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  • The EMBO Journal (2003) 22, 3050 - 3061
  • doi:10.1093/emboj/cdg287

A role for VASP in RhoA-Diaphanous signalling to actin dynamics and SRF activity

Robert Grosse1, John W. Copeland1, Timothy P. Newsome2, Michael Way2 and Richard Treisman1

  1. Cancer Research UK, London Research Institute, Lincoln's Inn Fields Laboratories, Transcription Laboratory, Room 401, 44 Lincoln's Inn Fields, London WC2A 3PX, UK
  2. Cancer Research UK, London Research Institute, Lincoln's Inn Fields Laboratories, Cell Motility Laboratory, Room 529, 44 Lincoln's Inn Fields, London WC2A 3PX, UK

Correspondence to:

Richard Treisman, E-mail: richard.treisman@cancer.org.uk

Received 5 November 2002; Accepted 17 April 2003; Revised 14 April 2003

Vasodilator-stimulated phosphoprotein (VASP) is involved in multiple actin-mediated processes, including regulation of serum response factor (SRF) activity. We used the SRF transcriptional assay to define functional domains in VASP and to show that they coincide with those required for F-actin accumulation, as determined by a quantitative FACS assay. We identified inactive VASP mutants that can interfere both with F-actin assembly and with SRF activation by wild-type VASP. These VASP mutants also inhibit actin-based motility of Vaccinia virus and Shigella flexneri. VASP-induced F-actin accumulation and SRF activation require both functional Rho and its effector mDia, and conversely, mDia-mediated SRF activation is critically dependent on functional VASP. VASP and mDia also associate physically in vivo. These findings show that VASP and mDia function cooperatively downstream of Rho to control F-actin assembly and SRF activity.

  • Keywords:

    • mDia1,
    • RhoA,
    • signal transduction,
    • SRF,
    • VASP