Human cytomegalovirus-encoded G protein-coupled receptor US28 mediates smooth muscle cell migration through Galpha12.
Coupling of G proteins to ligand-engaged chemokine receptors is the paramount event in G-protein-coupled receptor signal transduction. Previously, we have demonstrated that the human cytomegalovirus-encoded chemokine receptor US28 mediates human vascular smooth muscle cell (SMC) migration in response to either RANTES or monocyte chemoattractant protein 1. In this report, we identify the G proteins that couple with US28 to promote vascular SMC migration and identify other signaling molecules that play critical roles in this process. US28-mediated cellular migration was enhanced with the expression of the G-protein subunits Galpha12 and Galpha13, suggesting that US28 may functionally couple to these G proteins. In correlation with this observation, US28 was able to activate RhoA, a downstream effector of Galpha12 and Galpha13 in cell types with these G proteins but not in those without them and activation of RhoA was dependent on US28 stimulation with RANTES. In addition, inactivation of RhoA or the RhoA-associated kinase p160ROCK with a dominant-negative mutant of RhoA or the small molecule inhibitor Y27632, respectively, abrogated US28-induced SMC migration. The data presented here suggest that US28 functionally signals through Galpha12 family G proteins and RhoA in a ligand-dependent manner and these signaling molecules are important for the ability of US28 to induce cellular migration.
Melnychuk
Ryan M
RM
Department of Molecular Microbiology and Immunology, Oregon Health Sciences University, Portland, OR 97201, USA.
Streblow
Daniel N
DN
Smith
Patricia P
PP
Hirsch
Alec J
AJ
Pancheva
Dora
D
Nelson
Jay A
JA
D000818:Animals; D019556:COS Cells; D002465:Cell Movement; D018946:Chemokine CCL5 / Q000494:pharmacology; D044365:GTP-Binding Protein alpha Subunits, G12-G13 / Q000502:physiology*; D006801:Humans; D009131:Muscle, Smooth, Vascular / Q000166:cytology*; D051381:Rats; D019707:Receptors, Chemokine / Q000502:physiology*; D015398:Signal Transduction; D014764:Viral Proteins / Q000502:physiology*; D020742:rhoA GTP-Binding Protein / Q000502:physiology
D018946:Chemokine CCL5; D019707:Receptors, Chemokine; C411191:US28 receptor, Cytomegalovirus; D014764:Viral Proteins; D044365:GTP-Binding Protein alpha Subunits, G12-G13; D020742:rhoA GTP-Binding Protein