The interactions of the C-terminal region of the TRPC6 channel with calmodulin.
The transient receptor potential channel TRPC6 is a non-selective cation channel which modulates the calcium level in eukaryotic cells (including sensory receptor cells) in response to external signals. Calmodulin (CaM) is a ubiquitously expressed Ca(2+) binding protein that is an important mediator of Ca(2+)-dependent regulation of the TRPC6 channel. One CaM binding site was identified within the C-tail of TRPC6. The aim of this study is to map in detail the CaM and inositol (1,4,5)-triphosphate receptor binding (CIRB) domain in the C-terminal region of mouse TRPC6 that is capable of interacting with CaM using in vitro binding assays. Besides the set of positively charged amino acid residues Arg852, Lys856, Arg864, Lys859/Arg860, a hydrophobic Ile857, at the position 1 in 1-5-10 motif, was located and the effect of replacing it with a neutral residue was tested using fluorescence anisotropy measurement. Participation of Ile857 could indicate a strong role of this conserved CaM binding motif.
Friedlova
Eliska
E
Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
Grycova
Lenka
L
Holakovska
Blanka
B
Silhan
Jan
J
Janouskova
Hana
H
Sulc
Miroslav
M
Obsilova
Veronika
V
Obsil
Tomas
T
Teisinger
Jan
J
D000818:Animals; D001665:Binding Sites; D002147:Calmodulin / Q000378:metabolism*; D003001:Cloning, Molecular; D024202:Electrophoretic Mobility Shift Assay; D005454:Fluorescence Polarization; D051379:Mice; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D011485:Protein Binding; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D050052:TRPC Cation Channels / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000074287:TRPC6 Cation Channel
D002147:Calmodulin; D050052:TRPC Cation Channels; D000074287:TRPC6 Cation Channel; C492146:Trpc6 protein, mouse