title: Heterodimerization of human apelin and bradykinin 1 receptors: novel signal transduction characteristics.
abstract: Apelin receptor (APJ) and bradykinin 1 receptor (B1R) are involved in a variety of important physiological processes, which share many similar characteristics in distribution and functions in the cardiovascular system. This study explored the possibility of heterodimerization between APJ and B1R, and investigated the impact of heterodimer on the signal transduction characteristics and the physiological functions in human endothelial cells after stimulation with their agonists. We first identified the endogenous expression of APJ and B1R in HUVECs and their co-localization on HEK293 membrane. The constitutive heterodimerization between the APJ and B1R was then demonstrated by BRET and FRET assays. Stimulation with Apelin-13 and des -Arg(9)-BK enhanced the phosphorylation of eNOS in HUVECs, which could be dampened by the knockdown of APJ or B1R, indicating the co-existence of APJ and B1R is critical for eNOS phosphorylation in HUVECs. Furthermore, APJ/B1R heterodimers were found to enhance the activity of PKC signaling pathway and increase intracellular Ca(2+) concentration in HEK293 cells, which might be the mechanism of APJ/B1R heterodimers promoting the phosphorylation of eNOS and leads to increased Gαq, PKC signal pathway activities and a significant increase in cell proliferation. The results provide a new theoretical and experimental base for revealed intracellular molecular mechanisms of physiological function involved in the APJ and B1R and provide potential new targets for the development of drugs and treating cardiovascular disease.
authors.affiliation: Neurobiology Institute, Jining Medical University, Jining, Shandong, PR China.
authors.forename: Bo
authors.initials: B
authors.lastname: Bai
authors.affiliation: Neurobiology Institute, Jining Medical University, Jining, Shandong, PR China.
authors.forename: Lulu
authors.initials: L
authors.lastname: Liu
authors.affiliation: Neurobiology Institute, Jining Medical University, Jining, Shandong, PR China.
authors.forename: Ning
authors.initials: N
authors.lastname: Zhang
authors.affiliation: Neurobiology Institute, Jining Medical University, Jining, Shandong, PR China.
authors.forename: Chunmei
authors.initials: C
authors.lastname: Wang
authors.affiliation: Neurobiology Institute, Jining Medical University, Jining, Shandong, PR China.
authors.forename: Yunlu
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: Neurobiology Institute, Jining Medical University, Jining, Shandong, PR China; Division of Metabolic and Vascular Health, Warwick Medical School, University of Warwick, Coventry, UK. Electronic address: Jing.Chen@warwick.ac.uk.
authors.forename: Jing
authors.initials: J
authors.lastname: Chen
mesh_terms: D000073861:Apelin; D000075244:Apelin Receptors; D001920:Bradykinin / Q000031:analogs & derivatives / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling; D002320:Cardiovascular Physiological Phenomena; D002319:Cardiovascular System; D002460:Cell Line; D049109:Cell Proliferation; D004789:Enzyme Activation / Q000187:drug effects; D043802:GTP-Binding Protein alpha Subunits, Gq-G11 / Q000096:biosynthesis; D057809:HEK293 Cells; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D019426:Integrases / Q000096:biosynthesis; D036341:Intercellular Signaling Peptides and Proteins / Q000494:pharmacology; D050778:NFATC Transcription Factors / Q000096:biosynthesis; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism*; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism; D034622:RNA Interference; D034741:RNA, Small Interfering; D043783:Receptor, Bradykinin B1 / Q000096:biosynthesis / Q000235:genetics*; D043562:Receptors, G-Protein-Coupled / Q000096:biosynthesis / Q000235:genetics*
chemical_list: C115436:APLN protein, human; C104575:APLNR protein, human; D000073861:Apelin; D000075244:Apelin Receptors; D036341:Intercellular Signaling Peptides and Proteins; D050778:NFATC Transcription Factors; D034741:RNA, Small Interfering; D043783:Receptor, Bradykinin B1; D043562:Receptors, G-Protein-Coupled; C024626:bradykinin, des-Arg(9)-; D052250:Nitric Oxide Synthase Type III; D011493:Protein Kinase C; C045073:Cre recombinase; D019426:Integrases; D043802:GTP-Binding Protein alpha Subunits, Gq-G11; D001920:Bradykinin; D002118:Calcium
keywords: Apelin receptor; Bradykinin 1 receptor; G protein-coupled receptors; Heterodimer; Resonance energy transfer