Nuclear proteins often form punctiform structures, but the precise mechanism for this process is unknown. As a preliminary study, we investigated the aggregation of an HSV-1 immediate-early protein, infected-cell prot...Nuclear proteins often form punctiform structures, but the precise mechanism for this process is unknown. As a preliminary study, we investigated the aggregation of an HSV-1 immediate-early protein, infected-cell protein 22 (ICP22), in the nucleus by observing the localization of ICP22-EGFP fusion protein Results showed that, in high-level expression conditions, ICP22-EGFP gradually concentrates in the nucleus, persists throughout the cell cycle without disaggregation even in the cell division phase, and is finally distributed to daughter cells. We subsequently constructed a mammalian cell expression system, which had tetracycline- dependent transcriptional regulators. Consequently, the location of ICP22-EGFP in the nucleus changed with distinct induction conditions. This suggests that the cellular location of ICP22 is also influenced by promoter regulation, in addition to its own structure. Our findings provide new clues for the investigation of transcriptional regulation of viral genes. In addition, the non-protease reporter system we constructed could be utilized to evaluate the role of intemal ribosome entry sites (IRES) on transcriptional regulation.展开更多
Au-Ft,as a green synthesized nanoparticle,is composed of a ferritin nanocage enclosing a pair of Au nanoclusters inside.Our previous study has demonstrated that Au-Ft can be an excellentfluorescent probe for whole bod...Au-Ft,as a green synthesized nanoparticle,is composed of a ferritin nanocage enclosing a pair of Au nanoclusters inside.Our previous study has demonstrated that Au-Ft can be an excellentfluorescent probe for whole body imaging of mice with kidney specific targeting.But,the accuratelocalization of Au-Ft in kidney is still absent.In the current study,we detected and assessed the cellular and subcellular localization of Au-Ft in renal cortex and medulla of nu/nu mice after tailvein injection by using Nuance optical system(CRi,Woburn,USA)and inForm intelligent image analysis soft ware based on single cell segmentation.We obtained the fluorescence intensity and cellular location of kidney-targeting Au-Ft probe in particular cell of renal glomerulus or renaltubules,which provided valuable proofs to clarify the mechanism of Au-Ft selective enrichment in kidney and the associated metabolic processes.展开更多
The rice pattern recognition receptor (PRR) XA21 confers race-specific resistance in leaf infection by bacterial blight Xathornonas oryzae pv. oryzae (Xoo), and was shown to be primarily localized to the endoplasm...The rice pattern recognition receptor (PRR) XA21 confers race-specific resistance in leaf infection by bacterial blight Xathornonas oryzae pv. oryzae (Xoo), and was shown to be primarily localized to the endoplasmic reticulum (ER) when expressed with its native promoter or overexpressed in the protoplast. However, whether the protein is still ER- localization in the intact cell when overexpressed remains to be identified. Here, we showed that XA21, its kinase-dead mutant XA21PK736EP and the triple autophosphorylation mutant XA21PS686AJT688AJS699A GFP fusions were primarily localized to the plasma membrane (PM) when overexpressed in the intact transgenic rice cell, and also localized to the ER in the transgenic protoplast. The transgenic plants constitutively expressing the wild-type XA21 or its GFP fusion displayed racespecific resistance to Xoo at the adult and seedling stages. XA21 and XA21PK736EP could be internalized probably via the SCAMP-positive early endosomal compartment in the protoplast, suggesting that XA21 might be endocytosed to initiate resistance responses during pathogen infection. We also established a root infection system and demonstrated that XA21 also mediated race-specific resistance responses to Xoo in the root. Our current study provides an insight into the nature of the XA21-mediated resistance and a practical approach using the root cell system to further dissect the cellular signaling of the PRR during the rice-Xoo interaction.展开更多
Fasciclin family proteins have been identified as cell adhesion molecules in various organisms. In this study, a novel Magnaporthe oryzae fasciclin-like protein encoding gene, named MoFLP1, was isolated from a subtrac...Fasciclin family proteins have been identified as cell adhesion molecules in various organisms. In this study, a novel Magnaporthe oryzae fasciclin-like protein encoding gene, named MoFLP1, was isolated from a subtractive suppressive cDNA library and functionally analyzed. Sequence analysis showed that the MoFLP1 gene contains an open reading frame (ORF) of 1050 nucleotides encoding 349 amino acids with a calculated molecular weight of 35.85 kDa and a pI of 7.76. The deduced MoFLP1 protein contains a 17-amino acid secretion signal sequence and an 18-amino acid sequence with the characteristics of a glycosylphosphotidylinositol (GPI) anchor additional signal at its N- and C-terminuses, respectively. Potential N-glycosylation sites and domains involving cell adhesion were also identified in MoFLP1. Sequence analysis and subcellular localization by the expression of MoFLP1-GFP fusion construct in M. oryzae indicated that the MoFLP1 protein is probably localized on the vacuole membrane. Two MoFLP1 null mutants generated by targeted gene disruption exhibited marked reduction of conidiation, conidial adhesion, appressorium turgor, and pathogenicity. Our results indicate that fasciclin proteins play important roles in fungal de-velopment and pathogenicity in M. oryzae.展开更多
基金The National Natural Science Foundation of China (30670094, 30700028)the Ph.D. Programs Foundation of Ministry of Education of China (2006-0023008)
文摘Nuclear proteins often form punctiform structures, but the precise mechanism for this process is unknown. As a preliminary study, we investigated the aggregation of an HSV-1 immediate-early protein, infected-cell protein 22 (ICP22), in the nucleus by observing the localization of ICP22-EGFP fusion protein Results showed that, in high-level expression conditions, ICP22-EGFP gradually concentrates in the nucleus, persists throughout the cell cycle without disaggregation even in the cell division phase, and is finally distributed to daughter cells. We subsequently constructed a mammalian cell expression system, which had tetracycline- dependent transcriptional regulators. Consequently, the location of ICP22-EGFP in the nucleus changed with distinct induction conditions. This suggests that the cellular location of ICP22 is also influenced by promoter regulation, in addition to its own structure. Our findings provide new clues for the investigation of transcriptional regulation of viral genes. In addition, the non-protease reporter system we constructed could be utilized to evaluate the role of intemal ribosome entry sites (IRES) on transcriptional regulation.
文摘Au-Ft,as a green synthesized nanoparticle,is composed of a ferritin nanocage enclosing a pair of Au nanoclusters inside.Our previous study has demonstrated that Au-Ft can be an excellentfluorescent probe for whole body imaging of mice with kidney specific targeting.But,the accuratelocalization of Au-Ft in kidney is still absent.In the current study,we detected and assessed the cellular and subcellular localization of Au-Ft in renal cortex and medulla of nu/nu mice after tailvein injection by using Nuance optical system(CRi,Woburn,USA)and inForm intelligent image analysis soft ware based on single cell segmentation.We obtained the fluorescence intensity and cellular location of kidney-targeting Au-Ft probe in particular cell of renal glomerulus or renaltubules,which provided valuable proofs to clarify the mechanism of Au-Ft selective enrichment in kidney and the associated metabolic processes.
文摘The rice pattern recognition receptor (PRR) XA21 confers race-specific resistance in leaf infection by bacterial blight Xathornonas oryzae pv. oryzae (Xoo), and was shown to be primarily localized to the endoplasmic reticulum (ER) when expressed with its native promoter or overexpressed in the protoplast. However, whether the protein is still ER- localization in the intact cell when overexpressed remains to be identified. Here, we showed that XA21, its kinase-dead mutant XA21PK736EP and the triple autophosphorylation mutant XA21PS686AJT688AJS699A GFP fusions were primarily localized to the plasma membrane (PM) when overexpressed in the intact transgenic rice cell, and also localized to the ER in the transgenic protoplast. The transgenic plants constitutively expressing the wild-type XA21 or its GFP fusion displayed racespecific resistance to Xoo at the adult and seedling stages. XA21 and XA21PK736EP could be internalized probably via the SCAMP-positive early endosomal compartment in the protoplast, suggesting that XA21 might be endocytosed to initiate resistance responses during pathogen infection. We also established a root infection system and demonstrated that XA21 also mediated race-specific resistance responses to Xoo in the root. Our current study provides an insight into the nature of the XA21-mediated resistance and a practical approach using the root cell system to further dissect the cellular signaling of the PRR during the rice-Xoo interaction.
基金Project supported by the National Natural Science Foundation of China (No. 30870101)the Public Welfare Profession (Agricul-ture) Research Project (No. 200803008), China
文摘Fasciclin family proteins have been identified as cell adhesion molecules in various organisms. In this study, a novel Magnaporthe oryzae fasciclin-like protein encoding gene, named MoFLP1, was isolated from a subtractive suppressive cDNA library and functionally analyzed. Sequence analysis showed that the MoFLP1 gene contains an open reading frame (ORF) of 1050 nucleotides encoding 349 amino acids with a calculated molecular weight of 35.85 kDa and a pI of 7.76. The deduced MoFLP1 protein contains a 17-amino acid secretion signal sequence and an 18-amino acid sequence with the characteristics of a glycosylphosphotidylinositol (GPI) anchor additional signal at its N- and C-terminuses, respectively. Potential N-glycosylation sites and domains involving cell adhesion were also identified in MoFLP1. Sequence analysis and subcellular localization by the expression of MoFLP1-GFP fusion construct in M. oryzae indicated that the MoFLP1 protein is probably localized on the vacuole membrane. Two MoFLP1 null mutants generated by targeted gene disruption exhibited marked reduction of conidiation, conidial adhesion, appressorium turgor, and pathogenicity. Our results indicate that fasciclin proteins play important roles in fungal de-velopment and pathogenicity in M. oryzae.