Referenced in: none

Automatically associated channels: TRP , TRPM , TRPM3

Title: PtdIns(4,5)P 2 interacts with CaM binding domains on TRPM3 N-terminus.

Authors: Blanka Holendova, Lenka Grycova, Michaela Jirku, Jan Teisinger

Journal, date & volume: Channels (Austin), 2012 Nov 1 , 6, 479-82

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/22989896

Abstract
TRPM3 has been reported to play an important role in Ca(2+) homeostasis, but its gating mechanisms and regulation via Ca(2+) are unknown. Ca(2+) binding proteins such as calmodulin (CaM) could be probable modulators of this ion channel. We have shown that this protein binds to two independent domains, A35-K124 and H291-G382 on the TRPM3 N-terminus, which contain conserved hydrophobic as well as positively charged residues in specific positions, and that these residues have a crucial impact on its binding. We also showed that the other Ca(2+) binding protein, S100A1, is able to bind to these regions and that CaM and S100A1 compete for these binding sites on the TRPM3 N-terminus. Moreover, our results suggest that another very important TRP channel activity modulator, PtdIns(4,5)P(2), interacts with the CaM/S100A1 binding sites on the TRPM3 N-terminus with high affinity.