L. Grycova, B. Holakovska, J. Teisinger


Department of Protein Structures, Institute of Physiology, Academy of Sciences of the Czech Republic, Videnska 1083, Praha 4, 142 20



The transient receptor potential channel TRPC6 is a non-selective cation channel involved in regulation of calcium levels in eukaryotic cells (including sensory receptor cells) in response to external signals. Calmodulin (CaM) is a ubiquitously expressed Ca2+-binding protein that serves as an important mediator of Ca2+-dependent regulation of the TRPC6 channel. One CaM binding site has been identified within the C-tail of TRPC6.

In this project we mapped in detail the CaM and inositol (1,4,5)-triphosphate receptor binding (CIRB) domain in the C-terminal region of mouse TRPC6 (801-878) capable of interacting with CaM using in vitro binding assays. Besides we used a set of positively charged amino acid residues Arg852, Lys856, Arg864 and Lys859/Arg860, and a hydrophobic residue Ile857 placed in position 1 in consensus CaM binding motif 1-5-10. We replaced these amino acids with neutral alanine and investigated role of the residues in CaM binding to TRPC6 C-terminus using fluorescence anisotropy measurement. Participation of Ile857 could indicate a strong role of this conserved CaM binding motif.


This project was supported by Grant GAAV IAA600110701, GACR 301/10/1159, GACR P205/10/P308, project (No. H148), Centre of Neurosciences No. LC554 MSMT CR, Research project No. AV0Z.