RNA silencing is a conserved mechanism found ubiquitously in eukaryotic organisms.It has been used to regulate gene expression and development.In addition,RNA silencing serves as an important mechanism in plants' ...RNA silencing is a conserved mechanism found ubiquitously in eukaryotic organisms.It has been used to regulate gene expression and development.In addition,RNA silencing serves as an important mechanism in plants' defense against invasive nucleic acids,such as viruses,transposons,and transgenes.As a counter-defense,most plants,and some animal viruses,encode RNA silencing suppressors to interfere at one or several points of the silencing pathway.In this study,we showed that Pns12 of RGDV (Rice gall dwarf virus) exhibits silencing suppressor activity on the reporter green fluorescent protein in transgenic Nicotiana benthamiana line 16c.Pns12 of RGDV suppressed local silencing induced by sense RNA but had no effect on that induced by dsRNA.Expression of Pns12 also enhanced Potato virus X pathogenicity in N.benthamiana.Collectively,these results suggested that RGDV Pns12 functions as a virus suppressor of RNA silencing,which might target an upstream step of dsRNA formation in the RNA silencing pathway.Furthermore,we showed that Pns12 is localized mainly in the nucleus of N.benthamiana leaf cells.展开更多
Archaea, along with Bacteria and Eukarya, are the three domains of life. In all living cells, chromatin proteins serve a crucial role in maintaining the integrity of the structure and function of the genome. An array ...Archaea, along with Bacteria and Eukarya, are the three domains of life. In all living cells, chromatin proteins serve a crucial role in maintaining the integrity of the structure and function of the genome. An array of small, abundant and basic DNA-binding proteins, considered candidates for chromatin proteins, has been isolated from the Euryarchaeota and the Crenarchaeota, the two major phyla in Archaea. While most euryarchaea encode proteins resembling eukaryotic histories, crenarchaea appear to synthesize a number of unique DNA-binding proteins likely involved in chromosomal organization. Several of these proteins （e.g., archaeal histones, Sacl0b homologs, Sul7d, Cren7, CC1, etc.） have been extensively studied. However, whether they are chromatin proteins and how they function in vivo remain to be fully understood. Future investiga- tion of archaeal chromatin proteins will lead to a better understanding of chromosomal organization and gene expression in Archaea and provide valuable information on the evolution of DNA packaging in cellular life.展开更多
基金supported by the National Basic Research Program of China(Grant No. 2010CB126203)the National Transgenic Major Program(Grant Nos. 2009ZX08009-044B and 2009ZX08001-018B)+2 种基金the National Natural Science Foundation of China(Grant No. 30970135)the Fujian Province Education Department(Grant No. JB08078)Specialized Research Fund for the Ministry of Agriculture(Grant No. nyhyzx07-051)
文摘RNA silencing is a conserved mechanism found ubiquitously in eukaryotic organisms.It has been used to regulate gene expression and development.In addition,RNA silencing serves as an important mechanism in plants' defense against invasive nucleic acids,such as viruses,transposons,and transgenes.As a counter-defense,most plants,and some animal viruses,encode RNA silencing suppressors to interfere at one or several points of the silencing pathway.In this study,we showed that Pns12 of RGDV (Rice gall dwarf virus) exhibits silencing suppressor activity on the reporter green fluorescent protein in transgenic Nicotiana benthamiana line 16c.Pns12 of RGDV suppressed local silencing induced by sense RNA but had no effect on that induced by dsRNA.Expression of Pns12 also enhanced Potato virus X pathogenicity in N.benthamiana.Collectively,these results suggested that RGDV Pns12 functions as a virus suppressor of RNA silencing,which might target an upstream step of dsRNA formation in the RNA silencing pathway.Furthermore,we showed that Pns12 is localized mainly in the nucleus of N.benthamiana leaf cells.
基金supported by the National Natural Science Foundation of ChinaMinistry of Science and TechnologyChinese Academy of Sciences
文摘Archaea, along with Bacteria and Eukarya, are the three domains of life. In all living cells, chromatin proteins serve a crucial role in maintaining the integrity of the structure and function of the genome. An array of small, abundant and basic DNA-binding proteins, considered candidates for chromatin proteins, has been isolated from the Euryarchaeota and the Crenarchaeota, the two major phyla in Archaea. While most euryarchaea encode proteins resembling eukaryotic histories, crenarchaea appear to synthesize a number of unique DNA-binding proteins likely involved in chromosomal organization. Several of these proteins （e.g., archaeal histones, Sacl0b homologs, Sul7d, Cren7, CC1, etc.） have been extensively studied. However, whether they are chromatin proteins and how they function in vivo remain to be fully understood. Future investiga- tion of archaeal chromatin proteins will lead to a better understanding of chromosomal organization and gene expression in Archaea and provide valuable information on the evolution of DNA packaging in cellular life.
