title: Inhibition of CaV2.3 channels by NK1 receptors is sensitive to membrane cholesterol but insensitive to caveolin-1.
abstract: Voltage-gated, CaV2.3 calcium channels and neurokinin-1 (NK1) receptors are both present in nuclei of the central nervous system. When transiently coexpressed in human embryonic kidney (HEK) 293 cells, CaV2.3 is primarily inhibited during strong, agonist-dependent activation of NK1 receptors. NK1 receptors localize to plasma membrane rafts, and their modulation by Gq/11 protein-coupled signaling is sensitive to plasma membrane cholesterol. Here, we show that inhibition of CaV2.3 by NK1 receptors is attenuated following methyl-β-cyclodextrin (MBCD)-mediated depletion of membrane cholesterol. By contrast, inhibition of CaV2.3 was unaffected by intracellular diffusion of caveolin-1 scaffolding peptide or by overexpression of caveolin-1. Interestingly, MΒCD treatment had no effect on the macroscopic biophysical properties of CaV2.3, though it significantly decreased whole-cell membrane capacitance. Our data indicate that (1) cholesterol supports at least one component of the NK1 receptor-linked signaling pathway that inhibits CaV2.3 and (2) caveolin-1 is dispensable within this pathway. Our findings suggest that NK1 receptors reside within non-caveolar membrane rafts and that CaV2.3 resides nearby but outside the rafts. Raft-dependent modulation of CaV2.3 could be important in the physiological and pathophysiological processes in which these channels participate, including neuronal excitability, synaptic plasticity, epilepsy, and chronic pain.
authors.affiliation: Department of Physiology and Biophysics, College of Medicine, Universidad Autónoma de San Luis Potosí, Carranza #2405, San Luis Potosí, SLP, 78210, México.
authors.forename: Yamhilette
authors.initials: Y
authors.lastname: Licon
authors.forename: Deniss
authors.initials: D
authors.lastname: Leandro
authors.forename: Catalina
authors.initials: C
authors.lastname: Romero-Mendez
authors.forename: Aldo A
authors.initials: AA
authors.lastname: Rodriguez-Menchaca
authors.forename: Sergio
authors.initials: S
authors.lastname: Sanchez-Armass
authors.forename: Ulises
authors.initials: U
authors.lastname: Meza
mesh_terms: D000818:Animals; D020908:Calcium Channels, R-Type / Q000235:genetics / Q000378:metabolism*; D051242:Caveolin 1 / Q000235:genetics / Q000378:metabolism*; D002784:Cholesterol / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D021962:Membrane Microdomains / Q000187:drug effects / Q000378:metabolism*; D008564:Membrane Potentials; D011817:Rabbits; D051381:Rats; D020239:Receptor Cross-Talk; D018040:Receptors, Neurokinin-1 / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D047392:beta-Cyclodextrins / Q000494:pharmacology
chemical_list: D020908:Calcium Channels, R-Type; C495537:Cav1 protein, rat; D051242:Caveolin 1; D018040:Receptors, Neurokinin-1; D047392:beta-Cyclodextrins; C108732:methyl-beta-cyclodextrin; D002784:Cholesterol