Laboratory of Ion Channel Research

The mammalian TRPV subfamily, named after the vanilloid receptor 1 (VR1, now TRPV1), contains six members, TRPV1-TRPV6. The N-terminus of each TRPV channel includes three to four ankyrin repeats, the C-terminus contains a TRP domain.

• TRPV1-TRPV4, which share 40 to 50% amino acid homology, are temperature sensitive Ca²⁺-permeable, non selective cation channels.
  • TRPV1, first identified as a receptor that binds capsaicin, is a relatively Ca²⁺-selective ion channel with an outwardly rectifying current-voltage relation and Ca²⁺-dependent desensitisation. 
  • TRPV2 is ~50% identical to TRPV1 but is insensitive to capsaicin and low pH. It is activated by heat at a higher temperature threshold than TRPV1 (>52°C).
  • TRPV3 is temperature sensitive in the physiologic temperature range (31 to 39°C).
  • TRPV4, first described as a channel activated by hypotonicity-induced cell swelling, is also temperature sensitive, and activated by acid pH, mechanical stimuli and chemical compounds (4α-phorbol didecanoate, arachidonic acid [AA], and 5,6-epoxyeicosatrienoic acid [5,6-EET]).
• TRPV5 and TRPV6 are Ca²⁺-permeable TRP channels with a very high selectivity for Ca²⁺ (P_Ca/P_Na > 100:1).