NSP1

About: NSP1 is a research topic. Over the lifetime, 248 publications have been published within this topic receiving 12044 citations.

Structure and function of rotavirus NSP1.

Abstract: Studies on the structure and function of the nonstructural proteins (NSP1-NSP5) of rotaviruses are important for dissection of the morphogenesis and replication processes of rotavirus. Above all, NSP1, the product of gene 5, has several interesting features, such as extreme sequence diversity, a highly conserved cysteine-rich region, RNA-binding activity, accumulation on the cytoskeleton, and non-random segregation in reassortment. Recently, comparable NSP1 sequence analysis has been performed on a number of rotavirus strains from various species. Furthermore, characterization of mutants with rearranged NSP1 genes has helped to elucidate the structure-function interaction of NSP1. We isolated and characterized two interesting mutants which have a large deletion 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 report, we summarize the structure and function of NSP1.

Analysis on reassortment of rotavirus NSP1 genes lacking coding region for cysteine-rich zinc finger motif.

Abstract: Rotavirus clones Aff5–10 and Aff5–16 isolated from a bovine rotavirus strain Aff5 possess NSP1 gene which has a point mutation generating a nonsense codon and a 500 base-deletion, respectively. As a result, the two Aff5 clones encode truncated NSP1 product which lacks cysteine-rich region forming zinc finger motif. In order to analyze reassortment of these mutated NSP1 gene with RNA segments from heterologous strains, we investigated a number of reassortant clones derived from coinfection with either Aff5–10, Aff5–16 or a reference strain Aff5–13 (possessing intact NSP1 gene) and either simian rotavirus SAff11 or human rotavirus KU. In coinfection with SAff11 and Aff5–13, selection rates of Aff5–13 segments in reassortants ranged approximately from 20 to 70% (46% for NSP1 gene). In contrast, in the reassortment between SAff11 and Aff5–10 or between SAff11 and Aff5–16, selection rates of NSP1 gene from Aff5–10 and Aff5–16 were only 1% (one clone) and 0%, respectively. In reassortants from crosses KU × Aff5-clones, selection rate of Aff5–13 NSP1 gene decreased to 15%, while 11 reassortants with Aff5–10 NSP1 gene (31%) and one reassortant with Aff5–16 NSP1 gene (2%) were isolated. Reassortants with Aff5–10 NSP1 possessed a single gene (segment 9 or 11) from KU in the genetic background of Aff5–10. One reassortant clone (cl-55) with Aff5–16 NSP1 gene possessed KU gene segments 3, 4, and 8–11. When single-step growth curves were compared, the reassortant cl-55 showed almost identical growth curve to that of KU, while KU showed a better replication than Aff5–16. These results indicated that although Aff5–10 or Aff5–16 NSP1 gene encoding the truncated NSP1 is selected into reassortants much less efficiently than normal NSP1 gene, the reassortants with the mutated NSP1 gene and RNA segments from heterologous strains normally replicated in cultured cells. Thus, cysteine-rich region of NSP1 was not considered essential for genome segment reassortment with heterologous virus.

Complete nucleotide sequence of the nonstructural gene of alphavirus YN87448 strain isolated in China and its relationship to other Sindbis viruses

Abstract: OBJECTIVE To determine the complete nucleotide sequence of the nonstructural gene of YN87448 virus stain which was firstly isolated from a female patient with fever in Yunnan Province in 1986, and identified as a member of Alphavirus by the serological method. METHODS The complete nucleotide sequence of the nonstructural region gene of YN87448 virus strain was determined with nine clones, which were obtained by using reverse transcription and polymerase chain reaction (RT-PCR), and by linking nine overlapping fragments into pGEM-T vector respectively. RESULTS The complete nucleotide sequence of nonstructural gene of YN87448 virus strain was 7,613 nucleotides long exclusive of the 5' cap, encoding four nonstructural proteins, nsP1, nsP2, nsP3, nsP4, and contained one initiator(ATG) and two stop codons (TGA). In comparison with the consensus sequence of S.A.AR86, the homogeneity of the nucleotide sequence between YN87448 virus strain and sindbis-like virus isolate S.A.AR86 was 98.8%. YN87448 virus strain can not produce a fatal disease in adult mice. In comparison with the consensus sequence of S.A.AR86, there is a 54 nucleotide insertion from 5,256 bp to 5,309 bp, 3 nucleotide (AGT) deletion at 5,603 bp in nsP3 region, and an opal termination codon between the nsP3 and the nsP4 genes in YN87448. virus strain. This sequence has been put into Gene Bank and No. is AF103734. CONCLUSION YN87448 is a new sindbis-like virus strain.