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Peter D Nagy - One of the best experts on this subject based on the ideXlab platform.
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tombusvirus host interactions co opted evolutionarily conserved host factors take center court
Annual Review of Virology, 2016Co-Authors: Peter D NagyAbstract:Plant positive-strand (+)RNA viruses are intracellular infectious agents that reorganize subcellular membranes and rewire the cellular metabolism of host cells to achieve viral Replication in elaborate Replication compartments. This review describes the viral Replication Process based on tombusviruses, highlighting common strategies with other plant and animal viruses. Overall, the works on Tomato bushy stunt virus (TBSV) have revealed intriguing and complex functions of co-opted cellular translation factors, heat shock proteins, DEAD-box helicases, lipid transfer proteins, and membrane-deforming proteins in virus Replication. The emerging picture is that many of the co-opted host factors are from highly expressed and conserved protein families. By hijacking host proteins, phospholipids, sterols, and the actin network, TBSV exerts supremacy over the host cell to support viral Replication in large Replication compartments. Altogether, these advances in our understanding of tombusvirus-host interactions are...
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tombusvirus host interactions co opted evolutionarily conserved host factors take center court
Annual Review of Virology, 2016Co-Authors: Peter D NagyAbstract:Plant positive-strand (+)RNA viruses are intracellular infectious agents that reorganize subcellular membranes and rewire the cellular metabolism of host cells to achieve viral Replication in elaborate Replication compartments. This review describes the viral Replication Process based on tombusviruses, highlighting common strategies with other plant and animal viruses. Overall, the works on Tomato bushy stunt virus (TBSV) have revealed intriguing and complex functions of co-opted cellular translation factors, heat shock proteins, DEAD-box helicases, lipid transfer proteins, and membrane-deforming proteins in virus Replication. The emerging picture is that many of the co-opted host factors are from highly expressed and conserved protein families. By hijacking host proteins, phospholipids, sterols, and the actin network, TBSV exerts supremacy over the host cell to support viral Replication in large Replication compartments. Altogether, these advances in our understanding of tombusvirus-host interactions are...
Thomas Chittenden - One of the best experts on this subject based on the ideXlab platform.
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the transcription factor e2f interacts with the retinoblastoma product and a p107 cyclin a complex in a cell cycle regulated manner
Cell, 1992Co-Authors: Suman Shirodkar, David M Livingston, James A Decaprio, Jeffrey R Morgan, Thomas ChittendenAbstract:Abstract E2F is a transcription factor believed to play a role in the activation of genes required for cellular proliferation. Its regulation is likely important for maintenance of G0 and for the initiation of cell growth. The retinoblastoma product (RB) forms a complex with E2F in G1 in primary and established human cells. As these cells enter S, a second E2F-containing complex appears. It contains p107, a nuclear "pocket" protein with similarities in structure and protein-binding properties to RB, and cyclin A, a cyclin believed to play a role in facilitating DNA Replication. Hence, the regulation of E2F is carried out differently in G1 or S. The presence of cyclin A and a pocket protein, a possible cell growth regulator, in the same S phase-associated complex suggests a link between the function of E2F and the regulation of the DNA Replication Process.
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the transcription factor e2f interacts with the retinoblastoma product and a p107 cyclin a complex in a cell cycle regulated manner
Cell, 1992Co-Authors: Suman Shirodkar, David M Livingston, James A Decaprio, Jeffrey R Morgan, Thomas ChittendenAbstract:Abstract E2F is a transcription factor believed to play a role in the activation of genes required for cellular proliferation. Its regulation is likely important for maintenance of G0 and for the initiation of cell growth. The retinoblastoma product (RB) forms a complex with E2F in G1 in primary and established human cells. As these cells enter S, a second E2F-containing complex appears. It contains p107, a nuclear "pocket" protein with similarities in structure and protein-binding properties to RB, and cyclin A, a cyclin believed to play a role in facilitating DNA Replication. Hence, the regulation of E2F is carried out differently in G1 or S. The presence of cyclin A and a pocket protein, a possible cell growth regulator, in the same S phase-associated complex suggests a link between the function of E2F and the regulation of the DNA Replication Process.
Yoshizumi Ishino - One of the best experts on this subject based on the ideXlab platform.
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a heterodimeric dna polymerase evidence that members of euryarchaeota possess a distinct dna polymerase
Proceedings of the National Academy of Sciences of the United States of America, 1998Co-Authors: Isaac K. O. Cann, Kayoko Komori, Satoru Kanai, Yoshizumi IshinoAbstract:We describe here a DNA polymerase family highly conserved in Euryarchaeota, a subdomain of Archaea. The DNA polymerase is composed of two proteins, DP1 and DP2. Sequence analysis showed that considerable similarity exists between DP1 and the second subunit of eukaryotic DNA polymerase δ, a protein essential for the propagation of Eukarya, and that DP2 has conserved motifs found in proteins with nucleotide-polymerizing activity. These results, together with our previous biochemical analyses of one of the members, DNA polymerase II (DP1 + DP2) from Pyrococcus furiosus, implicate the DNA polymerases of this family in the DNA Replication Process of Euryarchaeota. The discovery of this DNA-polymerase family, aside from providing an opportunity to enhance our knowledge of the evolution of DNA polymerases, is a significant step toward the complete understanding of DNA Replication across the three domains of life.
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a heterodimeric dna polymerase evidence that members of euryarchaeota possess a distinct dna polymerase
Proceedings of the National Academy of Sciences of the United States of America, 1998Co-Authors: Isaac K. O. Cann, Kayoko Komori, Satoru Kanai, Yoshizumi IshinoAbstract:We describe here a DNA polymerase family highly conserved in Euryarchaeota, a subdomain of Archaea. The DNA polymerase is composed of two proteins, DP1 and DP2. Sequence analysis showed that considerable similarity exists between DP1 and the second subunit of eukaryotic DNA polymerase δ, a protein essential for the propagation of Eukarya, and that DP2 has conserved motifs found in proteins with nucleotide-polymerizing activity. These results, together with our previous biochemical analyses of one of the members, DNA polymerase II (DP1 + DP2) from Pyrococcus furiosus, implicate the DNA polymerases of this family in the DNA Replication Process of Euryarchaeota. The discovery of this DNA-polymerase family, aside from providing an opportunity to enhance our knowledge of the evolution of DNA polymerases, is a significant step toward the complete understanding of DNA Replication across the three domains of life.
Suman Shirodkar - One of the best experts on this subject based on the ideXlab platform.
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the transcription factor e2f interacts with the retinoblastoma product and a p107 cyclin a complex in a cell cycle regulated manner
Cell, 1992Co-Authors: Suman Shirodkar, David M Livingston, James A Decaprio, Jeffrey R Morgan, Thomas ChittendenAbstract:Abstract E2F is a transcription factor believed to play a role in the activation of genes required for cellular proliferation. Its regulation is likely important for maintenance of G0 and for the initiation of cell growth. The retinoblastoma product (RB) forms a complex with E2F in G1 in primary and established human cells. As these cells enter S, a second E2F-containing complex appears. It contains p107, a nuclear "pocket" protein with similarities in structure and protein-binding properties to RB, and cyclin A, a cyclin believed to play a role in facilitating DNA Replication. Hence, the regulation of E2F is carried out differently in G1 or S. The presence of cyclin A and a pocket protein, a possible cell growth regulator, in the same S phase-associated complex suggests a link between the function of E2F and the regulation of the DNA Replication Process.
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the transcription factor e2f interacts with the retinoblastoma product and a p107 cyclin a complex in a cell cycle regulated manner
Cell, 1992Co-Authors: Suman Shirodkar, David M Livingston, James A Decaprio, Jeffrey R Morgan, Thomas ChittendenAbstract:Abstract E2F is a transcription factor believed to play a role in the activation of genes required for cellular proliferation. Its regulation is likely important for maintenance of G0 and for the initiation of cell growth. The retinoblastoma product (RB) forms a complex with E2F in G1 in primary and established human cells. As these cells enter S, a second E2F-containing complex appears. It contains p107, a nuclear "pocket" protein with similarities in structure and protein-binding properties to RB, and cyclin A, a cyclin believed to play a role in facilitating DNA Replication. Hence, the regulation of E2F is carried out differently in G1 or S. The presence of cyclin A and a pocket protein, a possible cell growth regulator, in the same S phase-associated complex suggests a link between the function of E2F and the regulation of the DNA Replication Process.
Felix N Toka - One of the best experts on this subject based on the ideXlab platform.
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ectromelia virus suppresses expression of cathepsins and cystatins in conventional dendritic cells to efficiently execute the Replication Process
BMC Microbiology, 2019Co-Authors: Magdalena Bossowskanowicka, Malgorzata Gierynska, Karolina P Gregorczykzboroch, Matylda B Mielcarska, Justyna Struzik, Felix N Toka, Marta Romaniewicz, Monika M Kaczmarek, Marta GrodzikAbstract:Cathepsins are a group of endosomal proteases present in many cells including dendritic cells (DCs). The activity of cathepsins is regulated by their endogenous inhibitors – cystatins. Cathepsins are crucial to antigen Processing during viral and bacterial infections, and as such are a prerequisite to antigen presentation in the context of major histocompatibility complex class I and II molecules. Due to the involvement of DCs in both innate and adaptive immune responses, and the quest to understand the impact of poxvirus infection on host cells, we investigated the influence of ectromelia virus (ECTV) infection on cathepsin and cystatin levels in murine conventional DCs (cDCs). ECTV is a poxvirus that has evolved many mechanisms to avoid host immune response and is able to replicate productively in DCs. Our results showed that ECTV-infection of JAWS II DCs and primary murine GM-CSF-derived bone marrow cells down-regulated both mRNA and protein of cathepsin B, L and S, and cystatin B and C, particularly during the later stages of infection. Moreover, the activity of cathepsin B, L and S was confirmed to be diminished especially at later stages of infection in JAWS II cells. Consequently, ECTV-infected DCs had diminished ability to endocytose and Process a soluble antigen. Close examination of cellular protein distribution showed that beginning from early stages of infection, the remnants of cathepsin L and cystatin B co-localized and partially co-localized with viral Replication centers (viral factories), respectively. Moreover, viral yield increased in cDCs treated with siRNA against cathepsin B, L or S and subsequently infected with ECTV. Taken together, our results indicate that infection of cDCs with ECTV suppresses cathepsins and cystatins, and alters their cellular distribution which impairs the cDC function. We propose this as an additional viral strategy to escape immune responses, enabling the virus to replicate effectively in infected cells.
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Ectromelia virus suppresses expression of cathepsins and cystatins in conventional dendritic cells to efficiently execute the Replication Process
BMC, 2019Co-Authors: Magdalena Bossowska-nowicka, Malgorzata Gierynska, Matylda B Mielcarska, Justyna Struzik, Felix N Toka, Marta Romaniewicz, Monika M Kaczmarek, Marta Grodzik, Karolina P. Gregorczyk-zboroch, Lidia Szulc-dąbrowskaAbstract:Abstract Background Cathepsins are a group of endosomal proteases present in many cells including dendritic cells (DCs). The activity of cathepsins is regulated by their endogenous inhibitors – cystatins. Cathepsins are crucial to antigen Processing during viral and bacterial infections, and as such are a prerequisite to antigen presentation in the context of major histocompatibility complex class I and II molecules. Due to the involvement of DCs in both innate and adaptive immune responses, and the quest to understand the impact of poxvirus infection on host cells, we investigated the influence of ectromelia virus (ECTV) infection on cathepsin and cystatin levels in murine conventional DCs (cDCs). ECTV is a poxvirus that has evolved many mechanisms to avoid host immune response and is able to replicate productively in DCs. Results Our results showed that ECTV-infection of JAWS II DCs and primary murine GM-CSF-derived bone marrow cells down-regulated both mRNA and protein of cathepsin B, L and S, and cystatin B and C, particularly during the later stages of infection. Moreover, the activity of cathepsin B, L and S was confirmed to be diminished especially at later stages of infection in JAWS II cells. Consequently, ECTV-infected DCs had diminished ability to endocytose and Process a soluble antigen. Close examination of cellular protein distribution showed that beginning from early stages of infection, the remnants of cathepsin L and cystatin B co-localized and partially co-localized with viral Replication centers (viral factories), respectively. Moreover, viral yield increased in cDCs treated with siRNA against cathepsin B, L or S and subsequently infected with ECTV. Conclusions Taken together, our results indicate that infection of cDCs with ECTV suppresses cathepsins and cystatins, and alters their cellular distribution which impairs the cDC function. We propose this as an additional viral strategy to escape immune responses, enabling the virus to replicate effectively in infected cells
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Additional file 2: of Ectromelia virus suppresses expression of cathepsins and cystatins in conventional dendritic cells to efficiently execute the Replication Process
2019Co-Authors: Magdalena Bossowska-nowicka, Malgorzata Gierynska, Matylda B Mielcarska, Justyna Struzik, Felix N Toka, Marta Romaniewicz, Marta Grodzik, Karolina P. Gregorczyk-zboroch, Monika Kaczmarek, Lidia Szulc-dąbrowskaAbstract:Figure S2 Confirmation of gene knockdown of cathepsin B, L or S, and cystatin B or C in JAWS II (A) and GM-BM (B) cells. The level of each protein was normalized to GAPDH. Western blots of control non treated cells, control siRNA-A treated cells and cells treated against CtsB, CtsL, CtsS, CstB and Cst3 at 48 and 72 h of siRNA treatment in JAWS II and GM-BM cells. (TIF 2400 kb
