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A nuclear MAL-function links Rho to SRF

Jeffrey Settleman1

  • 1Massachusetts General Hospital Cancer Center and Harvard Medical School, 149 13th Street, Charlestown, MA 02129, USA.

Molecular Cell
|May 29, 2003
PubMed

Insights

The transcription factor MAL binds actin monomers, acting as a coactivator for Serum Response Factor (SRF). Its movement to the nucleus requires MAL to detach from actin, regulating SRF-mediated transcription.

Area of Science:

  • Cell biology
  • Molecular biology
  • Transcription regulation

Background:

  • Serum Response Factor (SRF) activation is linked to Rho GTPase-induced actin assembly.
  • SRF's ability to sense changes in cellular actin monomer levels is crucial for transcription.
  • The precise mechanism of SRF activation sensing remained unclear.

Purpose of the Study:

  • To identify proteins involved in SRF-mediated transcription.
  • To elucidate the role of actin dynamics in regulating SRF activity.
  • To characterize the function of the transcription factor MAL in the SRF pathway.

Main Methods:

  • Protein-protein interaction studies to identify actin-binding proteins.
  • Cellular localization assays to track MAL translocation.
  • Biochemical assays to study MAL-actin interactions and SRF coactivation.

Main Results:

  • The transcription factor MAL was identified as an actin-binding protein.
  • MAL functions as a coactivator for SRF.
  • MAL's translocation from the cytoplasm to the nucleus is dependent on its dissociation from actin monomers.

Conclusions:

  • MAL acts as a critical link between actin dynamics and SRF-mediated transcription.
  • Actin monomer levels regulate SRF activity through MAL.
  • This finding provides a molecular mechanism for how SRF senses changes in the actin cytoskeleton.

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