RNA granules are cytoplasmic, microscopically visible, non-membrane ribo-nucleoprotein structures and are important posttranscriptional regulators in gene expression by controlling RNA translation and stability. TIA/G...RNA granules are cytoplasmic, microscopically visible, non-membrane ribo-nucleoprotein structures and are important posttranscriptional regulators in gene expression by controlling RNA translation and stability. TIA/G3BP/PABP-specific stress granules(SG) and GW182/DCP-specific RNA processing bodies(PB) are two major distinguishable RNA granules in somatic cells and contain various ribosomal subunits, translation factors, scaffold proteins, RNA-binding proteins, RNA decay enzymes and helicases to exclude m RNAs from the cellular active translational pool. Although SG formation is inducible due to cellular stress, PB exist physiologically in every cell. Both RNA granules are important components of the host antiviral defense. Virus infection imposes stress on host cells and thus induces SG formation. However, both RNA and DNA viruses must confront the hostile environment of host innate immunity and apply various strategies to block the formation of SG and PB for their effective infection and multiplication. This review summarizes the current research development in the field and the mechanisms of how individual viruses suppress the formation of host SG and PB for virus production.展开更多
The human CCR4-NOT deadenylase complex consists of at least nine enzymatic and non-enzymatic subunits.Accumulating evidence suggests that the non-enzymatic subunits are involved in the regulation of mRNA deadenylation...The human CCR4-NOT deadenylase complex consists of at least nine enzymatic and non-enzymatic subunits.Accumulating evidence suggests that the non-enzymatic subunits are involved in the regulation of mRNA deadenylation,although their precise roles remain to be established.In this study,we addressed the function of the CNOT1 subunit by depleting its expression in HeLa cells.Flow cytometric analysis revealed that the sub G1 fraction was increased in CNOT1-depleted cells.Virtually,the same level of the sub G1 fraction was seen when cells were treated with a mixture of siRNAs targeted against all enzymatic subunits,suggesting that CNOT1 depletion induces apoptosis by destroying the CCR4-NOT-associated deadenylase activity.Further analysis revealed that CNOT1 depletion leads to a reduction in the amount of other CCR4-NOT subunits.Importantly,the specific activity of the CNOT6L immunoprecipitates-associated deadenylase from CNOT1-depleted cells was less than that from control cells.The formation of P-bodies,where mRNA decay is reported to take place,was largely suppressed in CNOT1-depleted cells.Therefore,CNOT1 has an important role in exhibiting enzymatic activity of the CCR4-NOT complex,and thus is critical in control of mRNA deadenylation and mRNA decay.We further showed that CNOT1 depletion enhanced CHOP mRNA levels and activated caspase-4,which is associated with endoplasmic reticulum ER stress-induced apoptosis.Taken together,CNOT1 depletion structurally and functionally deteriorates the CCR4-NOTcomplex and induces stabilization of mRNAs,which results in the increment of translation causing ER stress-mediated apoptosis.We conclude that CNOT1 contributes to cell viability by securing the activity of the CCR4-NOT deadenylase.展开更多
It is shown that a convex body has minimal dual p-surface area among its affine transformations of the same volume if and only if its dual p-surface area measure is isotropic. A double-sided estimate for the （n-1）-d...It is shown that a convex body has minimal dual p-surface area among its affine transformations of the same volume if and only if its dual p-surface area measure is isotropic. A double-sided estimate for the （n-1）-dimensional volume of the intersection of a dual p-surface isotropic convex body in terms of its affine invariant dual p-surface quantity is given. Furthermore, the dual p-isopermetric inequality is obtained.展开更多
The casepase is considered to regulate the process of programmed cell death in the development of organisms. In this study, caspase 3-like protease was detected by immunohistochemistry and immunoelectron microscopy du...The casepase is considered to regulate the process of programmed cell death in the development of organisms. In this study, caspase 3-like protease was detected by immunohistochemistry and immunoelectron microscopy during the development of sieve element and tracheary element of stem in Cucurbita moschata Duch. Antibody with brown color （under light microscopy） and gold particles （under transmission electron microscopy） for detecting caspase 3-like protease was mainly displayed in inner phloem, external phloem and xylem in the region close to procambium. From the results it was considered that caspase 3-like protease did exist in vascular elements and played different roles during the development of sieve and tracheary elements, and different types of programmed cell death might be carried out. The caspase 3-like protease mainly participated in making cytoplasmic streaming cease and in degrading P-protein bodies; however, it rarely participated in the function for signal transferring in the developmental sieve element. However, it might induce calcium accumulation for rupturing the tonoplast in the signal of PCD in the developmental tracheary element.展开更多
基金supported by grants from the China Natural Science Foundation (81825015 and 31630086)the Natural Science Foundation of Hubei Province Innovation Group (2017CFA022)Intramural Research Program of NCI/NIH (1ZIASC010357 to ZMZ)
文摘RNA granules are cytoplasmic, microscopically visible, non-membrane ribo-nucleoprotein structures and are important posttranscriptional regulators in gene expression by controlling RNA translation and stability. TIA/G3BP/PABP-specific stress granules(SG) and GW182/DCP-specific RNA processing bodies(PB) are two major distinguishable RNA granules in somatic cells and contain various ribosomal subunits, translation factors, scaffold proteins, RNA-binding proteins, RNA decay enzymes and helicases to exclude m RNAs from the cellular active translational pool. Although SG formation is inducible due to cellular stress, PB exist physiologically in every cell. Both RNA granules are important components of the host antiviral defense. Virus infection imposes stress on host cells and thus induces SG formation. However, both RNA and DNA viruses must confront the hostile environment of host innate immunity and apply various strategies to block the formation of SG and PB for their effective infection and multiplication. This review summarizes the current research development in the field and the mechanisms of how individual viruses suppress the formation of host SG and PB for virus production.
基金supported by grants-in-aid from the Japan Society for the Promotion of Science and from the Ministry of Education,Culture,Sports,Science and Technology,Japan.
文摘The human CCR4-NOT deadenylase complex consists of at least nine enzymatic and non-enzymatic subunits.Accumulating evidence suggests that the non-enzymatic subunits are involved in the regulation of mRNA deadenylation,although their precise roles remain to be established.In this study,we addressed the function of the CNOT1 subunit by depleting its expression in HeLa cells.Flow cytometric analysis revealed that the sub G1 fraction was increased in CNOT1-depleted cells.Virtually,the same level of the sub G1 fraction was seen when cells were treated with a mixture of siRNAs targeted against all enzymatic subunits,suggesting that CNOT1 depletion induces apoptosis by destroying the CCR4-NOT-associated deadenylase activity.Further analysis revealed that CNOT1 depletion leads to a reduction in the amount of other CCR4-NOT subunits.Importantly,the specific activity of the CNOT6L immunoprecipitates-associated deadenylase from CNOT1-depleted cells was less than that from control cells.The formation of P-bodies,where mRNA decay is reported to take place,was largely suppressed in CNOT1-depleted cells.Therefore,CNOT1 has an important role in exhibiting enzymatic activity of the CCR4-NOT complex,and thus is critical in control of mRNA deadenylation and mRNA decay.We further showed that CNOT1 depletion enhanced CHOP mRNA levels and activated caspase-4,which is associated with endoplasmic reticulum ER stress-induced apoptosis.Taken together,CNOT1 depletion structurally and functionally deteriorates the CCR4-NOTcomplex and induces stabilization of mRNAs,which results in the increment of translation causing ER stress-mediated apoptosis.We conclude that CNOT1 contributes to cell viability by securing the activity of the CCR4-NOT deadenylase.
基金Project supported by the National Natural Science Foundation of China (Grant No.10671117)
文摘It is shown that a convex body has minimal dual p-surface area among its affine transformations of the same volume if and only if its dual p-surface area measure is isotropic. A double-sided estimate for the （n-1）-dimensional volume of the intersection of a dual p-surface isotropic convex body in terms of its affine invariant dual p-surface quantity is given. Furthermore, the dual p-isopermetric inequality is obtained.
基金Supported by the National Natural Science Foundation of China (30470863).
文摘The casepase is considered to regulate the process of programmed cell death in the development of organisms. In this study, caspase 3-like protease was detected by immunohistochemistry and immunoelectron microscopy during the development of sieve element and tracheary element of stem in Cucurbita moschata Duch. Antibody with brown color （under light microscopy） and gold particles （under transmission electron microscopy） for detecting caspase 3-like protease was mainly displayed in inner phloem, external phloem and xylem in the region close to procambium. From the results it was considered that caspase 3-like protease did exist in vascular elements and played different roles during the development of sieve and tracheary elements, and different types of programmed cell death might be carried out. The caspase 3-like protease mainly participated in making cytoplasmic streaming cease and in degrading P-protein bodies; however, it rarely participated in the function for signal transferring in the developmental sieve element. However, it might induce calcium accumulation for rupturing the tonoplast in the signal of PCD in the developmental tracheary element.
