Pea ( Pisum sativum Linn.) actin gene family contains at least three isoforms (PEAcⅠ, PEAcⅡand PEAcⅢ), and the DNA sequence of these isoforms show high similarity in the coding regions and significant divergence...Pea ( Pisum sativum Linn.) actin gene family contains at least three isoforms (PEAcⅠ, PEAcⅡand PEAcⅢ), and the DNA sequence of these isoforms show high similarity in the coding regions and significant divergence in the untranslated regions. RT_PCR and Southern blotting using 3′_untranslated region (3′_UTR) as specific probe revealed that pea isoactin genes were expressed in roots, stems, leaves, tendrils, pollen and juvenile siliques, but displayed different patterns of transcript accumulation. Two_fold serial dilution electrophoresis showed PEAcⅠ mRNA preferentially accumulated in rapidly developing tissues: it peaked in seven days' stem; remained at a rather high level in leaves within a month but decreased significantly later; varied a little in tendrils and reached a median and a very low level respectively in juvenile siliques and in pollen. PEAcⅡ displayed somewhat similar expression pattern to PEAcⅠ. The observed differences in sequences and transcript accumulation patterns suggest that the individual pea actin genes may differ in their transcriptional regulation and cellular function. Phylogenetic tree of actins showed that pea actin isoforms are as diverged from each other as they are from other plant actins, and pea actins might have originated from a common ancestor before the divergence of the dicot and monocot plants.展开更多
[Objective] The research aimed to provide reference for increasing the genetic transformation efficiency of Ginkgo biloba mediated by Agrobacterium.[Method] Taking the mature embryos of Ginkgo biloba seeds as explants...[Objective] The research aimed to provide reference for increasing the genetic transformation efficiency of Ginkgo biloba mediated by Agrobacterium.[Method] Taking the mature embryos of Ginkgo biloba seeds as explants,after 48 hours' pre-cultivation on MS medium in the absence of phytohormone,GUS gene was transmitted into embryos of Ginkgo biloba mediated by three kinds of Agrobacterium.Transient expression of GUS gene activity was observed through histochemical staining,and the influencing factors of the expression of GUS gene were analyzed.And the expression vector of 1-deoxy-D-xylulose-5-phosphate reductoisomerase in the biosynthesis approach of biobalide precursor of Ginkgo biloba was constructed.[Result] A more suitable genetic transformation scheme was obtained as follows:taking embryos of Ginkgo biloba as explants,using EHA105 Agrobacterium with pCAMBIA1304+ for infection,co-culture for 3 days and GUS staining.The results showed that transient expression rate of GUS after transformation was higher.[Conclusion] The research provide a more effective method for further study on the transgene of Ginkgo biloba.展开更多
AIM: TO determine the DNA binding activity and protein levels of the Ku70/80 heterodimer, the functional mediator of the NHEJ activity, in human colorectal carcinogenesis. METHODS: The Ku70/80 DNA-binding activity w...AIM: TO determine the DNA binding activity and protein levels of the Ku70/80 heterodimer, the functional mediator of the NHEJ activity, in human colorectal carcinogenesis. METHODS: The Ku70/80 DNA-binding activity was determined by electrophoretic mobility shift assays in 20 colon adenoma and 15 colorectal cancer samples as well as matched normal colonic tissues. Nuclear and cytoplasmic protein expression was determined by immunohistochemistry and Western blot analysis. RESULTS: A statistical found in both adenomas y significant difference was and carcinomas as compared to matched normal colonic mucosa (P〈0.00). However, changes in binding activity were not homogenous with approximately 50% of the tumors showing a clear increase in the binding activity, 30% displaying a modest increase and 15% showing a decrease of the activity.Tumors, with increased DNA-binding activity, also showed a statistically significant increase in Ku70 and Ku86 nuclear expression, as determined by Western blot and immunohistochemical analyses (P〈0.001). Cytoplasmic protein expression was found in pathological samples, but not in normal tissues either from tumor patients or from healthy subjects. CONCLUSION: Overall, our DNA-binding activity and protein level are consistent with a substantial activation of the NHEJ pathway in colorectal tumors. Since the NHEJ is an error prone mechanism, its abnormal activation can result in chromosomal instability and ultimately lead to tumorigenesis.展开更多
Objective. To evaluate the possibility and efficiency of nanoparticle as a new vector in specific gene transference.Methods. Nanoparticle-DNA complex was prepared with Poly- dl-lactic-co-glycolic acid (PLGA) bearing a...Objective. To evaluate the possibility and efficiency of nanoparticle as a new vector in specific gene transference.Methods. Nanoparticle-DNA complex was prepared with Poly- dl-lactic-co-glycolic acid (PLGA) bearing anti-sense monocyte chemotactic protein-1 (A-MCP-l), a specific expression gene, and the package efficiency, release progress in vitro, and the size of the complex were determined. The possibility of the new vector was evaluated with genomic DNA PCR by transferring gene into cultured smooth muscle cells (SMC), cationic lipids as a control. For study in vivo, jugular vein-to-artery bypass grafting procedures were performed on 20 New Zealand white rabbits, of which 6 grafts were transferred with nanoparticle-A-MCP-1 (200 μg), 6 with A - MCP-1 (200 μ g) by cationic liposome, 4 with LNCX plasmid, and 4 as control. Fourteen days after the grafts were harvested, the expression of A-MCP-l and its effect on MCP-1 in vein grafts were detected by dot blot, and the morphologic evaluation of grafts was performed.Results. The package efficiency of the nanoparticle-DNA complex was 0. 9% , release progress in vitro lasted 2 weeks, and the size ranged from 150 to 300nm. SMC genomic DNA PCR showed that A-MCP-l gene could be successfully transfected into cells by nanoparticle. The study in vivo indicated that A-MCP-l mRNA was expressed in both local gene delivery groups, nanoparticle and liposome, meanwhile, MCP-1 expression in vein grafts was significantly inhibited and neointimal hyperplasia was notably reduced.Conclusion. Nanoparticle can act as a vector to transfect specific gene.展开更多
OBJECTIVE To investigate the putative role of the Notch1 receptor in cervical cancer carcinogenesis and progression. METHODS The expression of the Notch1 protein was analyzed by a Western-blotting approach in 40 cervi...OBJECTIVE To investigate the putative role of the Notch1 receptor in cervical cancer carcinogenesis and progression. METHODS The expression of the Notch1 protein was analyzed by a Western-blotting approach in 40 cervical cancer and 30 normal cervical tissues. Some tissues were examined using RT-PCR to determine mRNA levels. Celluar localization of the Notch1 protein in the paraffin-embedded cervical tissues was also analyzed by immunohistochemistry. RESULTS The Notch1 protein was detected in all 30 normal cervical tissues. In contrast, only 6 samples of 40 cervical cancer tissues showed Notch1 expression. The level of the Notch1 protein expression was significantly lower in cervical cancer tissues than that in normal tissue samples. In agreement with these observations, levels of Notch1 mRNA were found to be substantially down-regulated in cervical cancer tissues. In the immunohistochemistry staining assay, the Notch1 protein was shown to localize predominantly in the cytoplasm and nucleoli of the normal cervical squamous epithelium of the cervix, but no staining was observed in the cervical cancer cells. Notch1 expression was observed to correlate with the clinical disease stage, but there were no correlations with age, tumor size, grade or lymph node metastasis (P〉0.05). The levels of Notch1 protein expression were significantly higher in early stages (Ⅰ-Ⅱa, 66.7%) compared to those in the advanced stages (Ⅱb~Ⅳ,12.6%)(P=0.001). CONCLUSION Notch1 may play a role as a tumor suppressor in cervical tumorigenesis. Determination of Notch1 expression may be helpful for preoperative diagnosis and accuracy of staging. But its clinical use for cervical cancer requires further investigation.展开更多
To better know FM (Fusarium moniliforme) induced genes in maize ear rot, GO (gene ontology) method was performed to analyze detail physiological functions in the defensive response after pathogen infection. This g...To better know FM (Fusarium moniliforme) induced genes in maize ear rot, GO (gene ontology) method was performed to analyze detail physiological functions in the defensive response after pathogen infection. This gene annotation system was widely used to investigate large numbers of genes involving in real active role or regulator in cell response. First of all, differentially expressed genes were isolated by using genechip platform at 96 h post-inoculation with FM in maize inbred Bt-1. In total, 482 differentially expressed unique genes were screened out in inbred Bt-1 when compared to mock-inoculated bract tissues. Then, each gene was annotated to define functional class by GO method. Finally, these large FM-responsive genes with significant differentially change were sorted into cellular component, molecular function and biological process with complicated network by molecular annotation system. The demonstrated information in the GO analysis could provide another view for understanding the molecular mechanism and indicate a deeply complicated network with gene function underlying disease development in the host tissue. The findings in this study provide important bases to probe the molecular processes, the alteration of metabolism and the immune mechanism upon the FM infection in maize.展开更多
The receptor for autocrine motility factor (AMFR) is known to be involved in the process of AMF-mediated cell migration and metastasis. This paper describes the procedures of non-radioactive in situ hybridization (ISH...The receptor for autocrine motility factor (AMFR) is known to be involved in the process of AMF-mediated cell migration and metastasis. This paper describes the procedures of non-radioactive in situ hybridization (ISH) detection of AMFR mRNA in both paraffin-embedded surgical sections and cultured cells using either biotinylated oligonucleotide probes or digoxigenin-labeled RNA probes. The results showed that the AMFR mRNA was expressed at an enhanced level in hyperplaJstic and malignant tissues of breast and prostate cancer patient surgical specimens, indicating that the elevated AMFR expression was associated with the tissue malignancy Moreover, AMFR mRNA was detected in both normal and earcinoma cells when cultured at a subconfluent density. However, AMFR expression was inhibited in confluent normal (3T3-A31 murine fibroblast and FHs738BL human bladder) cells while it continued to express in carcinoma (J82 human bladder)and metastatic (3T3-M murine fibroblast) cells irrespective of cell density This suggested a cell-cell contact downregulation of AMFR mRNA expression in normal but not in cancer cells. The ISH data obtained in this study are closely consistent with the AMFR protein expression pattern previously reported, implying that the differential expression of AMFR gene may be regulated and controlled at the transcriptional level.展开更多
The use of entomopathogenic fungi to control mosquitoes is a promising tool for reducing vector-borne disease transmission. To better understand infection stratagems of insect pathogenic fungi, we analyzed the global ...The use of entomopathogenic fungi to control mosquitoes is a promising tool for reducing vector-borne disease transmission. To better understand infection stratagems of insect pathogenic fungi, we analyzed the global gene expression profiling of Beauveria bassiana at 36, 60, 84 and 108 h after topical infection of Anopheles stephensi adult mosquitoes using RNA sequencing (RNA-Seq). A total of 5,354 differentially expressed genes (DEGs) are identified over the course of fungal infection. When the fungus grows on the mosquito cuticle, up-regulated DEGs include adhesion-related genes involved in cuticle attachment, Pthl l-like GPCRs hypothesized to be involved in host recognition, and extracellular enzymes involved in the degradation and penetration of the mosquito cuticle. Once in the mosquito hemocoel, the fungus evades mosquito immune system probably through up-regulating expression of 13-1,3-glucan degrading enzymes and chitin synthesis enzymes for remodeling of cell walls. Moreover, six previous unknown SSCP (small secreted cysteine-rich proteins) are significantly up-regulated, which may serve as "effectors" to suppress host defense responses. B. bassiana also induces large amounts of antioxidant genes to mitigate host-generated exogenous oxidative stress. At late stage of infection, B. bassiana activates a broad spectrum of genes including nutrient degrading enzymes, some transporters and metabolism pathway components, to exploit mosquito tissues and hemolymph as a nutrient source for hyphal growth. These findings establish an important framework of knowledge for further comprehensive elucidation of fungal pathogenesis and molecular mechanism of Beauveria-mosquito interactions.展开更多
The inclusion membrane proteins play potentially important roles in chlamydial biology and pathogenesis.Here we localized and characterized the hypothetical protein CT440 in Chlamydia trachomatis-infected cells.The op...The inclusion membrane proteins play potentially important roles in chlamydial biology and pathogenesis.Here we localized and characterized the hypothetical protein CT440 in Chlamydia trachomatis-infected cells.The open reading frame(ORF) encoding the CT440 protein from the C.trachomatis serovar D genome was cloned into the prokaryotic expression vector pGEX-6p and expressed as a glutathione-S-transferase(GST) fusion protein in E.coli XL1-Blue.The CT440 fusion protein was used to immunize mice to raise antigen-specific antibody.After verification by Western blot and immunofluorescence assay(IFA),the specific antibody was used to localize the endogenous CT440 protein and to detect its expression pattern in Chlamydia-infected cells.Cytosolic expression of CT440 in HeLa cells was also carried out to evaluate the effect of the CT440 protein on the subsequent chlamydial infection.The results showed that the hypothetical protein CT440 was localized in the C.trachomatis inclusion membrane,and was detectable 12 h after chlamydial infection.Expression of CT440 in the cytoplasm did not inhibit the subsequent chlamydial infection.In summary,we have identified a new inclusion membrane protein that may be an important candidate for understanding C.trachomatis pathogenesis.展开更多
We investigate theoretically the intervalley plasmon excitations(IPEs) in graphene monolayer within the random-phase approximation. We derive an analytical expression of the real part of the dielectric function. We fi...We investigate theoretically the intervalley plasmon excitations(IPEs) in graphene monolayer within the random-phase approximation. We derive an analytical expression of the real part of the dielectric function. We find a lowenergy plasmon mode with a linear anisotropic dispersion which depends on the Fermi energy and the dielectric constant of substrate. The IPEs show strongly anisotropic behavior, which becomes significant around the zigzag crystallographic direction. More interestingly, the group velocity of IPE varies from negative to positive, and vanishes at special energy.展开更多
文摘Pea ( Pisum sativum Linn.) actin gene family contains at least three isoforms (PEAcⅠ, PEAcⅡand PEAcⅢ), and the DNA sequence of these isoforms show high similarity in the coding regions and significant divergence in the untranslated regions. RT_PCR and Southern blotting using 3′_untranslated region (3′_UTR) as specific probe revealed that pea isoactin genes were expressed in roots, stems, leaves, tendrils, pollen and juvenile siliques, but displayed different patterns of transcript accumulation. Two_fold serial dilution electrophoresis showed PEAcⅠ mRNA preferentially accumulated in rapidly developing tissues: it peaked in seven days' stem; remained at a rather high level in leaves within a month but decreased significantly later; varied a little in tendrils and reached a median and a very low level respectively in juvenile siliques and in pollen. PEAcⅡ displayed somewhat similar expression pattern to PEAcⅠ. The observed differences in sequences and transcript accumulation patterns suggest that the individual pea actin genes may differ in their transcriptional regulation and cellular function. Phylogenetic tree of actins showed that pea actin isoforms are as diverged from each other as they are from other plant actins, and pea actins might have originated from a common ancestor before the divergence of the dicot and monocot plants.
文摘[Objective] The research aimed to provide reference for increasing the genetic transformation efficiency of Ginkgo biloba mediated by Agrobacterium.[Method] Taking the mature embryos of Ginkgo biloba seeds as explants,after 48 hours' pre-cultivation on MS medium in the absence of phytohormone,GUS gene was transmitted into embryos of Ginkgo biloba mediated by three kinds of Agrobacterium.Transient expression of GUS gene activity was observed through histochemical staining,and the influencing factors of the expression of GUS gene were analyzed.And the expression vector of 1-deoxy-D-xylulose-5-phosphate reductoisomerase in the biosynthesis approach of biobalide precursor of Ginkgo biloba was constructed.[Result] A more suitable genetic transformation scheme was obtained as follows:taking embryos of Ginkgo biloba as explants,using EHA105 Agrobacterium with pCAMBIA1304+ for infection,co-culture for 3 days and GUS staining.The results showed that transient expression rate of GUS after transformation was higher.[Conclusion] The research provide a more effective method for further study on the transgene of Ginkgo biloba.
基金Supported by Italian Ministero della Salute, IRCCS, RC0302TG13 by Ministero dell'Istruzíone, Università e Ricerca scientifica e tecnologica (MIUR), COFIN2002, to the Universita Campus Bio-Medico
文摘AIM: TO determine the DNA binding activity and protein levels of the Ku70/80 heterodimer, the functional mediator of the NHEJ activity, in human colorectal carcinogenesis. METHODS: The Ku70/80 DNA-binding activity was determined by electrophoretic mobility shift assays in 20 colon adenoma and 15 colorectal cancer samples as well as matched normal colonic tissues. Nuclear and cytoplasmic protein expression was determined by immunohistochemistry and Western blot analysis. RESULTS: A statistical found in both adenomas y significant difference was and carcinomas as compared to matched normal colonic mucosa (P〈0.00). However, changes in binding activity were not homogenous with approximately 50% of the tumors showing a clear increase in the binding activity, 30% displaying a modest increase and 15% showing a decrease of the activity.Tumors, with increased DNA-binding activity, also showed a statistically significant increase in Ku70 and Ku86 nuclear expression, as determined by Western blot and immunohistochemical analyses (P〈0.001). Cytoplasmic protein expression was found in pathological samples, but not in normal tissues either from tumor patients or from healthy subjects. CONCLUSION: Overall, our DNA-binding activity and protein level are consistent with a substantial activation of the NHEJ pathway in colorectal tumors. Since the NHEJ is an error prone mechanism, its abnormal activation can result in chromosomal instability and ultimately lead to tumorigenesis.
基金This program was supported by the National Natural Sciences Foundation of China (No. 39870196).
文摘Objective. To evaluate the possibility and efficiency of nanoparticle as a new vector in specific gene transference.Methods. Nanoparticle-DNA complex was prepared with Poly- dl-lactic-co-glycolic acid (PLGA) bearing anti-sense monocyte chemotactic protein-1 (A-MCP-l), a specific expression gene, and the package efficiency, release progress in vitro, and the size of the complex were determined. The possibility of the new vector was evaluated with genomic DNA PCR by transferring gene into cultured smooth muscle cells (SMC), cationic lipids as a control. For study in vivo, jugular vein-to-artery bypass grafting procedures were performed on 20 New Zealand white rabbits, of which 6 grafts were transferred with nanoparticle-A-MCP-1 (200 μg), 6 with A - MCP-1 (200 μ g) by cationic liposome, 4 with LNCX plasmid, and 4 as control. Fourteen days after the grafts were harvested, the expression of A-MCP-l and its effect on MCP-1 in vein grafts were detected by dot blot, and the morphologic evaluation of grafts was performed.Results. The package efficiency of the nanoparticle-DNA complex was 0. 9% , release progress in vitro lasted 2 weeks, and the size ranged from 150 to 300nm. SMC genomic DNA PCR showed that A-MCP-l gene could be successfully transfected into cells by nanoparticle. The study in vivo indicated that A-MCP-l mRNA was expressed in both local gene delivery groups, nanoparticle and liposome, meanwhile, MCP-1 expression in vein grafts was significantly inhibited and neointimal hyperplasia was notably reduced.Conclusion. Nanoparticle can act as a vector to transfect specific gene.
文摘OBJECTIVE To investigate the putative role of the Notch1 receptor in cervical cancer carcinogenesis and progression. METHODS The expression of the Notch1 protein was analyzed by a Western-blotting approach in 40 cervical cancer and 30 normal cervical tissues. Some tissues were examined using RT-PCR to determine mRNA levels. Celluar localization of the Notch1 protein in the paraffin-embedded cervical tissues was also analyzed by immunohistochemistry. RESULTS The Notch1 protein was detected in all 30 normal cervical tissues. In contrast, only 6 samples of 40 cervical cancer tissues showed Notch1 expression. The level of the Notch1 protein expression was significantly lower in cervical cancer tissues than that in normal tissue samples. In agreement with these observations, levels of Notch1 mRNA were found to be substantially down-regulated in cervical cancer tissues. In the immunohistochemistry staining assay, the Notch1 protein was shown to localize predominantly in the cytoplasm and nucleoli of the normal cervical squamous epithelium of the cervix, but no staining was observed in the cervical cancer cells. Notch1 expression was observed to correlate with the clinical disease stage, but there were no correlations with age, tumor size, grade or lymph node metastasis (P〉0.05). The levels of Notch1 protein expression were significantly higher in early stages (Ⅰ-Ⅱa, 66.7%) compared to those in the advanced stages (Ⅱb~Ⅳ,12.6%)(P=0.001). CONCLUSION Notch1 may play a role as a tumor suppressor in cervical tumorigenesis. Determination of Notch1 expression may be helpful for preoperative diagnosis and accuracy of staging. But its clinical use for cervical cancer requires further investigation.
基金Acknowledgments This research was supported by the Natural National Science Foundation of China (No. 30571173, No. 31201274), National High Technology Research and Development Program of China (863 Program) (No. 2012AA10A307).
文摘To better know FM (Fusarium moniliforme) induced genes in maize ear rot, GO (gene ontology) method was performed to analyze detail physiological functions in the defensive response after pathogen infection. This gene annotation system was widely used to investigate large numbers of genes involving in real active role or regulator in cell response. First of all, differentially expressed genes were isolated by using genechip platform at 96 h post-inoculation with FM in maize inbred Bt-1. In total, 482 differentially expressed unique genes were screened out in inbred Bt-1 when compared to mock-inoculated bract tissues. Then, each gene was annotated to define functional class by GO method. Finally, these large FM-responsive genes with significant differentially change were sorted into cellular component, molecular function and biological process with complicated network by molecular annotation system. The demonstrated information in the GO analysis could provide another view for understanding the molecular mechanism and indicate a deeply complicated network with gene function underlying disease development in the host tissue. The findings in this study provide important bases to probe the molecular processes, the alteration of metabolism and the immune mechanism upon the FM infection in maize.
文摘The receptor for autocrine motility factor (AMFR) is known to be involved in the process of AMF-mediated cell migration and metastasis. This paper describes the procedures of non-radioactive in situ hybridization (ISH) detection of AMFR mRNA in both paraffin-embedded surgical sections and cultured cells using either biotinylated oligonucleotide probes or digoxigenin-labeled RNA probes. The results showed that the AMFR mRNA was expressed at an enhanced level in hyperplaJstic and malignant tissues of breast and prostate cancer patient surgical specimens, indicating that the elevated AMFR expression was associated with the tissue malignancy Moreover, AMFR mRNA was detected in both normal and earcinoma cells when cultured at a subconfluent density. However, AMFR expression was inhibited in confluent normal (3T3-A31 murine fibroblast and FHs738BL human bladder) cells while it continued to express in carcinoma (J82 human bladder)and metastatic (3T3-M murine fibroblast) cells irrespective of cell density This suggested a cell-cell contact downregulation of AMFR mRNA expression in normal but not in cancer cells. The ISH data obtained in this study are closely consistent with the AMFR protein expression pattern previously reported, implying that the differential expression of AMFR gene may be regulated and controlled at the transcriptional level.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences(XDB11010500)National Key R&D Program of China(2017YFD0200400,SQ2017ZY060066)the Hundred Talents Program of the Chinese Academy of Sciences
文摘The use of entomopathogenic fungi to control mosquitoes is a promising tool for reducing vector-borne disease transmission. To better understand infection stratagems of insect pathogenic fungi, we analyzed the global gene expression profiling of Beauveria bassiana at 36, 60, 84 and 108 h after topical infection of Anopheles stephensi adult mosquitoes using RNA sequencing (RNA-Seq). A total of 5,354 differentially expressed genes (DEGs) are identified over the course of fungal infection. When the fungus grows on the mosquito cuticle, up-regulated DEGs include adhesion-related genes involved in cuticle attachment, Pthl l-like GPCRs hypothesized to be involved in host recognition, and extracellular enzymes involved in the degradation and penetration of the mosquito cuticle. Once in the mosquito hemocoel, the fungus evades mosquito immune system probably through up-regulating expression of 13-1,3-glucan degrading enzymes and chitin synthesis enzymes for remodeling of cell walls. Moreover, six previous unknown SSCP (small secreted cysteine-rich proteins) are significantly up-regulated, which may serve as "effectors" to suppress host defense responses. B. bassiana also induces large amounts of antioxidant genes to mitigate host-generated exogenous oxidative stress. At late stage of infection, B. bassiana activates a broad spectrum of genes including nutrient degrading enzymes, some transporters and metabolism pathway components, to exploit mosquito tissues and hemolymph as a nutrient source for hyphal growth. These findings establish an important framework of knowledge for further comprehensive elucidation of fungal pathogenesis and molecular mechanism of Beauveria-mosquito interactions.
基金supported by the National Natural Science Foundation of China (Grant Nos. 30970165 and 81102230)the Hunan Provincial Natu-ral Science Foundation of China (Grant No. 09JJ3059)the Team Project for the Technology Innovation of Higher Education of Hunan Province,China
文摘The inclusion membrane proteins play potentially important roles in chlamydial biology and pathogenesis.Here we localized and characterized the hypothetical protein CT440 in Chlamydia trachomatis-infected cells.The open reading frame(ORF) encoding the CT440 protein from the C.trachomatis serovar D genome was cloned into the prokaryotic expression vector pGEX-6p and expressed as a glutathione-S-transferase(GST) fusion protein in E.coli XL1-Blue.The CT440 fusion protein was used to immunize mice to raise antigen-specific antibody.After verification by Western blot and immunofluorescence assay(IFA),the specific antibody was used to localize the endogenous CT440 protein and to detect its expression pattern in Chlamydia-infected cells.Cytosolic expression of CT440 in HeLa cells was also carried out to evaluate the effect of the CT440 protein on the subsequent chlamydial infection.The results showed that the hypothetical protein CT440 was localized in the C.trachomatis inclusion membrane,and was detectable 12 h after chlamydial infection.Expression of CT440 in the cytoplasm did not inhibit the subsequent chlamydial infection.In summary,we have identified a new inclusion membrane protein that may be an important candidate for understanding C.trachomatis pathogenesis.
基金Supported by the National Basic Research Program of China(973 Program)under Grant No.2013CB934001the State Key Laboratory of Software Development Environment under Grant No.SKLSDE-2013ZX-28
文摘We investigate theoretically the intervalley plasmon excitations(IPEs) in graphene monolayer within the random-phase approximation. We derive an analytical expression of the real part of the dielectric function. We find a lowenergy plasmon mode with a linear anisotropic dispersion which depends on the Fermi energy and the dielectric constant of substrate. The IPEs show strongly anisotropic behavior, which becomes significant around the zigzag crystallographic direction. More interestingly, the group velocity of IPE varies from negative to positive, and vanishes at special energy.