Vasodilator-stimulated phosphoprotein activation of serum-response element-dependent transcription occurs downstream of RhoA and is inhibited by cGMP-dependent protein kinase phosphorylation.
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 Ser(239) at the carboxyl-terminal end of the G-actin binding site, with some contribution by phosphorylation of Ser(157), 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.
Zhuang
Shunhui
S
Department of Medicine and Cancer Center, University of California, San Diego, La Jolla 92093-0652, USA.
Nguyen
Giao T
GT
Chen
Yongchang
Y
Gudi
Tanima
T
Eigenthaler
Martin
M
Jarchau
Thomas
T
Walter
Ulrich
U
Boss
Gerry R
GR
Pilz
Renate B
RB
D000199:Actins / Q000378:metabolism; D000818:Animals; D015153:Blotting, Western; D015815:Cell Adhesion Molecules / Q000737:chemistry* / Q000502:physiology; D002478:Cells, Cultured; D004396:Coloring Agents / Q000494:pharmacology; D062965:Cyclic GMP-Dependent Protein Kinase Type I; D017869:Cyclic GMP-Dependent Protein Kinases / Q000378:metabolism* / Q000502:physiology*; D004247:DNA / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005347:Fibroblasts / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000378:metabolism; D017930:Genes, Reporter; D005822:Genetic Vectors; D006801:Humans; D008840:Microfilament Proteins; D009154:Mutation; D010590:Phalloidine / Q000494:pharmacology; D010750:Phosphoproteins / Q000737:chemistry* / Q000502:physiology; D010766:Phosphorylation; D011233:Precipitin Tests; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D051381:Rats; D012694:Serine / Q000737:chemistry; D027602:Serum Response Element; D013997:Time Factors; D014158:Transcription, Genetic; D014162:Transfection; D014665:Vasodilator Agents / Q000494:pharmacology*; D020742:rhoA GTP-Binding Protein / Q000378:metabolism*; D000098662:Vasodilator-Stimulated Phosphoprotein
D000199:Actins; D015815:Cell Adhesion Molecules; D004396:Coloring Agents; D008840:Microfilament Proteins; D010750:Phosphoproteins; D014665:Vasodilator Agents; D000098662:Vasodilator-Stimulated Phosphoprotein; D010590:Phalloidine; D012694:Serine; D004247:DNA; D062965:Cyclic GMP-Dependent Protein Kinase Type I; D017869:Cyclic GMP-Dependent Protein Kinases; C569718:PRKG1 protein, human; D019204:GTP-Binding Proteins; D020742:rhoA GTP-Binding Protein