Homo-dimerization of RyR1 C-terminus via charged residues in random coils or in an alpha-helix.
- Author:
Eun Hui LEE
1
;
Paul D ALLEN
Author Information
1. Department of Physiology, College of Medicine, The Catholic University of Korea, Seoul 137-701, Korea. EHUI@catholic.ac.kr
- Publication Type:Original Article ; In Vitro ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
- Keywords:
mutagenesis, site-directed;
ryanodine receptor calcium release channel;
structure-activity relationship
- MeSH:
Amino Acid Sequence;
Animals;
Dimerization;
Models, Molecular;
Molecular Sequence Data;
Mutagenesis, Site-Directed;
Protein Structure, Quaternary;
Protein Structure, Secondary;
Rabbits;
Recombinant Fusion Proteins/chemistry/genetics;
Ryanodine Receptor Calcium Release Channel/*chemistry/genetics;
Sequence Homology, Amino Acid;
Static Electricity
- From:Experimental & Molecular Medicine
2007;39(5):594-602
- CountryRepublic of Korea
- Language:English
-
Abstract:
To investigate the mechanism by which the C-terminus (4,938-5,037) of the ryanodine receptor 1 (RyR1) homo-tetramerizes, forming a functional Ca2+ -release channel, the structural requirements for the tetramerization were studied using site-directed mutagenesis. Alanine-substitutions at five charged residues, E4976, H5003, D5026, E5033 and D5034, significantly decreased the formation of homo-dimers (reduced by > 50%). Interaction between the C-terminus and cytoplasmic loop I (4,821-4,835) required two positively charged residues, H4832 and K4835. Based on the predicted protein secondary structures, all seven charged residues are located in random coils. Paired alanine-substitutions at six negatively charged residues (E4942A/D4953A, D4945A/E4952A and E4948A/ E4955A) of the alpha-helix (4,940-4,956) in the C-terminus increased homo-dimerization. Therefore, the homo-tetramerization of RyR1 may be mediated by intra- and/or inter-monomer electrostatic interactions among the C-terminal charged residues in random coils or in an alpha-helix.
