论文部分内容阅读
To investigate how F261S mutation identified from Chinese obese patients affects the function of melanocortin 4 receptor (MC4R) and to analyze the obesity-related phenotypes in subjects carrying the F261S mutation. Methods F261S mutant of MC4R was generated by site-directed mutagenesis. Plasmids encoding wild-type or F261S mutant of MC4R were transfected into HEK293 and COS-7 cells to examine their functional characteristics. Signaling properties of F261S MC4R were assessed by measuring intracellular cAMP levels in response to α-MSH stimulation. Cell surface expression of F261S MC4R was compared with that of wild-type MC4R. Clinical examinations were performed in subjects carrying F261S mutation and in non-mutated controls. Results The α-MSH-stimulated reporter gene activity was significantly reduced in cells expressing F261S MC4R, with a maximal response equal to 57% of wild-type MC4R. The F261S mutation also led to a significant change in the EC value compared with the wild-type receptor (P