title: Novel signaling of dynorphin at κ-opioid receptor/bradykinin B2 receptor heterodimers.
abstract: The κ-opioid receptor (KOR) and bradykinin B2 receptor (B2R) are involved in a variety of important physiological processes and share many similar characteristics in terms of their distribution and functions in the nervous system. We first demonstrated the endogenous expression of KOR and B2R in human SH-SY5Y cells and their co-localization on the membrane of human embryonic kidney 293 (HEK293) cells. Bioluminescence and fluorescence resonance energy transfer and the proximity ligation assay were exploited to demonstrate the formation of functional KOR and B2R heteromers in transfected cells. KOR/B2R heteromers triggered dynorphin A (1-13)-induced Gαs/protein kinase A signaling pathway activity, including upregulation of intracellular cAMP levels and cAMP-response element luciferase reporter activity, resulting in increased cAMP-response element-binding protein (CREB) phosphorylation, which could be dampened by the protein kinase A (PKA) inhibitor H89. This indicated that the co-existence of KOR and B2R is critical for CREB phosphorylation. In addition, dynorphin A (1-13) induced a significantly higher rate of proliferation in HEK293-KOR/B2R and human SH-SY5Y cells than in the control group. These results indicate that KOR can form a heterodimer with B2R and this leads to increased protein kinase A activity by the CREB signaling pathway, leading to a significant increase in cell proliferation. The nature of this signaling pathway has significant implications for the role of dynorphin in the regulation of neuroprotective effects.
authors.affiliation: School of Life Science, Shandong Agricultural University, Taian 271018, PR China; Neurobiology Institute, Jining Medical University, Jining 272067, PR China.
authors.forename: Bingyuan
authors.initials: B
authors.lastname: Ji
authors.affiliation: Department of Physiology, Taishan Medical College, Taian 271000, PR China.
authors.forename: Haiqing
authors.initials: H
authors.lastname: Liu
authors.affiliation: Neurobiology Institute, Jining Medical University, Jining 272067, PR China.
authors.forename: Rumin
authors.initials: R
authors.lastname: Zhang
authors.affiliation: Neurobiology Institute, Jining Medical University, Jining 272067, PR China.
authors.forename: Yunlu
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: Neurobiology Institute, Jining Medical University, Jining 272067, PR China.
authors.forename: Chunmei
authors.initials: C
authors.lastname: Wang
authors.affiliation: Neurobiology Institute, Jining Medical University, Jining 272067, PR China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Li
authors.affiliation: Neurobiology Institute, Jining Medical University, Jining 272067, PR China; Division of Translational and Systems Medicine, Warwick Medical School, University of Warwick, Coventry, UK. Electronic address: Jing.Chen@warwick.ac.uk.
authors.forename: Jing
authors.initials: J
authors.lastname: Chen
authors.affiliation: Neurobiology Institute, Jining Medical University, Jining 272067, PR China. Electronic address: bobai@mail.jnmc.edu.cn.
authors.forename: Bo
authors.initials: B
authors.lastname: Bai
mesh_terms: D000818:Animals; D049109:Cell Proliferation; D000242:Cyclic AMP / Q000378:metabolism; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D004399:Dynorphins / Q000378:metabolism*; D031541:Fluorescence Resonance Energy Transfer; D044385:GTP-Binding Protein alpha Subunits / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D008156:Luciferases / Q000378:metabolism; D051379:Mice; D010766:Phosphorylation; D055503:Protein Multimerization; D021381:Protein Transport; D043782:Receptor, Bradykinin B2 / Q000378:metabolism*; D017473:Receptors, Opioid, kappa / Q000378:metabolism*; D020218:Response Elements / Q000235:genetics; D015398:Signal Transduction; D010738:Type C Phospholipases / Q000378:metabolism
chemical_list: D017362:Cyclic AMP Response Element-Binding Protein; D044385:GTP-Binding Protein alpha Subunits; D043782:Receptor, Bradykinin B2; D017473:Receptors, Opioid, kappa; D004399:Dynorphins; D000242:Cyclic AMP; D008156:Luciferases; D017868:Cyclic AMP-Dependent Protein Kinases; D010738:Type C Phospholipases
keywords: Bradykinin B2 receptor (B2R); G-protein-coupled receptor (GPCR); Heterodimerization; Resonance energy transfer (RET); cAMP-response element-binding protein (CREB); κ-Opioid receptor (KOR)