Nikolaev YA, Cox CD, Ridone P, Rohde PR, Cordero-Morales JF, Vásquez V, Laver DR, Martinac B. Mammalian TRP ion channels are insensitive to membrane stretch.
J Cell Sci 2019;
132:jcs238360. [PMID:
31722978 PMCID:
PMC6918743 DOI:
10.1242/jcs.238360]
[Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 10/29/2019] [Indexed: 12/27/2022] Open
Abstract
TRP channels of the transient receptor potential ion channel superfamily are involved in a wide variety of mechanosensory processes, including touch sensation, pain, blood pressure regulation, bone loading and detection of cerebrospinal fluid flow. However, in many instances it is unclear whether TRP channels are the primary transducers of mechanical force in these processes. In this study, we tested stretch activation of eleven TRP channels from six mammalian subfamilies. We found that these TRP channels were insensitive to short membrane stretches in cellular systems. Furthermore, we purified TRPC6 and demonstrated its insensitivity to stretch in liposomes, an artificial bilayer system free from cellular components. Additionally, we demonstrated that, when expressed in C. elegans neurons, mouse TRPC6 restores the mechanoresponse of a touch insensitive mutant but requires diacylglycerol for activation. These results strongly suggest that the mammalian members of the TRP ion channel family are insensitive to tension induced by cell membrane stretching and, thus, are more likely to be activated by cytoplasmic tethers or downstream components and to act as amplifiers of cellular mechanosensory signaling cascades.
Collapse