Identification and characterisation of novel tubulin-binding motifs located within the C-terminus of TRPV1.

Previously, we reported that TRPV1, the vanilloid receptor, interacts with soluble alphabeta-tubulin dimers as well as microtubules via its C-terminal cytoplasmic domain. The interacting region of TRPV1, however, has not been defined. We found that the TRPV1 C-terminus preferably interacts with beta-tubulin and less with alpha-tubulin. Using a systematic deletion approach and biotinylated-peptides we identified two tubulin-binding sites present in TRPV1. These two sequence stretches are highly conserved in all known mammalian TRPV1 orthologues and partially conserved in some of the TRPV1 homologues. As these sequence stretches are not similar to any known tubulin-binding sequences, we conclude that TRPV1 interacts with tubulin and microtubule through two novel tubulin-binding motifs.