Rabbit Anti-Human RYR1 (internal) Polyclonal antibody

Type 1 polysaccharide storage myopathy (PSSM1) and malignant hyperthermia (MH) are autosomal dominant genetic diseases caused by a point mutation in equine GYS1 and RYR1, respectively. Although the prevalence of PSSM1 and MH have been described in other countries as causes of myopathy in horses, there are no studies evaluating the allele frequency of those mutations in Brazil. The aim of the present study was to determine the allele frequency of the mutated alleles causing susceptibility for PSSM1 and MH mutations in Quarter Horses (QHs) in Brazil. Deoxyribonucleic acid was purified from blood samples of 741 QHs used in five competitive disciplines (i.e., barrel racing, cutting, halter, racing, and reining). The PCR was optimized to identify the mutations using primers designed from the sequence of equine GYS1 and RYR1. The allele frequencies and the prevalence of PSSM1 were 0.034 and 6.7%, respectively. The highest allele frequency for the GYS1 mutated gene was identified in halter horses (0.163), and the gene mutation was not observed in racing animals. The mutation in the RYR1 was not identified in any of the sampled horses. The PSSM1 allele frequency observed in the present study indicates the relevance of the disease in the differential diagnosis of myopathies in horses. In addition, the absence of the RYR1 causative mutation suggests little importance of MH as a genetic muscle disorder in the Brazilian QHs. (C) 2018 Elsevier Inc. All rights reserved.

The ryanodine receptors (RyR) are essential to calcium signaling in striated muscles, and numerous disease mutations have been identified in two RyR isoforms, RyRl in skeletal muscle and RyR2 in cardiac muscle. A deep understanding of the activation/ regulation mechanisms of RyRs has been hampered by the shortage of high-resolution structures and dynamic information for this giant tetrameric complex in different functional states. Toward elucidating the molecular mechanisms of disease mutations in RyRs, we performed molecular dynamics simulation of the N-terminal domain (NTD) which is not only the best-resolved structural component of RyRs, but also a hotspot of disease mutations. First, we simulated the tetrameric NTD of wild-type RyR1 and three disease mutants (K155E, R157Q, and R164Q) that perturb the inter-subunit interfaces. Our simulations identified a dynamic network of salt bridges involving charged residues at the inter-subunit/subdomain interfaces and disease-mutation sites. By perturbing this key network, the above three mutations result in greater flexibility with the highest inter-subunit opening probability for R157Q. Next, we simulated the monomeric NTD of RyR2 in the presence or absence of a central Cl- anion which is known to stabilize the interfaces between the three NTD subdomains (A, B, and C). We found that the loss of Cl- restructures the salt-bridge network near the Cl--binding site, leading to rotations of subdomain A/B relative to subdomain C and enhanced mobility between the subdomains. This finding supports a mechanism for disease mutations in the NTD of RyR2 via perturbation of the Cl- binding. The rich structural and dynamic information gained from this study will guide future mutational and functional studies of the NTD of RyRs. (C) 2017 Wiley Periodicals, Inc.