cAMP-dependent Protein Kinase Phosphorylation of EVL, a Mena/VASP Relative, Regulates Its Interaction with Actin and SH3 Domains
| Autor: | Frank B. Gertler, Christophe Ampe, Anja Lambrechts, Adam V. Kwiatkowski, Lorene M. Lanier, Joël Vandekerckhove, James E. Bear |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
CD4-Positive T-Lymphocytes
Proline Molecular Sequence Data Fluorescent Antibody Technique macromolecular substances Lymphocyte Activation Transfection Binding Competitive Biochemistry src Homology Domains WW domain Mice Profilins Biopolymers Contractile Proteins Animals Amino Acid Sequence Platelet activation Phosphorylation Protein kinase A Molecular Biology Cells Cultured biology Microfilament Proteins Proteins Ena/Vasp homology proteins Actin remodeling Cell Biology Fibroblasts Phosphoproteins Cyclic AMP-Dependent Protein Kinases Actins Rats Cell biology Cytoskeletal Proteins Profilin biology.protein Lamellipodium Carrier Proteins Cell Adhesion Molecules Protein Binding |
| Zdroj: | Journal of Biological Chemistry. 275:36143-36151 |
| ISSN: | 0021-9258 |
| Popis: | Proteins of the Ena/VASP family are implicated in processes that require dynamic actin remodeling such as axon guidance and platelet activation. In this work, we explored some of the pathways that likely regulate actin dynamics in part via EVL (Ena/VASP-like protein). Two isoforms, EVL and EVL-I, were highly expressed in hematopoietic cells of thymus and spleen. In CD3-activated T-cells, EVL was found in F-actin-rich patches and at the distal tips of the microspikes that formed on the activated side of the T-cells. Like the other family members, EVL localized to focal adhesions and the leading edge of lamellipodia when expressed in fibroblasts. EVL was a substrate for the cAMP-dependent protein kinase, and this phosphorylation regulated several of the interactions between EVL and its ligands. Unlike VASP, EVL nucleated actin polymerization under physiological conditions, whereas phosphorylation of both EVL and VASP decreased their nucleating activity. EVL bound directly to the Abl, Lyn, and nSrc SH3 domains; the FE65 WW domain; and profilin, likely via its proline-rich core. Binding of Abl and nSrc SH3 domains, but not profilin or other SH3 domains, was abolished by cAMP-dependent protein kinase phosphorylation of EVL. We show strong cooperative binding of two profilin dimers on the polyproline sequence of EVL. Additionally, profilin competed with the SH3 domains for binding to partially overlapping binding sites. These data suggest that the function of EVL could be modulated in a complex manner by its interactions with multiple ligands and through phosphorylation by cyclic nucleotide dependent kinases. |
| Databáze: | OpenAIRE |
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