PKC-dependent Phosphorylation of the H1 Histamine Receptor Modulates TRPC6 Activity

Cells

Xingjuan Chen¹  Christian Egly¹  Ashley M. Riley¹  Wennan Li¹  Paul Tewson²  Thomas E. Hughes²  Anne Marie Quinn² 

[1] Indiana University School of Medicine, 635 Barnhill Dr., MS360A, Indianapolis, IN 46202, USA;Montana Molecular, Bozeman, MT 59715, USA

关键词: TRPC6;    desensitization;    DAG;    PKC;    H1 receptor;   

DOI  :  10.3390/cells3020247

来源: mdpi

【 摘 要 】

Transient receptor potential canonical 6 (TRPC6) is a cation selective, DAG-regulated, Ca²⁺-permeable channel activated by the agonists of G_q-protein-coupled heptahelical receptors. Dysfunctions of TRPC6 are implicated in the pathogenesis of various cardiovascular and kidney conditions such as vasospasm and glomerulosclerosis. When stimulated by agonists of the histamine H1 receptor (H1R), TRPC6 activity decays to the baseline despite the continuous presence of the agonist. In this study, we examined whether H1R desensitization contributes to regulating the decay rate of TRPC6 activity upon receptor stimulation. We employed the HEK expression system and a biosensor allowing us to simultaneously detect the changes in intracellular diacylglycerol (DAG) and Ca²⁺ concentrations. We found that the histamine-induced DAG response was biphasic, in which a transient peak was followed by maintained elevated plateau, suggesting that desensitization of H1R takes place in the presence of histamine. The application of PKC inhibitor Gö6983 slowed the decay rate of intracellular DAG concentration. Activation of the mouse H1R mutant lacking a putative PKC phosphorylation site, Ser399, responsible for the receptor desensitization, resulted in a prolonged intracellular DAG increase and greater Mn²⁺ influx through the TRPC6 channel. Thus, our data support the hypothesis that PKC-dependent H1R phosphorylation leads to a reduced production of intracellular DAG that contributes to TRPC6 activity regulation.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.