Objective: The aim of the present study was to characterize 24 isolates of group C rotavirus (RV-C) by analysis of DNA sequences of the VP4, VP6, VP7 and NSP4 genes of several Brazilian states. Methods: All RV-C strains were confirmed by polyacrylamide gel electrophoresis and were characterized by sequence and phylogenetic analysis of the genes encoding NSP4, VP6, VP4, and VP7 proteins. Results...

Recent insights into the early events in Sindbis virus RNA replication suggest a requirement for either the P123 or P23 polyprotein, as well as mature nsP4, the RNA-dependent RNA polymerase, for initiation of minus-strand RNA synthesis. Based on this observation, we have succeeded in reconstituting an in vitro system for template-dependent initiation of SIN RNA replication. Extracts were isolat...

A partially conserved region spanning amino acids 142 to 191 of the Sindbis virus (SIN) nsP4 core polymerase is implicated in host restriction, elongation, and promoter recognition. We extended the analysis of this region by substituting Ser, Ala, or Lys for a highly conserved Arg183 residue immediately preceding its absolutely conserved Ser184-Ala-Val-Pro-Ser188 sequence. In chicken cells, the...

The mechanisms of diarrhea due to rotavirus infection in humans are not fully understood; no specific therapy is available, but orally administered human serum immunoglobulins are effective in blocking stool output. We aimed to investigate the effect of rotavirus on ion transport and the role of NSP4 in human-derived enterocytes, and to test the efficacy of human serum immunoglobulin in a model...

This investigation describes the molecular characterization of P[6]G2 rotavirus strains from hospitalized neonates with community-acquired diarrhea (CAD), nosocomial diarrhea (ND), and asymptomatic nosocomial infection (ANI) in Belém, Brazil. Twenty-six rotavirus strains with P[6]G2 genotype were sequenced to genes coding for VP4, VP7, and NSP4 proteins. Phylogenetic analysis of the VP4 gene, i...

Rotavirus (RV) is the major etiologic agent of severe infantile gastroenteritis; its genome has 11 segments of double stranded RNA, encoding 12 proteins. The non-structural protein 4 (NSP4) encoded by segment 10 is multifunctional. The aim of this study is to analyze the selective pressure driving the NSP4 of RV, through the ratio of non-synonymous substitutions per synonymous substitutions (dN...

Rotavirus nonstructural protein 4 (NSP4) induces dramatic changes in cellular calcium homeostasis. These include increased endoplasmic reticulum (ER) permeability, resulting in decreased ER calcium stores and activation of plasma membrane (PM) calcium influx channels, ultimately causing a 2- to 4-fold elevation in cytoplasmic calcium. Elevated cytoplasmic calcium is absolutely required for viru...

the rotavirus nonstructural protein 4 (nsp4), is a multi functional protein that play key role in both viral morphogenesis and cytopathic effect associated with cell death. however, the complete biological effect of nsp4 remains to be clarified. since to obtain further knowledge about this protein there is a need for recognizing antibody and there is no commercial antibody against this protein...