APVV-0139-06

Principal Investigator: Jozef Sevcik

Duration: February 2007 – December 2009
Coordinating Organization: Institute of Molecular Biology SAS, Bratislava

Annotation:

Proper regulation of ryanodine receptors (RyRs) is central to maintaining Ca2+ homeostasis in the periodically contracting myocytes. This regulation is impaired in genetic diseases CPVT-1 and ARVD-2, in which RyRs have mutations. We will determine the structure of two specific RyR domains from regions with frequent occurrence of CPVT/ARVD mutations (“domain switch”), important from the viewpoint of allosteric regulation of channel opening, and study their role in modulating resting RyR activity. The structure of the domains as well as of their complex will be determined. The effect of peptide fragments derived from the domains on resting RyR activity will by studied electrophysiologically and by confocal microscopy. The mechanism of interaction between individual functional modules of the RyR will be dissected using allosteric models of RyR activity. Successful completion of the project , i.e., determination of the structure and the principle of function of the domains will enable deeper understanding of “domain switch” function and of molecular mechanisms leading to CPVT arrhythmias.

Keywords:

Excitation-contraction coupling, CPVT arrhythmias, ryanodine receptor, protein structure, calcium signaling

Objectives:

• To verify the hypothesis that interaction between the N-terminal and the central domain of the “domain switch” is mediated via amino acids, whose mutations cause CPVT-1 and/or ARVD-2.
• To verify the hypothesis that defect in the interaction between the N-terminal and the central domain result in increased resting activity of the RyR.

Publications: