title: N-terminal tetrapeptide T/SPLH motifs contribute to multimodal activation of human TRPA1 channel.
abstract: Human transient receptor potential ankyrin channel 1 (TRPA1) is a polymodal sensor implicated in pain, inflammation and itching. An important locus for TRPA1 regulation is the cytoplasmic N-terminal domain, through which various exogenous electrophilic compounds such as allyl-isothiocyanate from mustard oil or cinnamaldehyde from cinnamon activate primary afferent nociceptors. This major region is comprised of a tandem set of 17 ankyrin repeats (AR1-AR17), five of them contain a strictly conserved T/SPLH tetrapeptide motif, a hallmark of an important and evolutionarily conserved contribution to conformational stability. Here, we characterize the functional consequences of putatively stabilizing and destabilizing mutations in these important structural units and identify AR2, AR6, and AR11-13 to be distinctly involved in the allosteric activation of TRPA1 by chemical irritants, cytoplasmic calcium, and membrane voltage. Considering the potential involvement of the T/SP motifs as putative phosphorylation sites, we also show that proline-directed Ser/Thr kinase CDK5 modulates the activity of TRPA1, and that T673 outside the AR-domain is its only possible target. Our data suggest that the most strictly conserved N-terminal ARs define the energetics of the TRPA1 channel gate and contribute to chemical-, calcium- and voltage-dependence.
authors.affiliation: Department of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague 4, Czech Republic.
authors.forename: Anna
authors.initials: A
authors.lastname: Hynkova
authors.affiliation: Department of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague 4, Czech Republic.
authors.forename: Lenka
authors.initials: L
authors.lastname: Marsakova
authors.affiliation: Department of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague 4, Czech Republic.
authors.forename: Jana
authors.initials: J
authors.lastname: Vaskova
authors.affiliation: Department of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague 4, Czech Republic.
authors.forename: Viktorie
authors.initials: V
authors.lastname: Vlachova
mesh_terms: D000494:Allosteric Regulation; D017089:Ankyrin Repeat; D051360:Cyclin-Dependent Kinase 5 / Q000235:genetics / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D015640:Ion Channel Gating / Q000187:drug effects* / Q000235:genetics; D009154:Mutation; D009842:Oligopeptides / Q000737:chemistry / Q000494:pharmacology*; D000072417:Protein Domains; D000074025:TRPA1 Cation Channel / Q000235:genetics / Q000378:metabolism*
chemical_list: D009842:Oligopeptides; D000074025:TRPA1 Cation Channel; C473350:TRPA1 protein, human; D051360:Cyclin-Dependent Kinase 5; C495905:CDK5 protein, human