TY - JOUR
T1 - Regulation of the association of adducin with actin filaments by Rho- associated kinase (Rho-kinase) and myosin phosphatase
AU - Kimura, Kazushi
AU - Fukata, Yuko
AU - Matsuoka, Yoichiro
AU - Bennett, Vann
AU - Matsuura, Yoshiharu
AU - Okawa, Katsuya
AU - Iwamatsu, Akihiro
AU - Kaibuchi, Kozo
PY - 1998/3/6
Y1 - 1998/3/6
N2 - 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 α-adducin in vitro and in vivo and that the phosphorylation of α-adducin by Rho-kinase enhanced the interaction of α-adducin with actin filaments in vitro. Myosin phosphatase composed of the catalytic subunit and MBS showed phosphatase activity toward α-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.
AB - 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 α-adducin in vitro and in vivo and that the phosphorylation of α-adducin by Rho-kinase enhanced the interaction of α-adducin with actin filaments in vitro. Myosin phosphatase composed of the catalytic subunit and MBS showed phosphatase activity toward α-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.
UR - http://www.scopus.com/inward/record.url?scp=0032489531&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0032489531&partnerID=8YFLogxK
U2 - 10.1074/jbc.273.10.5542
DO - 10.1074/jbc.273.10.5542
M3 - Article
C2 - 9488679
AN - SCOPUS:0032489531
SN - 0021-9258
VL - 273
SP - 5542
EP - 5548
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 10
ER -