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Munc13 mediates klotho-inhibitable diacylglycerol-stimulated exocytotic insertion of pre-docked TRPC6 vesicles
Journal article   Open access   Peer reviewed

Munc13 mediates klotho-inhibitable diacylglycerol-stimulated exocytotic insertion of pre-docked TRPC6 vesicles

Jian Xie, Sung-Wan An, Xin Jin, Yuan Gui and Chou-Long Huang
PloS one, Vol.15(3), pp.e0229799-e0229799
03/05/2020
DOI: 10.1371/journal.pone.0229799
PMCID: PMC7058344
PMID: 32134975
url
https://doi.org/10.1371/journal.pone.0229799View
Published (Version of record) Open Access

Abstract

alpha-Klotho is a type 1 transmembrane protein that exhibits aging suppression function. The large amino-terminal extracellular domain of alpha -klotho is shed as soluble klotho (sKlotho) and functions as a circulating cardioprotective hormone. Diacylglycerol (DAG)-activated calcium-permeable TRPC6 channel plays a critical role in stress-induced cardiac remodeling. DAG activates TRPC6 by acting directly on the channel to increase its activity and by stimulation of channel exocytosis. sKlotho protects the heart by inhibiting DAG stimulation of TRPC6 exocytosis. How DAG stimulates TRPC6 exocytosis and thereby inhibition by sKlotho are unknown. Using a compound that directly activates TRPC6 without affecting channel exocytosis, we validate that sKlotho selectively blocks DAG stimulation of channel exocytosis. We further show that DAG stimulates exocytosis of TRPC6-containing vesicles pre-docked to the plasma membrane. Mnuc13 family proteins play important roles in the proper assembly of SNARE proteins and priming the vesicle competent for fusion. We show that DAG stimulates TRPC6 exocytosis by targeting to the C1 domain of Munc13-2. The results provide fresh insights into the molecular mechanism by which DAG regulates vesicle fusion and how sKlotho protects the heart against injury.
Multidisciplinary Sciences Science & Technology Science & Technology - Other Topics

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