Cofilin phosphorylation is elevated after F-actin disassembly induced by Rac1 depletion

TY - JOUR

T1 - Cofilin phosphorylation is elevated after F-actin disassembly induced by Rac1 depletion

AU - Liu, Linna

AU - Li, Jing

AU - Zhang, Liwang

AU - Zhang, Feng

AU - Zhang, Rong

AU - Chen, Xiang

AU - Brakebusch, Cord

AU - Wang, Zhipeng

AU - Liu, Xinyou

N1 - © 2015 International Union of Biochemistry and Molecular Biology.

PY - 2015/9/1

Y1 - 2015/9/1

N2 - Cytoskeletal reorganization is essential to keratinocyte function. Rac1 regulates cytoskeletal reorganization through signaling pathways such as the cofilin cascade. Cofilin severs actin filaments after activation by dephosphorylation. Rac1 was knocked out in mouse keratinocytes and it was found that actin filaments disassembled. In the epidermis of mice in which Rac1 was knocked out only in keratinocytes, cofilin phosphorylation was aberrantly elevated, corresponding to repression of the phosphatase slingshot1 (SSH1). These effects were independent of the signaling pathways for p21-activated kinase/LIM kinase (Pak/LIMK), protein kinase C, or protein kinase D or generation of reactive oxygen species. Similarly, when actin polymerization was specifically inhibited or Rac1 was knocked down, cofilin phosphorylation was enhanced and SSH1 was repressed. Repression of SSH1 partially blocked actin depolymerization induced by Rac1 depletion. Therefore, aberrant cofilin phosphorylation that induces actin polymerization might be a consequence of actin disassembly induced by the absence of Rac1.

AB - Cytoskeletal reorganization is essential to keratinocyte function. Rac1 regulates cytoskeletal reorganization through signaling pathways such as the cofilin cascade. Cofilin severs actin filaments after activation by dephosphorylation. Rac1 was knocked out in mouse keratinocytes and it was found that actin filaments disassembled. In the epidermis of mice in which Rac1 was knocked out only in keratinocytes, cofilin phosphorylation was aberrantly elevated, corresponding to repression of the phosphatase slingshot1 (SSH1). These effects were independent of the signaling pathways for p21-activated kinase/LIM kinase (Pak/LIMK), protein kinase C, or protein kinase D or generation of reactive oxygen species. Similarly, when actin polymerization was specifically inhibited or Rac1 was knocked down, cofilin phosphorylation was enhanced and SSH1 was repressed. Repression of SSH1 partially blocked actin depolymerization induced by Rac1 depletion. Therefore, aberrant cofilin phosphorylation that induces actin polymerization might be a consequence of actin disassembly induced by the absence of Rac1.

KW - Actin Depolymerizing Factors

KW - Actins

KW - Animals

KW - Cells, Cultured

KW - Keratinocytes

KW - Mice

KW - Phosphorylation

KW - Reactive Oxygen Species

KW - Signal Transduction

KW - rac1 GTP-Binding Protein

KW - Journal Article

KW - Research Support, Non-U.S. Gov't

U2 - 10.1002/biof.1235

DO - 10.1002/biof.1235

M3 - Journal article

C2 - 26496994

SN - 0951-6433

VL - 41

SP - 352

EP - 359

JO - BioFactors (Oxford, England)

JF - BioFactors (Oxford, England)

IS - 5

ER -