Publication Date:
2010-11-05
Description:
Many physiological events require transient increases in cytosolic Ca(2+) concentrations. Ryanodine receptors (RyRs) are ion channels that govern the release of Ca(2+) from the endoplasmic and sarcoplasmic reticulum. Mutations in RyRs can lead to severe genetic conditions that affect both cardiac and skeletal muscle, but locating the mutated residues in the full-length channel structure has been difficult. Here we show the 2.5 A resolution crystal structure of a region spanning three domains of RyR type 1 (RyR1), encompassing amino acid residues 1-559. The domains interact with each other through a predominantly hydrophilic interface. Docking in RyR1 electron microscopy maps unambiguously places the domains in the cytoplasmic portion of the channel, forming a 240-kDa cytoplasmic vestibule around the four-fold symmetry axis. We pinpoint the exact locations of more than 50 disease-associated mutations in full-length RyR1 and RyR2. The mutations can be classified into three groups: those that destabilize the interfaces between the three amino-terminal domains, disturb the folding of individual domains or affect one of six interfaces with other parts of the receptor. We propose a model whereby the opening of a RyR coincides with allosterically coupled motions within the N-terminal domains. This process can be affected by mutations that target various interfaces within and across subunits. The crystal structure provides a framework to understand the many disease-associated mutations in RyRs that have been studied using functional methods, and will be useful for developing new strategies to modulate RyR function in disease states.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Tung, Ching-Chieh -- Lobo, Paolo A -- Kimlicka, Lynn -- Van Petegem, Filip -- Canadian Institutes of Health Research/Canada -- England -- Nature. 2010 Nov 25;468(7323):585-8. doi: 10.1038/nature09471. Epub 2010 Nov 3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21048710" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
*Models, Molecular
;
Mutation/genetics
;
Protein Structure, Tertiary
;
Rabbits
;
Ryanodine Receptor Calcium Release Channel/*chemistry/*genetics/metabolism
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
