Oestrogen is essential for maintaining bone mass, and it has been demonstrated to induce osteoblast proliferation and bone formation.In this study, complementary DNA（cDNA） microarrays were used to identify and study...Oestrogen is essential for maintaining bone mass, and it has been demonstrated to induce osteoblast proliferation and bone formation.In this study, complementary DNA（cDNA） microarrays were used to identify and study the expression of novel genes that may be involved in MC3T3-E1 cells’ response to 17-b estradiol. MC3T3-E1 cells were inoculated in minimum essential media alpha（a-MEM）cell culture supplemented with 17-b estradiol at different concentrations and for different time periods. MC3T3-E1 cells treated with1028mol？L2117-b estradiol for 5 days exhibited the highest proliferation and alkaline phosphatase（ALP） activity; thus, this group was chosen for microarray analysis. The harvested RNA was used for microarray hybridisation and subsequent real-time reverse transcription polymerase chain reaction（RT-PCR） to validate the expression levels for selected genes. The microarray results were analysed using both functional and pathway analysis. In this study, microarray analysis detected 5 403 differentially expressed genes,of which 1 996 genes were upregulated and 3 407 genes were downregulated, 1 553 different functional classifications were identified by gene ontology（GO） analysis and 53 different pathways were involved based on pathway analysis. Among the differentially expressed genes, a portion not previously reported to be associated with the osteoblast response to oestrogen was identified. These findings clearly demonstrate that the expression of genes related to osteoblast proliferation, cell differentiation, collagens and transforming growth factor beta（TGF-b）-related cytokines increases, while the expression of genes related to apoptosis and osteoclast differentiation decreases, following the exposure of MC3T3-E1 cells to a-MEM supplemented with 17-b estradiol. Microarray analysis with functional gene classification is critical for a complete understanding of complementary intracellular processes. This microarray analysis provides large-scale gene expression data that require further confirmatory studies.展开更多
Two-component systems are signal transduction systems which enable bacteria to regulate cellular functions in response to changing environmental conditions. The unicellular Synechocystis sp. PCC 6803 has become a mode...Two-component systems are signal transduction systems which enable bacteria to regulate cellular functions in response to changing environmental conditions. The unicellular Synechocystis sp. PCC 6803 has become a model organism for a range of biochemical and molecular biology studies aiming at investigating environmental stress response. The publication of the complete genome sequence of the cyanobacterium Synechocystis sp. PCC 6803 provided a tremendous stimulus for research in this field, and at least 80 open reading frames were identified as members of the two-component signal transduction systems in this single species of cyanobacteria. To date, functional roles have been determined for only a limited number of such proteins. This review summarizes our current knowledge about the two-component signal transduction systems in Synechocystis sp. PCC 6803 and describes recent achievements in elucidating the functional roles of these systems.展开更多
为了探索隐藏嗜酸菌(Acidiphilium cryptum)对多变极端矿山环境条件的感知和反应分子机制,预测和分析了隐藏嗜酸菌JF-5菌株的双组分信号转导系统(Two-component signal transduction system,TCS)的分布、结构及功能.鉴定了9对成对TCSs、...为了探索隐藏嗜酸菌(Acidiphilium cryptum)对多变极端矿山环境条件的感知和反应分子机制,预测和分析了隐藏嗜酸菌JF-5菌株的双组分信号转导系统(Two-component signal transduction system,TCS)的分布、结构及功能.鉴定了9对成对TCSs、2个杂合结构TCSs、3个孤儿组氨酸蛋白激酶(HK)和5个孤儿反应调节蛋白(RR);发现5个TCSs参与隐藏嗜酸菌对重金属响应转录调控;大多数HKs的N-末端具有接受信号的跨膜区、HAMP或PAS等结构域,RRs主要是OmpR亚家族,占总RRs的40%以上;从进化关系上来看,一些处在进化树同一分支上的共同聚簇TCS基因可能具有相同的进化途径.本研究结果可为研究隐藏嗜酸菌在极端环境中适应性分子机制提供新的方向.展开更多
Phosphorus is one of the macronutrients essential for plant growth and development. Many soils around the world are deficient in phosphate （Pi） which is the form of phosphorus that plants can absorb and utilize. To ...Phosphorus is one of the macronutrients essential for plant growth and development. Many soils around the world are deficient in phosphate （Pi） which is the form of phosphorus that plants can absorb and utilize. To cope with the stress of Pi starvation, plants have evolved many elaborate strategies to enhance the acquisition and utilization of Pi from the environment. These strategies include morphological, biochemical and physiological responses which ultimately enable plants to better survive under low Pi conditions. Though these adaptive responses have been well described because of their ecological and agricultural importance, our studies on the molecular mechanisms underlying these responses are still in their infancy. In the last decade, significant progresses have been made towards the identification of the molecular components which are involved in the control of plant responses to Pi starvation. In this article, we first provide an overview of some major responses of plants to Pi starvation, then summarize what we have known so far about the signaling components involved in these responses, as well as the roles of sugar and phytohormones.展开更多
The two-component signaling system has been studied in bacteria. It takes part in signal transduction of adaptive behavior. Recent studies have shown that a similar two-component system is also present in eukaryotes. ...The two-component signaling system has been studied in bacteria. It takes part in signal transduction of adaptive behavior. Recent studies have shown that a similar two-component system is also present in eukaryotes. Examples of this are ETR1 and CKI1 genes which may involve the signal transduction of plant hormone ethylene and cytokinin respectively. The cloning and characterization of a novel gene ( NTHK1 ) fragment from tobacco are presented.Its partial sequence codes for a product which shows similarity to many two-component signaling proteins. Southern blot analysis indicated that there are 2 to 3 copies of NTHK1 gene in tobacco genome (allotetraploid). Homologous genes may also exist in other plants such as Arabidopsis, soybean and spinach. The expression of NTHK1 gene has also been analyzed in tobacco.Further studies on the isolation of full-length cDNA of NTHK1 gene will elucidate more clearly its function in signal perception and transduction.展开更多
Cytokinin plays a critical role in plant growth and development by regulating cell divisions and cell differentiation. Recent studies suggest that cytokinin signaling is presumably mediated by a two-component system a...Cytokinin plays a critical role in plant growth and development by regulating cell divisions and cell differentiation. Recent studies suggest that cytokinin signaling is presumably mediated by a two-component system analogous to those found in bacteria and fungi, which transduces an external signal via a phosphorelay from the plasma membrane-anchored receptors to downstream effectors and regulators. Moreover, cytokinin signaling is highly interactive with other pathways, and many components of the pathway appear to be functionally redundant. Proper address of these questions will be crucial for our further understanding on this important network.展开更多
构建猪链球菌2型(Streptococcus suis type 2)强毒株05ZYH33二元信号转导系统2148hk/rr基因敲除突变体。构建中间为壮观霉素抗性基因,两侧为2148hk/rr编码基因上、下游同源序列的基因敲除质粒,通过同源重组筛选2148hk/rr编码基因敲除突...构建猪链球菌2型(Streptococcus suis type 2)强毒株05ZYH33二元信号转导系统2148hk/rr基因敲除突变体。构建中间为壮观霉素抗性基因,两侧为2148hk/rr编码基因上、下游同源序列的基因敲除质粒,通过同源重组筛选2148hk/rr编码基因敲除突变体。PCR分析和Southern杂交结果均显示2148hk/rr编码基因完全被壮观霉素抗性基因替代,基因敲除突变体构建成功。筛选获得05ZYH33二元信号转导系统2148hk/rr基因敲除突变体,为阐明该调控系统在猪链球菌致病过程中的作用奠定了基础。展开更多
基金supported by grants from the Natural Science Fund (ZR2010HM035) of Shandong Provincethe Shandong Provincial Health Development Project Fund (2011WSB19002) in China
文摘Oestrogen is essential for maintaining bone mass, and it has been demonstrated to induce osteoblast proliferation and bone formation.In this study, complementary DNA（cDNA） microarrays were used to identify and study the expression of novel genes that may be involved in MC3T3-E1 cells’ response to 17-b estradiol. MC3T3-E1 cells were inoculated in minimum essential media alpha（a-MEM）cell culture supplemented with 17-b estradiol at different concentrations and for different time periods. MC3T3-E1 cells treated with1028mol？L2117-b estradiol for 5 days exhibited the highest proliferation and alkaline phosphatase（ALP） activity; thus, this group was chosen for microarray analysis. The harvested RNA was used for microarray hybridisation and subsequent real-time reverse transcription polymerase chain reaction（RT-PCR） to validate the expression levels for selected genes. The microarray results were analysed using both functional and pathway analysis. In this study, microarray analysis detected 5 403 differentially expressed genes,of which 1 996 genes were upregulated and 3 407 genes were downregulated, 1 553 different functional classifications were identified by gene ontology（GO） analysis and 53 different pathways were involved based on pathway analysis. Among the differentially expressed genes, a portion not previously reported to be associated with the osteoblast response to oestrogen was identified. These findings clearly demonstrate that the expression of genes related to osteoblast proliferation, cell differentiation, collagens and transforming growth factor beta（TGF-b）-related cytokines increases, while the expression of genes related to apoptosis and osteoclast differentiation decreases, following the exposure of MC3T3-E1 cells to a-MEM supplemented with 17-b estradiol. Microarray analysis with functional gene classification is critical for a complete understanding of complementary intracellular processes. This microarray analysis provides large-scale gene expression data that require further confirmatory studies.
基金Supported by the National Natural Science Foundation of China (Nos. 40272054 and 40332022) and Research Grant of Doctoral Program for High Institue to Q. Wu
文摘Two-component systems are signal transduction systems which enable bacteria to regulate cellular functions in response to changing environmental conditions. The unicellular Synechocystis sp. PCC 6803 has become a model organism for a range of biochemical and molecular biology studies aiming at investigating environmental stress response. The publication of the complete genome sequence of the cyanobacterium Synechocystis sp. PCC 6803 provided a tremendous stimulus for research in this field, and at least 80 open reading frames were identified as members of the two-component signal transduction systems in this single species of cyanobacteria. To date, functional roles have been determined for only a limited number of such proteins. This review summarizes our current knowledge about the two-component signal transduction systems in Synechocystis sp. PCC 6803 and describes recent achievements in elucidating the functional roles of these systems.
文摘为了探索隐藏嗜酸菌(Acidiphilium cryptum)对多变极端矿山环境条件的感知和反应分子机制,预测和分析了隐藏嗜酸菌JF-5菌株的双组分信号转导系统(Two-component signal transduction system,TCS)的分布、结构及功能.鉴定了9对成对TCSs、2个杂合结构TCSs、3个孤儿组氨酸蛋白激酶(HK)和5个孤儿反应调节蛋白(RR);发现5个TCSs参与隐藏嗜酸菌对重金属响应转录调控;大多数HKs的N-末端具有接受信号的跨膜区、HAMP或PAS等结构域,RRs主要是OmpR亚家族,占总RRs的40%以上;从进化关系上来看,一些处在进化树同一分支上的共同聚簇TCS基因可能具有相同的进化途径.本研究结果可为研究隐藏嗜酸菌在极端环境中适应性分子机制提供新的方向.
文摘Phosphorus is one of the macronutrients essential for plant growth and development. Many soils around the world are deficient in phosphate （Pi） which is the form of phosphorus that plants can absorb and utilize. To cope with the stress of Pi starvation, plants have evolved many elaborate strategies to enhance the acquisition and utilization of Pi from the environment. These strategies include morphological, biochemical and physiological responses which ultimately enable plants to better survive under low Pi conditions. Though these adaptive responses have been well described because of their ecological and agricultural importance, our studies on the molecular mechanisms underlying these responses are still in their infancy. In the last decade, significant progresses have been made towards the identification of the molecular components which are involved in the control of plant responses to Pi starvation. In this article, we first provide an overview of some major responses of plants to Pi starvation, then summarize what we have known so far about the signaling components involved in these responses, as well as the roles of sugar and phytohormones.
文摘The two-component signaling system has been studied in bacteria. It takes part in signal transduction of adaptive behavior. Recent studies have shown that a similar two-component system is also present in eukaryotes. Examples of this are ETR1 and CKI1 genes which may involve the signal transduction of plant hormone ethylene and cytokinin respectively. The cloning and characterization of a novel gene ( NTHK1 ) fragment from tobacco are presented.Its partial sequence codes for a product which shows similarity to many two-component signaling proteins. Southern blot analysis indicated that there are 2 to 3 copies of NTHK1 gene in tobacco genome (allotetraploid). Homologous genes may also exist in other plants such as Arabidopsis, soybean and spinach. The expression of NTHK1 gene has also been analyzed in tobacco.Further studies on the isolation of full-length cDNA of NTHK1 gene will elucidate more clearly its function in signal perception and transduction.
基金supported by the"Century Program"of the Chinese Academy of Sciences,the National Natural Science Foundation of China(Grant Nos.30125025 and 30270142)the Ministry of Science and Technology of China to J.Z.(Grant No.2001AA225021)
文摘Cytokinin plays a critical role in plant growth and development by regulating cell divisions and cell differentiation. Recent studies suggest that cytokinin signaling is presumably mediated by a two-component system analogous to those found in bacteria and fungi, which transduces an external signal via a phosphorelay from the plasma membrane-anchored receptors to downstream effectors and regulators. Moreover, cytokinin signaling is highly interactive with other pathways, and many components of the pathway appear to be functionally redundant. Proper address of these questions will be crucial for our further understanding on this important network.
文摘构建猪链球菌2型(Streptococcus suis type 2)强毒株05ZYH33二元信号转导系统2148hk/rr基因敲除突变体。构建中间为壮观霉素抗性基因,两侧为2148hk/rr编码基因上、下游同源序列的基因敲除质粒,通过同源重组筛选2148hk/rr编码基因敲除突变体。PCR分析和Southern杂交结果均显示2148hk/rr编码基因完全被壮观霉素抗性基因替代,基因敲除突变体构建成功。筛选获得05ZYH33二元信号转导系统2148hk/rr基因敲除突变体,为阐明该调控系统在猪链球菌致病过程中的作用奠定了基础。
