Identification of a tetramerization domain in the C terminus of the vanilloid receptor.
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.
García-Sanz
Nuria
N
Instituto de Biologia Molecular y Celular, Universidad Miguel Hernandez, 03202 Alicante, Spain.
Fernández-Carvajal
Asia
A
Morenilla-Palao
Cruz
C
Planells-Cases
Rosa
R
Fajardo-Sánchez
Emmanuel
E
Fernández-Ballester
Gregorio
G
Ferrer-Montiel
Antonio
A
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
D021122:Protein Subunits; D011955:Receptors, Drug; D005973:Glutamine; D001120:Arginine