ABSTRACT
Objective To study the effect of human G-coupled protein kinase 4(GRK4) A142V overexpression on angiotensin Ⅱ1 type(AT1 ) receptor and its-mediated proliferation of rat vascular smooth muscle cells .Methods We constructed a lentiviral vec-tor carrying human GRK4-EGFP gene and observed its expression in A10 cells .Expression of AT1 receptor were determined by im-munoblotting ,GRK4 activity were checked by spectrophotometry ;the linkage between GRK4 and AT1 receptor were determined by co-immunoprecipitation .[3 H] thymidine incorporation was used to detect changes of cell proliferation .Results As compared with the control cells ,A142V-transfected cells had higher GRK4 activity and higher AT1 receptor expression ;there was linkage between GRK4 and AT1 receptor ,the co-immunoprecipitation levels were lower in A142V cells .The basal levels of VSMC proliferation was higher in A142V cells ,Ang Ⅱ increased VSMC proliferation to a greater extent in A 142V cells .Conclusion GRK4 A142V ,via in-creasing GRK4 activity ,increases AT1 receptor expression and function in vascular smooth muscle cell proliferation .