Faculty Collaboration Database

Phosphorylation of distal C-terminal residues promotes TRPV4 channel activation in response to arachidonic acid. J Biol Chem 2025 Mar;301(3):108260

Date

02/06/2025

Pubmed ID

39909371

Pubmed Central ID

PMC11903807

DOI

10.1016/j.jbc.2025.108260

Scopus ID

2-s2.0-85218338007 (requires institutional sign-in at Scopus site)   5 Citations

Abstract

Transient receptor potential vanilloid 4 (TRPV4) is a Ca²⁺-permeable channel activated by diverse physical and chemical stimuli, including mechanical stress and endogenous lipid arachidonic acid (AA) and its metabolites. Phosphorylation of TRPV4 by protein kinase A (PKA) and protein kinase C (PKC) is a predominant mechanism for channel regulation, especially in the cytoplasmic domains due to their importance in protein assembly, and channelopathies. However, studies corresponding to phosphorylation sites for these kinases remain incomplete. We investigated the role of Ser-823 residue as a potential phosphorylation site in regulating TRPV4 activity and chemical agonist-induced channel activation. Using mass spectrometry, we identified a new phosphorylation site Ser-823 residue and confirmed the previously known phosphorylation site Ser-824 in the C-terminal tail. The low level of phosphorylation at Ser-823 was stimulated by PKC and to a lesser extent by PKA in human coronary artery endothelial cells (HCAECs) and human embryonic kidney 293 (HEK 293) cells. AA-induced TRPV4 activation was enhanced in the phosphomimetic S823E but was blunted in the S823A/S824A mutants, whereas the channel activation by the synthetic agonist GSK1016790A was unaffected. Further, TRPV4 activation by AA but not GSK1016790A was blunted or abolished by PKA inhibitor alone or in combination with PKC inhibitor, respectively. Using computational modeling, we refined a previously proposed structural model for TRPV4 regulation by Ser-823 and Ser-824 phosphorylation. Together, these results provide insight into how stimuli-specific TRPV4 activation is regulated by the phosphorylation of discrete residues (e.g., Ser-823 and Ser-824) in the C-terminal domains of the TRPV4 channel.

Author List

Parthasarathy A, Anishkin A, Xie Y, Drachuk K, Nishijma Y, Fang J, Koukouritaki SB, Wilcox DA, Zhang DX

Authors

Kostiantyn Drachuk Postdoctoral Researcher 3 in the Medicine department at Medical College of Wisconsin
Sevasti Koukouritaki Research Scientist II in the Pediatrics department at Medical College of Wisconsin
Aravind Parthasarathy PhD, MS Postdoctoral Researcher 4 in the Medicine department at Medical College of Wisconsin
David A. Wilcox PhD Professor in the Pediatrics department at Medical College of Wisconsin
David X. Zhang PhD Associate Professor in the Medicine department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals
Arachidonic Acid
Cyclic AMP-Dependent Protein Kinases
Endothelial Cells
HEK293 Cells
Humans
Phosphorylation
Protein Kinase C
TRPV Cation Channels