p140mDia, a mammalian homolog of Drosophila diaphanous, is a target protein for Rho small GTPase and is a ligand for profilin

EMBO J. 1997 Jun 2;16(11):3044-56. doi: 10.1093/emboj/16.11.3044.


Rho small GTPase regulates cell morphology, adhesion and cytokinesis through the actin cytoskeleton. We have identified a protein, p140mDia, as a downstream effector of Rho. It is a mammalian homolog of Drosophila diaphanous, a protein required for cytokinesis, and belongs to a family of formin-related proteins containing repetitive polyproline stretches. p140mDia binds selectively to the GTP-bound form of Rho and also binds to profilin. p140mDia, profilin and RhoA are co-localized in the spreading lamellae of cultured fibroblasts. They are also co-localized in membrane ruffles of phorbol ester-stimulated sMDCK2 cells, which extend these structures in a Rho-dependent manner. The three proteins are recruited around phagocytic cups induced by fibronectin-coated beads. Their recruitment is not induced after Rho is inactivated by microinjection of botulinum C3 exoenzyme. Overexpression of p140mDia in COS-7 cells induced homogeneous actin filament formation. These results suggest that Rho regulates actin polymerization by targeting profilin via p140mDia beneath the specific plasma membranes.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3T3 Cells
  • Amino Acid Sequence
  • Animals
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Cell Adhesion
  • Cell Membrane / metabolism*
  • Cell Movement
  • Contractile Proteins*
  • Drosophila / genetics
  • Drosophila Proteins*
  • Fluorescent Antibody Technique
  • Formins
  • Fungal Proteins / genetics
  • GTP-Binding Proteins / metabolism*
  • Insect Proteins / genetics
  • Ligands
  • Mice
  • Microfilament Proteins / metabolism*
  • Molecular Sequence Data
  • Profilins
  • Protein Binding
  • Recombinant Proteins / metabolism
  • Saccharomyces cerevisiae Proteins*
  • Sequence Homology, Amino Acid
  • rhoA GTP-Binding Protein


  • Bni1 protein, S cerevisiae
  • Carrier Proteins
  • Contractile Proteins
  • Diap1 protein, mouse
  • Drosophila Proteins
  • Formins
  • Fungal Proteins
  • Insect Proteins
  • Ligands
  • Microfilament Proteins
  • Pfn1 protein, mouse
  • Profilins
  • Recombinant Proteins
  • Saccharomyces cerevisiae Proteins
  • diaphanous protein, Drosophila
  • GTP-Binding Proteins
  • rhoA GTP-Binding Protein

Associated data

  • GENBANK/L31766
  • GENBANK/U11288
  • GENBANK/U34258
  • GENBANK/U96963
  • GENBANK/X62379