The Experts below are selected from a list of 335625 Experts worldwide ranked by ideXlab platform
Miriam Gochin - One of the best experts on this subject based on the ideXlab platform.
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biochemistry and biophysics of hiv 1 gp41 membrane interactions and implications for hiv 1 envelope protein mediated Viral Cell fusion and fusion inhibitor design
2011Co-Authors: Miriam GochinAbstract:Human immunodeficiency virus type 1 (HIV-1), the pathogen of acquired immunodeficiency syndrome (AIDS), causes ∼2 millions death every year and still defies an effective vaccine. HIV-1 infects host Cells through envelope protein - mediated virus-Cell fusion. The transmembrane subunit of envelope protein, gp41, is the molecular machinery which facilitates fusion. Its ectodomain contains several distinguishing functional domains, fusion peptide (FP), Nterminal heptad repeat (NHR), C-terminal heptad repeat (CHR) and membrane proximal extraCellular region (MPER). During the fusion process, FP inserts into the host Cell membrane, and an extended gp41 prehairpin conformation bridges the Viral and Cell membranes through MPER and FP respectively. Subsequent conformational change of the unstable prehairpin results in a coiled-coil 6-helix bundle (6HB) structure formed between NHR and CHR. The energetics of 6HB formation drives membrane apposition and fusion. Drugs targeting gp41 functional domains to prevent 6HB formation inhibit HIV-1 infection. T20 (enfuvirtide, Fuzeon) was approved by the US FDA in 2003 as the first fusion inhibitor. It is a 36-residue peptide from the gp41 CHR, and it inhibits 6HB formation by targeting NHR and lipids. Development of new fusion inhibitors, especially small molecule drugs, is encouraged to overcome the shortcomings of T20 as a peptide drug. Hydrophobic characteristics and membrane association are critical for gp41 function and mechanism of action. Research in gp41-membrane interactions, using peptides corresponding to specific functional domains, or constructs including several interactive domains, are reviewed here to get a better understanding of gp41 mediated virus-Cell fusion that can inform or guide the design of new HIV-1 fusion inhibitors.
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biochemistry and biophysics of hiv 1 gp41 membrane interactions and implications for hiv 1 envelope protein mediated Viral Cell fusion and fusion inhibitor design
2011Co-Authors: Lifeng Cai, Miriam Gochin, Keliang LiuAbstract:Human immunodeficiency virus type 1 (HIV-1), the pathogen of acquired immunodeficiency syndrome (AIDS), causes ∼2 millions death every year and still defies an effective vaccine. HIV-1 infects host Cells through envelope protein - mediated virus-Cell fusion. The transmembrane subunit of envelope protein, gp41, is the molecular machinery which facilitates fusion. Its ectodomain contains several distinguishing functional domains, fusion peptide (FP), Nterminal heptad repeat (NHR), C-terminal heptad repeat (CHR) and membrane proximal extraCellular region (MPER). During the fusion process, FP inserts into the host Cell membrane, and an extended gp41 prehairpin conformation bridges the Viral and Cell membranes through MPER and FP respectively. Subsequent conformational change of the unstable prehairpin results in a coiled-coil 6-helix bundle (6HB) structure formed between NHR and CHR. The energetics of 6HB formation drives membrane apposition and fusion. Drugs targeting gp41 functional domains to prevent 6HB formation inhibit HIV-1 infection. T20 (enfuvirtide, Fuzeon) was approved by the US FDA in 2003 as the first fusion inhibitor. It is a 36-residue peptide from the gp41 CHR, and it inhibits 6HB formation by targeting NHR and lipids. Development of new fusion inhibitors, especially small molecule drugs, is encouraged to overcome the shortcomings of T20 as a peptide drug. Hydrophobic characteristics and membrane association are critical for gp41 function and mechanism of action. Research in gp41-membrane interactions, using peptides corresponding to specific functional domains, or constructs including several interactive domains, are reviewed here to get a better understanding of gp41 mediated virus-Cell fusion that can inform or guide the design of new HIV-1 fusion inhibitors.
Sandor Belak - One of the best experts on this subject based on the ideXlab platform.
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molecular characterization of feline infectious peritonitis virus strain df 2 and studies of the role of orf3abc in Viral Cell tropism
2012Co-Authors: Adam Balint, Attila Farsang, Zoltan Zadori, Akos Hornyak, Laszlo Dencso, Fernando Almazan, Luis Enjuanes, Sandor BelakAbstract:The full-length genome of the highly lethal feline infectious peritonitis virus (FIPV) strain DF-2 was sequenced and cloned into a bacterial artificial chromosome (BAC) to study the role of ORF3abc in the FIPV-feline enteric coronavirus (FECV) transition. The reverse genetic system allowed the replacement of the truncated ORF3abc of the original FIPV DF-2 genome with the intact ORF3abc of the canine coronavirus (CCoV) reference strain Elmo/02. The in vitro replication kinetics of these two viruses was studied in CrFK and FCWF-4 Cell lines, as well as in feline peripheral blood monocytes. Both viruses showed similar replication kinetics in established Cell lines. However, the strain with a full-length ORF3 showed markedly lower replication of more than 2 log(10) titers in feline peripheral blood monocytes. Our results suggest that the truncated ORF3abc plays an important role in the efficient macrophage/monocyte tropism of type II FIPV.
Manfred Heinlein - One of the best experts on this subject based on the ideXlab platform.
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comparison of the oilseed rape mosaic virus and tobacco mosaic virus movement proteins mp reveals common and dissimilar mp functions for tobamovirus spread
2014Co-Authors: Annette Niehl, Adrien Pasquier, Inmaculada Ferriol, Yves Mely, Manfred HeinleinAbstract:Tobacco mosaic virus (TMV) is a longstanding model for studying virus movement and macromolecular transport through plasmodesmata (PD). Its movement protein (MP) interacts with cortical microtubule (MT)-associated ER sites (C-MERs) to facilitate the formation and transport of ER-associated Viral replication complexes (VRCs) along the ER-actin network towards PD. To investigate whether this movement mechanism might be conserved between tobamoviruses, we compared the functions of Oilseed rape mosaic virus (ORMV) MP with those of MPTMV. We show that MPORMV supports TMV movement more efficiently than MPTMV. Moreover, MPORMV localizes to C-MERs like MPTMV but accumulates to lower levels and does not localize to larger inclusions/VRCs or along MTs, patterns regularly seen for MPTMV. Our findings extend the role of C-MERs in Viral Cell-to-Cell transport to a virus commonly used for functional genomics in Arabidopsis. Moreover, accumulation of tobamoViral MP in inclusions or along MTs is not required for virus movement. (C) 2014 Elsevier Inc. All rights reserved.
Vitaly Citovsky - One of the best experts on this subject based on the ideXlab platform.
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biology of callose β 1 3 glucan turnover at plasmodesmata
2011Co-Authors: Raul Zavaliev, Shoko Ueki, Bernard L Epel, Vitaly CitovskyAbstract:The turnover of callose (β-1,3-glucan) within Cell walls is an essential process affecting many developmental, physiological and stress related processes in plants. The deposition and degradation of callose at the neck region of plasmodesmata (Pd) is one of the Cellular control mechanisms regulating Pd permeability during both abiotic and biotic stresses. Callose accumulation at Pd is controlled by callose synthases (CalS; EC 2.4.1.34), endogenous enzymes mediating callose synthesis, and by β-1,3-glucanases (BG; EC 3.2.1.39), hydrolytic enzymes which specifically degrade callose. Transcriptional and posttranslational regulation of some CalSs and BGs are strongly controlled by stress signaling, such as that resulting from pathogen invasion. We review the role of Pd-associated callose in the regulation of interCellular communication during developmental, physiological, and stress response processes. Special emphasis is placed on the involvement of Pd-callose in Viral pathogenicity. Callose accumulation at Pd restricts virus movement in both compatible and incompatible interactions, while its degradation promotes pathogen spread. Hence, studies on mechanisms of callose turnover at Pd during Viral Cell-to-Cell spread are of importance for our understanding of host mechanisms exploited by viruses in order to successfully spread within the infected plant.
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interaction between the tobacco mosaic virus movement protein and host Cell pectin methylesterases is required for Viral Cell to Cell movement
2000Co-Authors: Minhuei Chen, Jinsong Sheng, Geoffrey Hind, Avtar K Handa, Vitaly CitovskyAbstract:Virus-encoded movement protein (MP) mediates Cell-to-Cell spread of tobacco mosaic virus (TMV) through plant interCellular connections, the plasmodesmata. The molecular pathway by which TMV MP interacts with the host Cell is largely unknown. To understand this process better, a Cell wall-associated protein that specifically binds the Viral MP was purified from tobacco leaf Cell walls and identified as pectin methylesterase (PME). In addition to TMV MP, PME is recognized by MPs of turnip vein clearing virus (TVCV) and cauliflower mosaic virus (CaMV). The use of amino acid deletion mutants of TMV MP showed that its domain was necessary and sufficient for association with PME. Deletion of the PME-binding region resulted in inactivation of TMV Cell-to-Cell movement.
Keliang Liu - One of the best experts on this subject based on the ideXlab platform.
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biochemistry and biophysics of hiv 1 gp41 membrane interactions and implications for hiv 1 envelope protein mediated Viral Cell fusion and fusion inhibitor design
2011Co-Authors: Lifeng Cai, Miriam Gochin, Keliang LiuAbstract:Human immunodeficiency virus type 1 (HIV-1), the pathogen of acquired immunodeficiency syndrome (AIDS), causes ∼2 millions death every year and still defies an effective vaccine. HIV-1 infects host Cells through envelope protein - mediated virus-Cell fusion. The transmembrane subunit of envelope protein, gp41, is the molecular machinery which facilitates fusion. Its ectodomain contains several distinguishing functional domains, fusion peptide (FP), Nterminal heptad repeat (NHR), C-terminal heptad repeat (CHR) and membrane proximal extraCellular region (MPER). During the fusion process, FP inserts into the host Cell membrane, and an extended gp41 prehairpin conformation bridges the Viral and Cell membranes through MPER and FP respectively. Subsequent conformational change of the unstable prehairpin results in a coiled-coil 6-helix bundle (6HB) structure formed between NHR and CHR. The energetics of 6HB formation drives membrane apposition and fusion. Drugs targeting gp41 functional domains to prevent 6HB formation inhibit HIV-1 infection. T20 (enfuvirtide, Fuzeon) was approved by the US FDA in 2003 as the first fusion inhibitor. It is a 36-residue peptide from the gp41 CHR, and it inhibits 6HB formation by targeting NHR and lipids. Development of new fusion inhibitors, especially small molecule drugs, is encouraged to overcome the shortcomings of T20 as a peptide drug. Hydrophobic characteristics and membrane association are critical for gp41 function and mechanism of action. Research in gp41-membrane interactions, using peptides corresponding to specific functional domains, or constructs including several interactive domains, are reviewed here to get a better understanding of gp41 mediated virus-Cell fusion that can inform or guide the design of new HIV-1 fusion inhibitors.
