The 70 kDa S6 kinase complexes with and is activated by the Rho family G proteins Cdc42 and Rac1. Academic Article uri icon

Overview

abstract

  • The 70 kDa ribosomol S6 kinase (pp70S6k) plays an important role in the progression of cells through G1 phase of the cell cycle. However, little is known of the signaling molecules that mediate its activation. We demonstrate that Rho family G proteins regulate pp70S6k activity in vivo. Activated alleles of Cdc42 and Rac1, but not RhoA, stimulate pp70S6k activity in multiple cell types. Activation requires an intact effector domain and isoprenylation of Cdc42 and Rac1. Coexpression of Dbl, an exchange factor for Cdc42, also activates pp70S6k. Growth factor-induced activation of pp70S6k is abrogated by dominant negative alleles of Cdc42 and Rac1. In addition, Cdc42 and Rac1 form GTP-dependent complex with the catalytically inactive form of pp70S6k in vitro and in vivo, suggesting a mechanism by which these G proteins activate pp70S6k.

publication date

  • May 17, 1996

Research

keywords

  • Bacterial Toxins
  • Cell Cycle Proteins
  • Escherichia coli Proteins
  • GTP-Binding Proteins
  • Membrane Proteins
  • Mitogen-Activated Protein Kinases
  • Protein Serine-Threonine Kinases

Identity

Scopus Document Identifier

  • 0029890229

Digital Object Identifier (DOI)

  • 10.1016/s0092-8674(00)81257-x

PubMed ID

  • 8653792

Additional Document Info

volume

  • 85

issue

  • 4