Dynamic protein-protein interactions are essential for proper cell functioning.Homointeraction events—physical interactions between the same type of proteins—represent a pivotal subset of protein-protein interaction...Dynamic protein-protein interactions are essential for proper cell functioning.Homointeraction events—physical interactions between the same type of proteins—represent a pivotal subset of protein-protein interactions that are widely exploited in activating intracellular signaling pathways.Capacities of modulating protein-protein interactions with spatial and temporal resolution are greatly desired to decipher the dynamic nature of signal transduction mechanisms.The emerging optogenetic technology,based on genetically encoded light-sensitive proteins,provides promising opportunities to dissect the highly complex signaling networks with unmatched specificity and spatiotemporal precision.Here we review recent achievements in the development of optogenetic tools enabling light-inducible protein-protein homo-interactions and their applications in optical activation of signaling pathways.展开更多
Object: The authors studied the influence of CO2 pneumoperitoneum on intracellular pH and signal transduction arising from cancer cell multiplication in laparoscopic tumor operation. Method: They set up a simulation o...Object: The authors studied the influence of CO2 pneumoperitoneum on intracellular pH and signal transduction arising from cancer cell multiplication in laparoscopic tumor operation. Method: They set up a simulation of pneumoperitoneum under different CO2 pressure, and then measured the variation of intracellular pH (pHi) at different time and the activity of protein kinase C (PKC) and protein phosphatase 2a (PP2a) at the end of the pneumoperitoneum. After 1 week, the concentration of cancer cells in the culture medium was calculated. Result: When the pressure of CO2 pneumoperitoneum was 0, 10, 20, 30 mmHg respectively, the average pHi was 7.273, 7.075, 6.783, 6.693 at the end of the pneumoperitoneum; PKC activity was 159.4, 168.5,178.0, 181.6 nmol/(g.min) and PP2a was 4158.3, 4066.9, 3984.0, 3878.5 nmol/(g.min) respectively. After 1 week, the cancer cells concentration was 2.15×105, 2.03×105, 2.20×105, 2.18×105 L-1. Conclusion: CO2 pneumoperitoneum could promote acidosis in cancer cells, inducing the activation of protein kinase C and deactivation of protein phosphatase 2a, but it could not accelerate the mitosis rate of the cancer cells.展开更多
For genome multiplication hepadnaviruses use the tran-scriptional machinery of the cell that is found within the nucleus.Thus the viral genome has to be transported through the cytoplasm and nuclear pore.The intracy-t...For genome multiplication hepadnaviruses use the tran-scriptional machinery of the cell that is found within the nucleus.Thus the viral genome has to be transported through the cytoplasm and nuclear pore.The intracy-tosolic translocation is facilitated by the viral capsid that surrounds the genome and that interacts with cellular microtubules.The subsequent passage through the nu-clear pore complexes(NPC) is mediated by the nuclear transport receptors importin α and β.Importin α binds to the C-terminus of the capsid protein that comprises a nuclear localization signal(NLS).The exposure of the NLS is regulated and depends upon genome maturation and/or phosphorylation of the capsid protein.As for oth-er karyophilic cargos using this pathway importin α inter-acts with importin β that facilitates docking of the import complex to the NPC and the passage through the pore.Being a unique strategy,the import of the viral capsid is incomplete in that it becomes arrested inside the nuclear basket,which is a cage-like structure on the karyoplas-mic face of the NPC.Presumably only this compartment provides the factors that are required for capsid disas-sembly and genome release that is restricted to those capsids comprising a mature viral DNA genome.展开更多
A monolayer of endothelial cells (ECs) lines the lumen of blood vessels and forms a multifunctional transducing organ that mediates a plethora of cardiovascular processes. The activation of ECs from as state of quiesc...A monolayer of endothelial cells (ECs) lines the lumen of blood vessels and forms a multifunctional transducing organ that mediates a plethora of cardiovascular processes. The activation of ECs from as state of quiescence is, therefore, regarded among the early events leading to the onset and progression of potentially lethal diseases, such as hypertension, myocardial infarction, brain stroke, and tumor. Intracellular Ca2+ signals have long been know to play a central role in the complex network of signaling pathways regulating the endothelial functions. Notably, recent work has outlined how any change in the pattern of expression of endothelial channels, transporters and pumps involved in the modulation of intracellular Ca2+ levels may dramatically affect whole body homeostasis. Vascular ECs may react to both mechanical and chemical stimuli by generating a variety of intracellular Ca2+ signals, ranging from brief, localized Ca2+ pulses to prolonged Ca2+ oscillations engulfing the whole cytoplasm. The well-defined spatiotemporal profile of the subcellular Ca2+ signals elicited in ECs by specific extracellular inputs depends on the interaction between Ca2+ releasing channels, which arelocated both on the plasma membrane and in a number of intracellular organelles, and Ca2+ removing systems. The present article aims to summarize both the past and recent literature in the field to provide a clear-cut picture of our current knowledge on the molecular nature and the role played by the components of the Ca2+ machinery in vascular ECs under both physiological and pathological conditions.展开更多
AIM:To investigate the mechanisms of chloride intracellular channel 1(CLIC1)in the metastasis of colon cancer under hypoxia-reoxygenation(H-R)conditions.METHODS:Fluorescent probes were used to detect reactive oxygen s...AIM:To investigate the mechanisms of chloride intracellular channel 1(CLIC1)in the metastasis of colon cancer under hypoxia-reoxygenation(H-R)conditions.METHODS:Fluorescent probes were used to detect reactive oxygen species(ROS)in LOVO cells.Wound healing assay and transwell assay were performed to examine the migration and invasion of LOVO cells.Expression of CLIC1 mRNA and protein,p-ERK,MMP-2and MMP-9 proteins was analyzed by reverse transcription-polymerase chain reaction and Western blot.METHODS:H-R treatment increased the intracellular ROS level in LOVO cells.The mRNA and protein expression of CLIC1 was elevated under H-R conditions.Functional inhibition of CLIC1 markedly decreased the H-R-enhanced ROS generation,cell migration,invasion and phosphorylation of ERK in treated LOVO cells.Additionally,the expression of MMP-2 and MMP-9 could be regulated by CLIC1-mediated ROS/ERK pathway.CONCLUSION:Our results suggest that CLIC1 protein is involved in the metastasis of colon cancer LOVO cells via regulating the ROS/ERK pathway in the H-R process.展开更多
The pathological implication of amyloid precursor protein(APP)in Alzheimer’s disease has been widely documented due to its involvement in the generation of amyloid-β peptide.However,the physiological functions of AP...The pathological implication of amyloid precursor protein(APP)in Alzheimer’s disease has been widely documented due to its involvement in the generation of amyloid-β peptide.However,the physiological functions of APP are still poorly understood.APP is considered a multimodal protein due to its role in a wide variety of processes,both in the embryo and in the adult brain.Specifically,APP seems to play a key role in the proliferation,differentiation and maturation of neural stem cells.In addition,APP can be processed through two canonical processing pathways,generating different functionally active fragments:soluble APP-α,soluble APP-β,amyloid-β peptide and the APP intracellular C-terminal domain.These fragments also appear to modulate various functions in neural stem cells,including the processes of proliferation,neurogenesis,gliogenesis or cell death.However,the molecular mechanisms involved in these effects are still unclear.In this review,we summarize the physiological functions of APP and its main proteolytic derivatives in neural stem cells,as well as the possible signaling pathways that could be implicated in these effects.The knowledge of these functions and signaling pathways involved in the onset or during the development of Alzheimer’s disease is essential to advance the understanding of the pathogenesis of Alzheimer’s disease,and in the search for potential therapeutic targets.展开更多
基金supported by a Shun Hing Institute of Advanced Engineering Grant(No.4720247)a General Research Fund/Early Career Scheme(No.24201919)from the Research Grants Council of Hong Kong Special Administrative Region(to LD)。
文摘Dynamic protein-protein interactions are essential for proper cell functioning.Homointeraction events—physical interactions between the same type of proteins—represent a pivotal subset of protein-protein interactions that are widely exploited in activating intracellular signaling pathways.Capacities of modulating protein-protein interactions with spatial and temporal resolution are greatly desired to decipher the dynamic nature of signal transduction mechanisms.The emerging optogenetic technology,based on genetically encoded light-sensitive proteins,provides promising opportunities to dissect the highly complex signaling networks with unmatched specificity and spatiotemporal precision.Here we review recent achievements in the development of optogenetic tools enabling light-inducible protein-protein homo-interactions and their applications in optical activation of signaling pathways.
基金Project supported by Research and Development Funds of Second Affiliated Hospital, School of Medicine, Zhejiang University, China
文摘Object: The authors studied the influence of CO2 pneumoperitoneum on intracellular pH and signal transduction arising from cancer cell multiplication in laparoscopic tumor operation. Method: They set up a simulation of pneumoperitoneum under different CO2 pressure, and then measured the variation of intracellular pH (pHi) at different time and the activity of protein kinase C (PKC) and protein phosphatase 2a (PP2a) at the end of the pneumoperitoneum. After 1 week, the concentration of cancer cells in the culture medium was calculated. Result: When the pressure of CO2 pneumoperitoneum was 0, 10, 20, 30 mmHg respectively, the average pHi was 7.273, 7.075, 6.783, 6.693 at the end of the pneumoperitoneum; PKC activity was 159.4, 168.5,178.0, 181.6 nmol/(g.min) and PP2a was 4158.3, 4066.9, 3984.0, 3878.5 nmol/(g.min) respectively. After 1 week, the cancer cells concentration was 2.15×105, 2.03×105, 2.20×105, 2.18×105 L-1. Conclusion: CO2 pneumoperitoneum could promote acidosis in cancer cells, inducing the activation of protein kinase C and deactivation of protein phosphatase 2a, but it could not accelerate the mitosis rate of the cancer cells.
文摘For genome multiplication hepadnaviruses use the tran-scriptional machinery of the cell that is found within the nucleus.Thus the viral genome has to be transported through the cytoplasm and nuclear pore.The intracy-tosolic translocation is facilitated by the viral capsid that surrounds the genome and that interacts with cellular microtubules.The subsequent passage through the nu-clear pore complexes(NPC) is mediated by the nuclear transport receptors importin α and β.Importin α binds to the C-terminus of the capsid protein that comprises a nuclear localization signal(NLS).The exposure of the NLS is regulated and depends upon genome maturation and/or phosphorylation of the capsid protein.As for oth-er karyophilic cargos using this pathway importin α inter-acts with importin β that facilitates docking of the import complex to the NPC and the passage through the pore.Being a unique strategy,the import of the viral capsid is incomplete in that it becomes arrested inside the nuclear basket,which is a cage-like structure on the karyoplas-mic face of the NPC.Presumably only this compartment provides the factors that are required for capsid disas-sembly and genome release that is restricted to those capsids comprising a mature viral DNA genome.
文摘A monolayer of endothelial cells (ECs) lines the lumen of blood vessels and forms a multifunctional transducing organ that mediates a plethora of cardiovascular processes. The activation of ECs from as state of quiescence is, therefore, regarded among the early events leading to the onset and progression of potentially lethal diseases, such as hypertension, myocardial infarction, brain stroke, and tumor. Intracellular Ca2+ signals have long been know to play a central role in the complex network of signaling pathways regulating the endothelial functions. Notably, recent work has outlined how any change in the pattern of expression of endothelial channels, transporters and pumps involved in the modulation of intracellular Ca2+ levels may dramatically affect whole body homeostasis. Vascular ECs may react to both mechanical and chemical stimuli by generating a variety of intracellular Ca2+ signals, ranging from brief, localized Ca2+ pulses to prolonged Ca2+ oscillations engulfing the whole cytoplasm. The well-defined spatiotemporal profile of the subcellular Ca2+ signals elicited in ECs by specific extracellular inputs depends on the interaction between Ca2+ releasing channels, which arelocated both on the plasma membrane and in a number of intracellular organelles, and Ca2+ removing systems. The present article aims to summarize both the past and recent literature in the field to provide a clear-cut picture of our current knowledge on the molecular nature and the role played by the components of the Ca2+ machinery in vascular ECs under both physiological and pathological conditions.
基金Supported by The "Eleventh Five-year Plan" for Medical Sci-ence Development of PLA,No.06MB243the National Natural Science Foundation of China,No.81101101 and No.51273165+1 种基金the Key Project of Chinese Ministry of Education,No.212149the Projects of Sichuan Province,No.2010SZ0294,No.2011JQ0032 and No.12ZB038
文摘AIM:To investigate the mechanisms of chloride intracellular channel 1(CLIC1)in the metastasis of colon cancer under hypoxia-reoxygenation(H-R)conditions.METHODS:Fluorescent probes were used to detect reactive oxygen species(ROS)in LOVO cells.Wound healing assay and transwell assay were performed to examine the migration and invasion of LOVO cells.Expression of CLIC1 mRNA and protein,p-ERK,MMP-2and MMP-9 proteins was analyzed by reverse transcription-polymerase chain reaction and Western blot.METHODS:H-R treatment increased the intracellular ROS level in LOVO cells.The mRNA and protein expression of CLIC1 was elevated under H-R conditions.Functional inhibition of CLIC1 markedly decreased the H-R-enhanced ROS generation,cell migration,invasion and phosphorylation of ERK in treated LOVO cells.Additionally,the expression of MMP-2 and MMP-9 could be regulated by CLIC1-mediated ROS/ERK pathway.CONCLUSION:Our results suggest that CLIC1 protein is involved in the metastasis of colon cancer LOVO cells via regulating the ROS/ERK pathway in the H-R process.
基金supported by grants from the Ministerio de Ciencia e Innovación-Instituto de Salud Carlos Ⅲ(PI-10/00291 and MPY1412/09)Ministerio de Economía y Competitividad(SAF2015-71140-R)+2 种基金Comunidad de Madrid(Neurostem-Comunidad de Madrid consortium S2010/BMD-2336)supported by grants from Plan de Empleo Juvenil-Ministerio de Economía y Competitividad
文摘The pathological implication of amyloid precursor protein(APP)in Alzheimer’s disease has been widely documented due to its involvement in the generation of amyloid-β peptide.However,the physiological functions of APP are still poorly understood.APP is considered a multimodal protein due to its role in a wide variety of processes,both in the embryo and in the adult brain.Specifically,APP seems to play a key role in the proliferation,differentiation and maturation of neural stem cells.In addition,APP can be processed through two canonical processing pathways,generating different functionally active fragments:soluble APP-α,soluble APP-β,amyloid-β peptide and the APP intracellular C-terminal domain.These fragments also appear to modulate various functions in neural stem cells,including the processes of proliferation,neurogenesis,gliogenesis or cell death.However,the molecular mechanisms involved in these effects are still unclear.In this review,we summarize the physiological functions of APP and its main proteolytic derivatives in neural stem cells,as well as the possible signaling pathways that could be implicated in these effects.The knowledge of these functions and signaling pathways involved in the onset or during the development of Alzheimer’s disease is essential to advance the understanding of the pathogenesis of Alzheimer’s disease,and in the search for potential therapeutic targets.
