STRUCTURE AND FUNCTION OF ROTAVIRUS NSP1

Studies on the structure and function of the nonstructural proteins (N SP1-NSP5) of rotaviruses are important for dissection of the morphogen esis and replication processes of rotavirus. Above all, NSP1, the prod uct of gene 5, has several interesting features, such as extreme seque nce diversity, a highly conserved cysteine-rich region, RNA-binding ac tivity, accumulation on the cytoskeleton, and non-random segregation i n reassortment. Recently, comparable NSP1 sequence analysis has been p erformed on a number of rotavirus strains from various species. Furthe rmore, characterization of mutants with rearranged NSP1. genes has hel ped to elucidate the structure-function interaction of NSP1. We isolat ed and characterized two interesting mutants which have a large deleti on including the cysteine-rich region or a nonsense codon at the early portion in the open reading frame (ORF) of the NSP1 gene. In this rep ort, we summarize the structure and function of NSP1.