The essential role of profilin in the assembly of actin for microspike formation.
Profilin was first identified as an actin monomer binding protein; however, recent reports indicate its involvement in actin polymerization. To date, there is no direct evidence of a functional role in vivo for profilin in actin cytoskeletal reorganization. Here, we prepared a profilin mutant (H119E) defective in actin binding, but ... retaining the ability to bind to other proteins. This mutant profilin I suppresses actin polymerization in microspike formation induced by N-WASP, the essential factor in microspike formation. Profilin associates both in vivo and in vitro with N-WASP at proline-rich sites different from those to which Ash/Grb2 binds. This association between profilin and N-WASP is required for N-WASP-induced efficient microspike elongation. Moreover, we succeeded in reconstituting microspike formation in permeabilized cells using profilin I combined with N-WASP and its regulator, Cdc42. These findings provide the first evidence that profilin is a key molecule linking a signaling network to rapid actin polymerization in microspike formation.
Mesh Terms:
3T3 Cells, Actins, Amino Acid Sequence, Animals, Binding Sites, COS Cells, Contractile Proteins, Gene Expression Regulation, Mice, Microfilament Proteins, Molecular Sequence Data, Mutagenesis, Site-Directed, Nerve Tissue Proteins, Neurites, Profilins, Protein Binding, Wiskott-Aldrich Syndrome Protein, Neuronal
3T3 Cells, Actins, Amino Acid Sequence, Animals, Binding Sites, COS Cells, Contractile Proteins, Gene Expression Regulation, Mice, Microfilament Proteins, Molecular Sequence Data, Mutagenesis, Site-Directed, Nerve Tissue Proteins, Neurites, Profilins, Protein Binding, Wiskott-Aldrich Syndrome Protein, Neuronal
EMBO J.
Date: Nov. 16, 1998
PubMed ID: 9822597
View in: Pubmed Google Scholar
Download Curated Data For This Publication
6496
Switch View:
- Interactions 2