title: Directionality of temperature activation in mouse TRPA1 ion channel can be inverted by single-point mutations in ankyrin repeat six.
abstract: Several transient receptor potential (TRP) ion channels are activated with high sensitivity by either cold or hot temperatures. However, structures and mechanism that determine temperature directionality (cold versus heat) are not established. Here we screened 12,000 random mutant clones of the cold-activated mouse TRPA1 ion channel with a heat stimulus. We identified three single-point mutations that are individually sufficient to make mouse TRPA1 warm activated, while leaving sensitivity to chemicals unaffected. Mutant channels have high temperature sensitivity of voltage activation, specifically of channel opening, but not channel closing, which is reminiscent of other heat-activated TRP channels. All mutations are located in ankyrin repeat six, which identifies this domain as a sensitive modulator of thermal activation. We propose that a change in the coupling of temperature sensing to channel gating generates this sensitivity to warm temperatures. Our results demonstrate that minimal changes in protein sequence are sufficient to generate a wide diversity of thermal sensitivities in TRPA1.
authors.affiliation: Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: Sairam
authors.initials: S
authors.lastname: Jabba
authors.affiliation: Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: Raman
authors.initials: R
authors.lastname: Goyal
authors.affiliation: Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: Jason O
authors.initials: JO
authors.lastname: Sosa-Pagán
authors.affiliation: Centro Interdisciplinario de Neurociencias de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2349400, Chile.
authors.forename: Hans
authors.initials: H
authors.lastname: Moldenhauer
authors.affiliation: Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: Jason
authors.initials: J
authors.lastname: Wu
authors.affiliation: Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: Breanna
authors.initials: B
authors.lastname: Kalmeta
authors.affiliation: Department of Cell Biology, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA; Genomics Institute of the Novartis Research Foundation, La Jolla, CA 92037, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Bandell
authors.affiliation: Centro Interdisciplinario de Neurociencias de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2349400, Chile.
authors.forename: Ramon
authors.initials: R
authors.lastname: Latorre
authors.affiliation: Department of Cell Biology, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA; Genomics Institute of the Novartis Research Foundation, La Jolla, CA 92037, USA.
authors.forename: Ardem
authors.initials: A
authors.lastname: Patapoutian
authors.affiliation: Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA. Electronic address: grandl@neuro.duke.edu.
authors.forename: Jörg
authors.initials: J
authors.lastname: Grandl
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017089:Ankyrin Repeat / Q000235:genetics*; D016466:CHO Cells; D003412:Cricetulus; D004330:Drosophila; D051379:Mice; D008969:Molecular Sequence Data; D017354:Point Mutation; D000074025:TRPA1 Cation Channel; D013696:Temperature; D050051:Transient Receptor Potential Channels / Q000235:genetics / Q000378:metabolism*
chemical_list: D000074025:TRPA1 Cation Channel; D050051:Transient Receptor Potential Channels; C475685:Trpa1 protein, mouse