细胞表面的外来刺激可引起一系列胞内信号，对促进细胞增值、分化和凋亡起重要的生理作用。而信号转导途径中的某个环节异常，可引起细胞异常增殖和细胞外基质过多集聚，这是肠道炎症和肿瘤的病理基础。促分裂原蛋白活化激酶（mitogen—...细胞表面的外来刺激可引起一系列胞内信号，对促进细胞增值、分化和凋亡起重要的生理作用。而信号转导途径中的某个环节异常，可引起细胞异常增殖和细胞外基质过多集聚，这是肠道炎症和肿瘤的病理基础。促分裂原蛋白活化激酶（mitogen—activated protein kinases，MAPKs）是连接细胞膜表面受体和基因表达的重要信号调节酶，已发现哺乳动物肠道组织细胞内至少存在4种MAPKs，即ERK／MAPK（或称p44／42MAPK）、c-Jun氨基末端激酶（JNK1／JNK2），p38MAPK（α，β）和ERK5／BMK。展开更多
目的:目的研究167例乙肝病毒截短型表面抗原中蛋白(C-terminally truncated middle size surface proteins,MHBst167)和X蛋白(hepatitis B virus X protein,HBx)对肾小管上皮细胞核转录因子κB(nuclear factor-kappaB,NF-κB)活化的影...目的:目的研究167例乙肝病毒截短型表面抗原中蛋白(C-terminally truncated middle size surface proteins,MHBst167)和X蛋白(hepatitis B virus X protein,HBx)对肾小管上皮细胞核转录因子κB(nuclear factor-kappaB,NF-κB)活化的影响及其相关机制探讨。方法:肾小管上皮细胞系(HK-2)转染mhbst167或(和)hbx后,蛋白印迹法检测NF-κB核易位及其抑制蛋白(inhibitor of nuclear factor-kappa B,IκBα)磷酸化水平的变化,凝胶电泳迁移率和双萤光素酶报告基因分析进一步检测NF-κB活性;通过对蛋白激酶C(protein kinase C,PKC)活性和细胞外调节激酶(extracellular regulated protein kinases,ERK)磷酸化水平检测探讨NF-κB活化的机制。结果:HK-2细胞转染mhbst167或(和)hbx基因后,NF-κB核易位、磷酸化IκBα、κB结合活性及κB基因转录均增加(P<0.05);且PKC激酶活性和磷酸化ERK水平也增加(P<0.05),而Raf蛋白均无表达。结论:在肾小管上皮细胞中,MHBst167/HBx可能通过PKC/ERK通路(非Raf依赖性)活化NF-κB。展开更多
Proteins like Raf kinase inhibitory protein (RKIP) that serve as modulators of signaling pathways, either by promoting or inhibiting the formation of productive signaling complexes through protein-protein interactions...Proteins like Raf kinase inhibitory protein (RKIP) that serve as modulators of signaling pathways, either by promoting or inhibiting the formation of productive signaling complexes through protein-protein interactions, have been demon- strated to play an increasingly important role in a number of cell types and organisms. These proteins have been implicated in development as well as the progression of cancer. RKIP is a particularly interesting regulator, as it is a highly conserved, ubiquitously expressed protein that has been shown to play a role in growth and differentiation in a number of organisms and can regulate multiple signaling pathways. RKIP is also the first MAP kinase signaling modulator to be identified as playing a role in cancer metastasis, and identification of the mechanism by which it regulates Raf-1 activation provides new targets for therapeutic intervention.展开更多
Cells have a multitude of controls to maintain their integrity and prevent random switching from one biological state to another. Raf Kinase Inhibitory Protein （RKIP）, a member of the phosphatidylethanolamine bindin...Cells have a multitude of controls to maintain their integrity and prevent random switching from one biological state to another. Raf Kinase Inhibitory Protein （RKIP）, a member of the phosphatidylethanolamine binding protein （PEBP） family, is representative of a new class of modulators of signaling cascades that function to maintain the “yin yang” or balance of biological systems. RKIP inhibits MAP kinase （Raf-MEK-ERK）, G protein-coupled receptor （GPCR） kinase and NFkB signaling cascades. Because RKIP targets different kinases dependent upon its state ofphosphorylation, RKIP also acts to integrate crosstalk initiated by multiple environmental stimuli. Loss or depletion of RKIP results in disruption of the normal cellular stasis and can lead to chromosomal abnormalities and disease states such as cancer. Since RKIP and the PEBP family have been reviewed previously, the goal of this analysis is to provide an update and highlight some of the unique features of RKIP that make it a critical player in the regulation of cellular signaling processes.展开更多
文摘细胞表面的外来刺激可引起一系列胞内信号，对促进细胞增值、分化和凋亡起重要的生理作用。而信号转导途径中的某个环节异常，可引起细胞异常增殖和细胞外基质过多集聚，这是肠道炎症和肿瘤的病理基础。促分裂原蛋白活化激酶（mitogen—activated protein kinases，MAPKs）是连接细胞膜表面受体和基因表达的重要信号调节酶，已发现哺乳动物肠道组织细胞内至少存在4种MAPKs，即ERK／MAPK（或称p44／42MAPK）、c-Jun氨基末端激酶（JNK1／JNK2），p38MAPK（α，β）和ERK5／BMK。
文摘目的:目的研究167例乙肝病毒截短型表面抗原中蛋白(C-terminally truncated middle size surface proteins,MHBst167)和X蛋白(hepatitis B virus X protein,HBx)对肾小管上皮细胞核转录因子κB(nuclear factor-kappaB,NF-κB)活化的影响及其相关机制探讨。方法:肾小管上皮细胞系(HK-2)转染mhbst167或(和)hbx后,蛋白印迹法检测NF-κB核易位及其抑制蛋白(inhibitor of nuclear factor-kappa B,IκBα)磷酸化水平的变化,凝胶电泳迁移率和双萤光素酶报告基因分析进一步检测NF-κB活性;通过对蛋白激酶C(protein kinase C,PKC)活性和细胞外调节激酶(extracellular regulated protein kinases,ERK)磷酸化水平检测探讨NF-κB活化的机制。结果:HK-2细胞转染mhbst167或(和)hbx基因后,NF-κB核易位、磷酸化IκBα、κB结合活性及κB基因转录均增加(P<0.05);且PKC激酶活性和磷酸化ERK水平也增加(P<0.05),而Raf蛋白均无表达。结论:在肾小管上皮细胞中,MHBst167/HBx可能通过PKC/ERK通路(非Raf依赖性)活化NF-κB。
文摘Proteins like Raf kinase inhibitory protein (RKIP) that serve as modulators of signaling pathways, either by promoting or inhibiting the formation of productive signaling complexes through protein-protein interactions, have been demon- strated to play an increasingly important role in a number of cell types and organisms. These proteins have been implicated in development as well as the progression of cancer. RKIP is a particularly interesting regulator, as it is a highly conserved, ubiquitously expressed protein that has been shown to play a role in growth and differentiation in a number of organisms and can regulate multiple signaling pathways. RKIP is also the first MAP kinase signaling modulator to be identified as playing a role in cancer metastasis, and identification of the mechanism by which it regulates Raf-1 activation provides new targets for therapeutic intervention.
文摘Cells have a multitude of controls to maintain their integrity and prevent random switching from one biological state to another. Raf Kinase Inhibitory Protein （RKIP）, a member of the phosphatidylethanolamine binding protein （PEBP） family, is representative of a new class of modulators of signaling cascades that function to maintain the “yin yang” or balance of biological systems. RKIP inhibits MAP kinase （Raf-MEK-ERK）, G protein-coupled receptor （GPCR） kinase and NFkB signaling cascades. Because RKIP targets different kinases dependent upon its state ofphosphorylation, RKIP also acts to integrate crosstalk initiated by multiple environmental stimuli. Loss or depletion of RKIP results in disruption of the normal cellular stasis and can lead to chromosomal abnormalities and disease states such as cancer. Since RKIP and the PEBP family have been reviewed previously, the goal of this analysis is to provide an update and highlight some of the unique features of RKIP that make it a critical player in the regulation of cellular signaling processes.
