title: Identification of a tetramerization domain in the C terminus of the vanilloid receptor.
abstract: TRPV1 (transient receptor potential vanilloid receptor subtype 1) is a member of the TRP channel family gated by vanilloids, protons, and heat. Structurally, TRPV1 appears to be a tetramer formed by the assembly of four identical subunits around a central aqueous pore. The molecular determinants that govern its subunit oligomerization remain elusive. Here, we report the identification of a segment comprising 684Glu-721Arg (referred to as the TRP-like domain) in the C terminus of TRPV1 as an association domain (AD) of the protein. Purified recombinant C terminus of TRPV1 (TRPV1-C) formed discrete and stable multimers in vitro. Yeast two-hybrid and pull-down assays showed that self-association of the TRPV1-C is blocked when segment 684Glu-721Arg is deleted. Biochemical and immunological analysis indicate that removal of the AD from full-length TRPV1 monomers blocks the formation of stable heteromeric assemblies with wild-type TRPV1 subunits. Deletion of the AD in a poreless TRPV1 subunit suppressed its robust dominant-negative phenotype. Together, these findings are consistent with the tenet that the TRP-like domain in TRPV1 is a molecular determinant of the tetramerization of receptor subunits into functional channels. Our observations suggest that the homologous TRP domain in the TRP protein family may function as a general, evolutionary conserved AD involved in subunit multimerization.
authors.affiliation: Instituto de Biologia Molecular y Celular, Universidad Miguel Hernandez, 03202 Alicante, Spain.
authors.forename: Nuria
authors.initials: N
authors.lastname: García-Sanz
authors.forename: Asia
authors.initials: A
authors.lastname: Fernández-Carvajal
authors.forename: Cruz
authors.initials: C
authors.lastname: Morenilla-Palao
authors.forename: Rosa
authors.initials: R
authors.lastname: Planells-Cases
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Fajardo-Sánchez
authors.forename: Gregorio
authors.initials: G
authors.lastname: Fernández-Ballester
authors.forename: Antonio
authors.initials: A
authors.lastname: Ferrer-Montiel
mesh_terms: D001120:Arginine; D015870:Gene Expression; D005973:Glutamine; D006801:Humans; D016133:Polymerase Chain Reaction; D021122:Protein Subunits / Q000737:chemistry; D011955:Receptors, Drug / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism; D017422:Sequence Analysis, DNA; D009435:Synaptic Transmission
chemical_list: D021122:Protein Subunits; D011955:Receptors, Drug; D005973:Glutamine; D001120:Arginine