Format

Send to

Choose Destination
Int J Mol Sci. 2019 Sep 9;20(18). pii: E4430. doi: 10.3390/ijms20184430.

TRPM6 N-Terminal CaM- and S100A1-Binding Domains.

Author information

1
Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo namesti 2, 160 00 Prague 6, Czech Republic. monika.vargova@uochb.cas.cz.
2
Second Faculty of Medicine, Charles University, V Uvalu 84, 150 06 Prague 5, Czech Republic. monika.vargova@uochb.cas.cz.
3
Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, 121 16 Prague 2, Czech Republic. herman@karlov.mff.cuni.cz.
4
Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, 121 16 Prague 2, Czech Republic. hofbauer@karlov.mff.cuni.cz.
5
Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague 4, Czech Republic. hofbauer@karlov.mff.cuni.cz.
6
Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo namesti 2, 160 00 Prague 6, Czech Republic. jiri.vondrasek@uochb.cas.cz.
7
Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo namesti 2, 160 00 Prague 6, Czech Republic. kristyna.bousova@uochb.cas.cz.

Abstract

Transient receptor potential (TRPs) channels are crucial downstream targets of calcium signalling cascades. They can be modulated either by calcium itself and/or by calcium-binding proteins (CBPs). Intracellular messengers usually interact with binding domains present at the most variable TRP regions-N- and C-cytoplasmic termini. Calmodulin (CaM) is a calcium-dependent cytosolic protein serving as a modulator of most transmembrane receptors. Although CaM-binding domains are widespread within intracellular parts of TRPs, no such binding domain has been characterised at the TRP melastatin member-the transient receptor potential melastatin 6 (TRPM6) channel. Another CBP, the S100 calcium-binding protein A1 (S100A1), is also known for its modulatory activities towards receptors. S100A1 commonly shares a CaM-binding domain. Here, we present the first identified CaM and S100A1 binding sites at the N-terminal of TRPM6. We have confirmed the L520-R535 N-terminal TRPM6 domain as a shared binding site for CaM and S100A1 using biophysical and molecular modelling methods. A specific domain of basic amino acid residues (R526/R531/K532/R535) present at this TRPM6 domain has been identified as crucial to maintain non-covalent interactions with the ligands. Our data unambiguously confirm that CaM and S100A1 share the same binding domain at the TRPM6 N-terminus although the ligand-binding mechanism is different.

KEYWORDS:

CaM and S100A1; TRPM6; binding domain; calmodulin binding motif; fluorescence anisotropy; molecular modelling

PMID:
31505788
DOI:
10.3390/ijms20184430
Free full text

Supplemental Content

Full text links

Icon for Multidisciplinary Digital Publishing Institute (MDPI)
Loading ...
Support Center