Regulation of the association of adducin with actin filaments by Rho-associated kinase (Rho-kinase) and myosin phosphatase.

Journal Article

The small GTPase Rho is believed to regulate the actin cytoskeleton and cell adhesion through its specific targets. We previously identified the Rho targets: protein kinase N, Rho-associated kinase (Rho-kinase), and the myosin-binding subunit (MBS) of myosin phosphatase. Here we purified MBS-interacting proteins, identified them as adducin, and found that MBS specifically interacted with adducin in vitro and in vivo. Adducin is a membrane-skeletal protein that promotes the binding of spectrin to actin filaments and is concentrated at the cell-cell contact sites in epithelial cells. We also found that Rho-kinase phosphorylated alpha-adducin in vitro and in vivo and that the phosphorylation of alpha-adducin by Rho-kinase enhanced the interaction of alpha-adducin with actin filaments in vitro. Myosin phosphatase composed of the catalytic subunit and MBS showed phosphatase activity toward alpha-adducin, which was phosphorylated by Rho-kinase. This phosphatase activity was inhibited by the phosphorylation of MBS by Rho-kinase. These results suggest that Rho-kinase and myosin phosphatase regulate the phosphorylation state of adducin downstream of Rho and that the increased phosphorylation of adducin by Rho-kinase causes the interaction of adducin with actin filaments.

Full Text

Duke Authors

Cited Authors

  • Kimura, K; Fukata, Y; Matsuoka, Y; Bennett, V; Matsuura, Y; Okawa, K; Iwamatsu, A; Kaibuchi, K

Published Date

  • March 6, 1998

Published In

Volume / Issue

  • 273 / 10

Start / End Page

  • 5542 - 5548

PubMed ID

  • 9488679

International Standard Serial Number (ISSN)

  • 0021-9258

Language

  • eng

Conference Location

  • United States