The transient receptor potential vanilloid receptor-1 (TRPV1) is a sensory neuron-specific nonselective cation channel that is gated in response to various noxious stimuli: pungent vanilloids, low pH, noxious heat, and depolarizing voltages. By its analogy to K+ channels, the S6 inner helix domain of TRPV1 (Y666-G683) is a prime candidate to form the most constricted region of the permeation pathway and might therefore encompass an as-yet-unmapped gate of the channel. Using alanine-scanning mutagenesis, we identified 16 of 17 residues, that when mutated affected the functionality of the TRPV1 channel with respect to at least one stimulus modality. T670A was the only substitution producing the wild-type channel phenotype, whereas Y666A and N676A were nonfunctional but present at the plasma membrane. The periodicity of the functional effects of mutations within the TRPV1 inner pore region is consistent with an alpha-helical structure in which T670 and A680 might play the roles of two bending "hinges."

• MeSH
• alanin MeSH
• buněčné linie MeSH
• elektrofyziologie MeSH
• gating iontového kanálu fyziologie   MeSH
• kapsaicin farmakologie   MeSH
• kationtové kanály TRPV chemie   účinky léků   genetika   fyziologie   MeSH
• krysa rodu Rattus MeSH
• lidé MeSH
• membránové potenciály MeSH
• mutace MeSH
• mutageneze cílená MeSH
• vysoká teplota MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• alanin MeSH
• kapsaicin MeSH
• kationtové kanály TRPV MeSH
• Trpv1 protein, rat MeSH Prohlížeč

The vanilloid receptor [transient receptor potential (TRP)V1, also known as VR1] is a member of the TRP channel family. These receptors share a significant sequence homology, a similar predicted structure with six transmembrane-spanning domains (S1-S6), a pore-forming region between S5 and S6, and the cytoplasmically oriented C- and N-terminal regions. Although structural/functional studies have identified some of the key amino acids influencing the gating of the TRPV1 ion channel, the possible contributions of terminal regions to vanilloid receptor function remain elusive. In the present study, C-terminal truncations of rat TRPV1 have been constructed to characterize the contribution of the cytoplasmic C-terminal region to TRPV1 function and to delineate the minimum amount of C tail necessary to form a functional channel. The truncation of 31 residues was sufficient to induce changes in functional properties of TRPV1 channel. More pronounced effects of C-terminal truncation were seen in mutants lacking the final 72 aa. These changes were characterized by a decline of capsaicin-, pH-, and heat-sensitivity; progressive reduction of the activation thermal threshold (from 41.5 to 28.6 degrees C); and slowing of the activation rate of heat-evoked membrane currents (Q10 from 25.6 to 4.7). The voltage-induced currents of the truncated mutants exhibited a slower onset, markedly reduced outward rectification, and significantly smaller peak tail current amplitudes. Truncation of the entire TRPV1 C-terminal domain (155 residues) resulted in a nonfunctional channel. These results indicate that the cytoplasmic COOH-terminal domain strongly influences the TRPV1 channel activity, and that the distal half of this structural domain confers specific thermal sensitivity.

• MeSH
• buněčné linie MeSH
• elektrická vodivost MeSH
• imunohistochemie MeSH
• kapsaicin farmakologie   MeSH
• koncentrace vodíkových iontů MeSH
• krysa rodu Rattus MeSH
• lidé MeSH
• metoda terčíkového zámku MeSH
• molekulární modely MeSH
• molekulární sekvence - údaje MeSH
• mutace MeSH
• proteinkinasa C metabolismus   MeSH
• protony MeSH
• receptory léků chemie   genetika   fyziologie   MeSH
• sekvence aminokyselin MeSH
• sekvenční delece MeSH
• sekvenční seřazení MeSH
• serin genetika   MeSH
• terciární struktura proteinů MeSH
• vysoká teplota MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• kapsaicin MeSH
• proteinkinasa C MeSH
• protony MeSH
• receptory léků MeSH
• serin MeSH