AIM： To investigate the inhibitory effect of VP22 fusion protein-based dominant negative （DN） mutant on Hepatitis Bvrus （HBV） replication. METHODS： Full-length or truncated fragment of VP22 was fused to C termin...AIM： To investigate the inhibitory effect of VP22 fusion protein-based dominant negative （DN） mutant on Hepatitis Bvrus （HBV） replication. METHODS： Full-length or truncated fragment of VP22 was fused to C terminal of HBV core protein （HBc）, and subcloned into pcDNA3.1 （-） vector, yielding eukaryotic expression plasmids of DN mutant. After transfection into HepG2.2.15 cells, the expression of DN mutant was identified by immunofluorescence staining. The inhibitory effect of DN mutant on HBV replication was indexed as the supernatant HBsAg concentration determined by RIA and HBV-DNA content by fluorescent quantification-PCR （FQ-PCR）. Meanwhile, metabolism of HepG2.2.25 cells was evaluated by MTI- colorimetry. RESULTS： VP22-based DN mutants and its truncated fragment were expressed in HepG2.2.15 cells, and had no toxic effect on host cells. DN mutants could inhibit HBV replication and the transduction ability of mutantbearing protein had a stronger inhibitory effect on HBV replication. DN mutants with full length of VP22 had the strongest inhibitory effect on HBV replication, reducing the HBsAg concentration by 81.94%, and the HBV-DNA content by 72.30%. MTT assay suggested that there were no significant differences in cell metabolic activity between the groups. CONCLUSION： VP22-based DN mutant can inhibit HBV replication effectively.展开更多
In the winter of 1997, a semi-dwarf mutant was found inthe F6 population of M9056/ R8018 xuan in HainanProvince. In the spring of 1998, the seeds were sown inHefei, Anhui Province and the plant height of the popula-ti...In the winter of 1997, a semi-dwarf mutant was found inthe F6 population of M9056/ R8018 xuan in HainanProvince. In the spring of 1998, the seeds were sown inHefei, Anhui Province and the plant height of the popula-tion was measured at maturity. Results showed that29. 4% of the plants had the same height as the high par-ent had, and 70. 6% remained semi-dwarf. In the winterof 1998, the reciprocal crosses between the remained se-mi-dwarf line and the two wild-type parental lines were展开更多
Mouse NANOG plays a critical role in maintaining self-renewal and pluripotency of embryonic stem cells.Yet,the precise mechanism of how mNANOG functions is still less known.Here,we report that mouse NANOG has two nucl...Mouse NANOG plays a critical role in maintaining self-renewal and pluripotency of embryonic stem cells.Yet,the precise mechanism of how mNANOG functions is still less known.Here,we report that mouse NANOG has two nuclear localization signals(NLS,RKQKMR and RMKCKR) which are responsible for the nuclear localization and transcriptional activity in the conserved homeobox domain.NLS mutants of mouse NANOG generate 3 mutants that are localized throughout the cells and lose the transactivation function.We further prove that all three NLS mutants may interact with the wild-type mouse NANOG like NANOG dimerization itself and inhibit the wild-type mouse NANOG activity,acting as dominant negative mutants.The NLS mutants of mouse NANOG may also inhibit activity of oct4 promoter in pluripotent cells,indicating that the NLS mutants can affect the endogenous mouse NANOG function in vivo.These data suggest that the NLS mutants of mouse NANOG may be used as a tool to regulate NANOG activity in pluripotent cells.展开更多
基金Supported by the National Natural Science Foundation of China,No. 30400380
文摘AIM： To investigate the inhibitory effect of VP22 fusion protein-based dominant negative （DN） mutant on Hepatitis Bvrus （HBV） replication. METHODS： Full-length or truncated fragment of VP22 was fused to C terminal of HBV core protein （HBc）, and subcloned into pcDNA3.1 （-） vector, yielding eukaryotic expression plasmids of DN mutant. After transfection into HepG2.2.15 cells, the expression of DN mutant was identified by immunofluorescence staining. The inhibitory effect of DN mutant on HBV replication was indexed as the supernatant HBsAg concentration determined by RIA and HBV-DNA content by fluorescent quantification-PCR （FQ-PCR）. Meanwhile, metabolism of HepG2.2.25 cells was evaluated by MTI- colorimetry. RESULTS： VP22-based DN mutants and its truncated fragment were expressed in HepG2.2.15 cells, and had no toxic effect on host cells. DN mutants could inhibit HBV replication and the transduction ability of mutantbearing protein had a stronger inhibitory effect on HBV replication. DN mutants with full length of VP22 had the strongest inhibitory effect on HBV replication, reducing the HBsAg concentration by 81.94%, and the HBV-DNA content by 72.30%. MTT assay suggested that there were no significant differences in cell metabolic activity between the groups. CONCLUSION： VP22-based DN mutant can inhibit HBV replication effectively.
文摘In the winter of 1997, a semi-dwarf mutant was found inthe F6 population of M9056/ R8018 xuan in HainanProvince. In the spring of 1998, the seeds were sown inHefei, Anhui Province and the plant height of the popula-tion was measured at maturity. Results showed that29. 4% of the plants had the same height as the high par-ent had, and 70. 6% remained semi-dwarf. In the winterof 1998, the reciprocal crosses between the remained se-mi-dwarf line and the two wild-type parental lines were
基金Supported by National Natural Science Foundation of China (Grant Nos.30725012,30630039 and 90813033)Knowledge Innovation Project of Chinese Academy of Sciences (Grant No.KSCX2-YW-R-48)+1 种基金Guangzhou Science and Technology Commission Foundation (Grant No.2008A1-E4011)National Key Basic Research and Development Program of China (Grant Nos.2006CB701504,2006CB943600,2007CB948002 and 2007CB947804)
文摘Mouse NANOG plays a critical role in maintaining self-renewal and pluripotency of embryonic stem cells.Yet,the precise mechanism of how mNANOG functions is still less known.Here,we report that mouse NANOG has two nuclear localization signals(NLS,RKQKMR and RMKCKR) which are responsible for the nuclear localization and transcriptional activity in the conserved homeobox domain.NLS mutants of mouse NANOG generate 3 mutants that are localized throughout the cells and lose the transactivation function.We further prove that all three NLS mutants may interact with the wild-type mouse NANOG like NANOG dimerization itself and inhibit the wild-type mouse NANOG activity,acting as dominant negative mutants.The NLS mutants of mouse NANOG may also inhibit activity of oct4 promoter in pluripotent cells,indicating that the NLS mutants can affect the endogenous mouse NANOG function in vivo.These data suggest that the NLS mutants of mouse NANOG may be used as a tool to regulate NANOG activity in pluripotent cells.
