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Human astrovirus non-structural protein nsP1a/4, located at the C-terminal end of nsP1a, is thought to be involved in regulating RNA replication. Here, we show that host protein CD63 interacts with the nsP1a protein. Further research showed that the large loop (LEL) domain of CD63 also interacts with nsP1a/4. Confocal microscopy showed that nsP1a/4 protein and CD63 co-localized in the cytoplasm of co-transfected cells. Co-localization of nsP1a/4 and CD63 was also observed in HAstV-1-infected cells. Overexpression of CD63 promoted replication of HAstV-1, whereas knockdown of CD63 reduced production of HAstV-1 viral progeny. These results suggest that CD63 plays a critical role in HAstV-1 replication, and provide an avenue to further understanding the interactions between host and virus proteins during replication and pathogenesis of HAstV.

Human astrovirus nonstructural protein nsP1a/4, located at the C-terminal end of nsP1a, is thought to be involved in the regulation of RNA replication and capsid maturation;however, its rolesviral growth and virulence are not well understood. We investigated the intracellular host proteins that interact with nsP1a and explored the potential roles of the interaction in the pathogenesis of human astrovirus infection. We screened 14 independent proteins with a cDNA library derived from Caco-2 cells using a yeast two-hybrid technique. Deletion analysis revealed that interaction between the nsP1a/4 domain and the large extracellular loop (LEL) domain of the human protein CD63 is necessary for astrovirus replication. The interaction was confirmed by glutathione-S-transferase (GST) pull-down assays and co-immunoprecipitation assays. Confocal microscopy showed that nsP1a/4 and CD63 co-localized in the cytoplasm of infected cells. Over expression of CD63 promoted viral RNA synthesis, whereas knockdown of CD63 markedly decreased viral RNA levels. Those results suggest that CD63 plays a critical role in human astrovirus RNA replication. The interaction between CD63 and nsP1a/4 provides a channel to further understand the roles of interactions between host and virus proteins in astrovirus infection and release.IMPORTANCEHuman astroviruses cause gastroenteritis in young children and immunocompromised patients. In this study, we provide evidence that nsP1a/4, a nonstructural protein located at the C-terminal end of the human astrovirus nsP1a polyprotein, interacts with the host protein CD63. Over expression of CD63 promoted viral RNA replication, whereas knockdown of CD63 decreased virus RNA replication, indicating that CD63 plays a critical role in the human astrovirus life cycle.

Lactose intolerance in northern Europeans is strongly associated with a single-nucleotide polymorphism (SNP) located 14 kb upstream of the human lactase gene: -13,910 C/T. We examined whether SNPs in the 5' flanking region of the pig lactase gene are similar to those in the human gene and whether these polymorphisms play a functional role in regulating pig lactase gene expression. The 5' flanking region of the lactase gene from several different breeds of pigs was cloned and analyzed for gene regulatory activity of a luciferase reporter gene. One SNP was found in the enhancer region (-797 G/A) and two were found in the promoter region (-308G/C and -301 A/G). The promoter C-308,G-301(Pro-CG) strongly promotes the expression of the lactase gene, but the promoter G-308,A-301(Pro-GA) does not. The enhancer A-797(Enh-A) genotype for Pro-GA can significantly enhance promoter activity, but has an inhibitory effect on Pro-CG. The Enhancer G-797(Enh-G) has a significant inhibitory effect on both promoters. In conclusion, the order of effectiveness on the pig lactase gene is Enh-A+Pro-GA>Enh-A/G+Pro-CG>Enh-G+Pro-GA.

Wetlands play a number of roles in the environment, which are also considered the most biologically diverse of all ecosystems. Utilizing RS and the GIS software, remote datum were matched and classified. By these transactions, the temporal and spatial changes of wetland landscape are explored in Wuhu, combining qualitative analysis and quantitative methods. This paper analyzed the time-spatial revolution process which indicated that, firstly the area of wetland reduced rapidly from remote sensing image in 1988, 2001 and 2005, secondly the exterior of urban changed acutely and the interior were protected well in view of spatial pattern. Moreover, driving force factors were pointed out. Human activities, especially urbanization were the main causes of wetlands degradation. Simultaneity, the development of farming, the construction of infrastructure and nature were important factors. Owing to rapid economic development and urban sprawling, wetlands are encountering threaten to be converting to other land uses. Thus, the paper provides policy advices for wetland conservation and urban planning toward sustainable development.