PAK1 and aPKCζ Regulate Myosin II-B Phosphorylation: A Novel Signaling Pathway Regulating Filament Assembly

Publisher Website
Google Scholar
Abstract
Many signaling pathways regulate the function of the cellular cytoskeleton. Yet we know very little about the proteins involved in the cross-talk between the signaling and the cytoskeletal systems. Here we show that myosin II-B, an important cytoskeletal protein, resides in a complex with p21-activated kinase 1 (PAK1) and atypical protein kinase C (PKC) zeta (aPKCzeta) and that the interaction between these proteins is EGF-dependent. We further show that PAK1 is involved in aPKCzeta phosphorylation and that aPKCzeta phosphorylates myosin II-B directly on a specific serine residue in an EGF-dependent manner. This latter phosphorylation is specific to isoform B of myosin II, and it leads to slower filament assembly of myosin II-B. Furthermore, a decrease in aPKCzeta expression in the cells alters myosin II-B cellular organization. Our finding of a new signaling pathway involving PAK1, aPKCzeta, and myosin II-B, which is implicated in myosin II-B filament assembly and cellular organization, provides an important link between the signaling system and cytoskeletal dynamics.

This publication has 53 references indexed in Scilit: