机构：[a]Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Canada[b]Bone and Joint Institute, The University of Western Ontario, London, Canada[c]Dentistry, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Canada[d]Department of Biology, Faculty of Science, The University of Western Ontario, London, Canada[e]Department of Anesthesiology, Sichuan Cancer Hospital & Institute, Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China.四川省人民医院四川省肿瘤医院
Parathyroid hormone (PTH) activates the PTH/PTH-related peptide receptor (PTH1R) on osteoblasts and other target cells. Mechanical stimulation of cells, including osteoblasts, causes release of nucleotides such as ATP into the extracellular fluid. In addition to its role as an energy source, ATP serves as an agonist at P2 receptors and an allosteric regulator of many proteins. We investigated the effects of concentrations of extracellular ATP, comparable to those that activate low affinity P2X7 receptors, on PTH1R signaling. Cyclic AMP levels were monitored in real-time using a bioluminescence reporter and beta-arrestin recruitment to PTH1R was followed using a complementation-based luminescence assay. ATP markedly enhanced cyclic AMP and beta-arrestin signaling as well as downstream activation of CREB. CMP - a nucleotide that lacks a high energy bond and does not activate P2 receptors - mimicked this effect of ATP. Moreover, potentiation was not inhibited by P2 receptor antagonists, including a specific blocker of P2X7. Thus, nucleotide-induced potentiation of signaling pathways was independent of P2 receptor signaling. ATP and CMP reduced the concentration of PTH (1-34) required to produce a half-maximal cyclic AMP or beta-arrestin response, with no evident change in maximal receptor activity. Increased potency was similarly apparent with PTH1R agonists PTH (1-14) and PTH-related peptide (1-34). These observations suggest that extracellular nucleotides increase agonist affinity, efficacy or both, and are consistent with modulation of signaling at the level of the receptor or a closely associated protein. Taken together, our findings establish that ATP enhances P TH1R signaling through a heretofore unrecognized allosteric mechanism.
基金：
This work was funded by the Canadian Institutes of Health Research
[grant number 142201]. B. Kim was supported in part by a
Transdisciplinary Bone & Joint Training Award from the Collaborative
Training Program in Musculoskeletal Health Research at The University
of Western Ontario.
第一作者机构：[a]Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Canada[b]Bone and Joint Institute, The University of Western Ontario, London, Canada
共同第一作者：
通讯作者：
通讯机构：[a]Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Canada[b]Bone and Joint Institute, The University of Western Ontario, London, Canada[d]Department of Biology, Faculty of Science, The University of Western Ontario, London, Canada[*1]Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario N6A 5C1, Canada.
推荐引用方式(GB/T 7714)：
Brandon H. Kim,Alexey Pereverzev,Shuying Zhu,et al.Extracellular nucleotides enhance agonist potency at the parathyroid hormone 1 receptor[J].CELLULAR SIGNALLING.2018,46:103-112.doi:10.1016/j.cellsig.2018.02.015.
APA：
Brandon H. Kim,Alexey Pereverzev,Shuying Zhu,Abby Oi Man Tong,S. Jeffrey Dixon&Peter Chidiac.(2018).Extracellular nucleotides enhance agonist potency at the parathyroid hormone 1 receptor.CELLULAR SIGNALLING,46,
MLA：
Brandon H. Kim,et al."Extracellular nucleotides enhance agonist potency at the parathyroid hormone 1 receptor".CELLULAR SIGNALLING 46.(2018):103-112
