The binding of the RyR2 calcium channel to its gating protein FKBP12.6 is oppositely affected by ARVD2 and VTSIP mutations.
Arrhythmogenic right ventricular dysplasia/cardiomyopathy type 2 (ARVD2, OMIM 600996) and stress-induced polymorphic ventricular tachycardia (VTSIP, OMIM 604772) are two cardiac diseases causing juvenile sudden death, both associated with mutations in the RyR2 calcium channel. By using a quantitative yeast two-hybrid system, we show that VTSIP- and ARVD2-associated point mutations influence positively and negatively, respectively, the binding of RyR2 to its gating protein FKBP12.6. These findings suggest that ARVD2 mutations increase RyR2-mediated calcium release to cytoplasm, while VTSIP mutations do not affect significantly cytosolic calcium levels, thereby explaining the clinical differences between the two diseases. The present two-hybrid system appears to be an efficient molecular tool to assay the binding of FKBP12s proteins to both cardiac RyR2 and skeletal muscle RyR1 isoforms, circumventing the full-length expression of this class of giant channels. We also provide evidence of the suitability of this system to test new drugs that target RyRs-FKBP12s interactions and do not affect yeast growth.
Tiso
Natascia
N
Department of Biology, University of Padova, via U. Bassi 58/B, I-35131 Padua, Italy. natascia@telethon.bio.unipd.it
Salamon
Michela
M
Bagattin
Alessia
A
Danieli
Gian Antonio
GA
Argenton
Francesco
F
Bortolussi
Marino
M
D019571:Arrhythmogenic Right Ventricular Dysplasia / Q000235:genetics*; D002118:Calcium / Q000378:metabolism; D006801:Humans; D016297:Mutagenesis, Site-Directed; D017354:Point Mutation; D011485:Protein Binding; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D019837:Ryanodine Receptor Calcium Release Channel / Q000235:genetics / Q000378:metabolism*; D017180:Tachycardia, Ventricular / Q000235:genetics*; D022021:Tacrolimus Binding Proteins / Q000235:genetics / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
D020033:Protein Isoforms; D019837:Ryanodine Receptor Calcium Release Channel; D022021:Tacrolimus Binding Proteins; C403484:tacrolimus binding protein 1B; D002118:Calcium