Vasodilator-stimulated Phosphoprotein Activation of Serum-response Element-dependent Transcription Occurs Downstream of RhoA and Is Inhibited by cGMP-dependent Protein Kinase Phosphorylation

• Published in: The Journal of biological chemistry 2004-03, Vol.279 (11), p.10397-10407
• Main Authors: Zhuang, Shunhui, Nguyen, Giao T., Chen, Yongchang, Gudi, Tanima, Eigenthaler, Martin, Jarchau, Thomas, Walter, Ulrich, Boss, Gerry R., Pilz, Renate B.
• Format: Article
• Language: English
• Subjects: Actins - metabolism; Animals; Blotting, Western; Cell Adhesion Molecules - chemistry; Cell Adhesion Molecules - physiology; Cells, Cultured; Coloring Agents - pharmacology; Cyclic GMP-Dependent Protein Kinase Type I; Cyclic GMP-Dependent Protein Kinases - metabolism; Cyclic GMP-Dependent Protein Kinases - physiology; DNA - metabolism; Dose-Response Relationship, Drug; Fibroblasts - metabolism; Genes, Reporter; Genetic Vectors; GTP-Binding Proteins - metabolism; Humans; Microfilament Proteins; Mutation; Phalloidine - pharmacology; Phosphoproteins - chemistry; Phosphoproteins - physiology; Phosphorylation; Precipitin Tests; Protein Binding; Protein Structure, Tertiary; Rats; rhoA GTP-Binding Protein - metabolism; Serine - chemistry; Serum Response Element; Time Factors; Transcription, Genetic; Transfection; Vasodilator Agents - pharmacology
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M313048200

Vasodilator-stimulated phosphoprotein (VASP) associates with cytoskeletal structures and promotes F-actin formation. RhoA, a member of the Ras superfamily of proteins, activates serum response element (SRE)-dependent transcription through changes in actin dynamics. We now show that the F-actin binding region of VASP is required for VASP stimulation of SRE-dependent transcription, and that VASP is downstream of RhoA in stimulating SRE-dependent transcription. The isolated carboxyl-terminal coiled-coil region of VASP mediates protein tetramerization and has been used as a dominant negative form of VASP; we found that it forms complexes with endogenous VASP in vivo and inhibits in a dose-dependent fashion serum-, RhoA-, and VASP-stimulated SRE-dependent transcription. Cyclic GMP-dependent protein kinase (G-kinase) inhibits RhoA activation of SRE-dependent transcription (Gudi, T., Chen, J. C., Casteel, D. E., Seasholtz, T. M., Boss, G. R., and Pilz, R. B. (2002) J. Biol. Chem. 277, 37382-37393). We now show that the G-kinase inhibition that occurs downstream of RhoA can be explained, at least in part, by G-kinase phosphorylation of VASP on Ser239 at the carboxyl-terminal end of the G-actin binding site, with some contribution by phosphorylation of Ser157, which is proximal to the profilin binding site. A phosphorylation-deficient VASP mutant can partly prevent cGMP/G-kinase inhibition of serum- and RhoA-induced SRE-dependent transcription. These studies show that VASP, an important component of the cellular microfilament system, plays a major role in regulating SRE-dependent transcription, and that G-kinase regulates VASP activity.