Phosphorylation of vimentin by Rho-associated kinase at a unique amino-terminal site that is specifically phosphorylated during cytokinesis

J Biol Chem. 1998 May 8;273(19):11728-36. doi: 10.1074/jbc.273.19.11728.

Abstract

We found that vimentin, the most widely expressed intermediate filament protein, served as an excellent substrate for Rho-associated kinase (Rho-kinase) and that vimentin phosphorylated by Rho-kinase lost its ability to form filaments in vitro. Two amino-terminal sites on vimentin, Ser38 and Ser71, were identified as the major phosphorylation sites for Rho-kinase, and Ser71 was the most favored and unique phosphorylation site for Rho-kinase in vitro. To analyze the vimentin phosphorylation by Rho-kinase in vivo, we prepared an antibody GK71 that specifically recognizes the phosphorylation of vimentin-Ser71. Ectopic expression of constitutively active Rho-kinase in COS-7 cells induced phosphorylation of vimentin at Ser71, followed by the reorganization of vimentin filament networks. During the cell cycle, the phosphorylation of vimentin-Ser71 occurred only at the cleavage furrow in late mitotic cells but not in interphase or early mitotic cells. This cleavage furrow-specific phosphorylation of vimentin-Ser71 was observed in the various types of cells we examined. All these accumulating observations increase the possibility that Rho-kinase may have a definite role in governing regulatory processes in assembly-disassembly and turnover of vimentin filaments at the cleavage furrow during cytokinesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Anaphase
  • Animals
  • COS Cells
  • Cattle
  • Cell Division*
  • Fluorescent Antibody Technique, Indirect
  • GTP-Binding Proteins / metabolism
  • Guanosine Triphosphate / metabolism
  • Immunologic Techniques
  • Intermediate Filaments / ultrastructure
  • Intracellular Signaling Peptides and Proteins
  • Microscopy, Confocal
  • Molecular Sequence Data
  • Phosphorylation
  • Phosphoserine / metabolism
  • Protein-Serine-Threonine Kinases / metabolism*
  • Vimentin / metabolism*
  • rho GTP-Binding Proteins
  • rho-Associated Kinases

Substances

  • Intracellular Signaling Peptides and Proteins
  • Vimentin
  • Phosphoserine
  • Guanosine Triphosphate
  • Protein-Serine-Threonine Kinases
  • rho-Associated Kinases
  • GTP-Binding Proteins
  • rho GTP-Binding Proteins