosphatase inactivation by ROCK

Stable Identifier
Homo sapiens
Locations in the PathwayBrowser

The activity of nonmuscle myosin II (NMM2) is suppressed by dephosphorylation of myosin regulatory light chains (MRLC), MYL9 and MYL12B, by the MLC phosphatase. The MLC phosphatase is composed of a catalytic subunit (PPP1CB) and two regulatory subunits, myosin phosphatase-targeting subunit 1 (MYPT1, PPP1R12A) and M20 (MYPT2, PPP1R12B). MYPT1 binds directly to myosin II. Myosin phosphatase is inhibited by ROCKs. ROCKs phosphorylate MYPT1 subunit of the myosin phosphatase at two inhibitory sites, Thr696 and Ser852, resulting in a decrease in MRLC phosphatase activity and an increase in phosphorylated MRLC (Kimura et al. 1996, Nakai et al. 1997, Katoh et al. 2001, Iwasaki et al. 2001), which promotes binding to filamentous actin and stress fibre formation. This effect is synergistic with the direct phosphorylation of MRLC by ROCKs.

Literature References
Participant Of
This entity is regulated by:
Title Physical Entity Activity
protein serine/threonine kinase activity of Activated ROCK:RhoA/B/C:GTP [plasma membrane] Activated ROCK:RhoA/B/C:GTP [plasma membrane] protein serine/threonine kinase activity (0004674)
Inferred From