The Experts below are selected from a list of 144 Experts worldwide ranked by ideXlab platform
Simon Scheuring - One of the best experts on this subject based on the ideXlab platform.
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High-Speed Atomic Force Microscopy of ESCRT Protein Assembly
Biophysical Journal, 2015Co-Authors: Lorena Redondo, Nicolas Chiaruttini, Atsushi Miyagi, Adai Colom, Aurélien Roux, Simon ScheuringAbstract:The endosomal sorting complex required for transport (ESCRT) mediates membrane remodelling in cells. When ESCRT oligomerize, it is able to bud the membrane forming constriction necks that will break resulting in vesicular bodies or the viral envelope, to name a few of its implications. So far, relatively little is known about the molecular fine structure and less about the dynamics of ESCRT assembly, essential for our understanding how it deforms and cleaves the membrane.In this work, we used high-speed atomic force microscopy (HS-AFM) to study the ESCRT machinery, in particular the ESCRT-III complex, Snf7. HS-AFM allows simultaneous observation of structure, dynamics and function of biological assemblies, with nanometer spatial and sub-second temporal resolution. We show HS-AFM movies of the Snf7 complex formation and its dynamics from filament to the maturated circular assembly around the membrane constriction site. We observe interfilament dynamics that provide a basis for a mechanistic explanation how the machinery creates tension for membrane fission by a buckling mechanism.
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1773-Plat High-Speed Atomic Force Microscopy of ESCRT Protein Assembly
2015Co-Authors: Mary E. Hatcher, Lorena Redondo, Nicolas Chiaruttini, Atsushi Miyagi, Adai Colom, Mary Creedon, Simon ScheuringAbstract:of spectroscopic and calorimetric techniques was used to investigate the un-folding of both DNA molecules and polycation-DNA complexes, and to deter-mine their thermodynamic binding profiles. The resulting polycation-DNAcomplexes were stable in aqueous solution at room temperature. The bindingof each copolymer to DNA stabilized the helix-coil transition of all DNA mol-ecules, yielding binding affinities of ~104 M-1, which were lowered by theincrease in salt concentration. However, binding affinities of 105 were ob-tained with the ethhidium bromide displacement essay. Isothermal titrationcalorimetric experiments yielded negligible heats of interaction. Therefore,the favorable formation of the copolymer-DNA complexes is entropy drivenwhich was rationalized in terms of the release of both counterions and watermolecules upon complex formation. In summary, polycation binding to DNAwas found to be electrostatic in nature, i.e., the positively charged lysinegroups formed ion pairs with the negatively charged phosphate groupsof DNA. Supported by Grant MCB-1122029 from the National ScienceFoundation.1771-PlatCorrelating DrugBindingAffinitieswith Base Pair Opening Rates in DNAMary E. Hatcher
Lorena Redondo - One of the best experts on this subject based on the ideXlab platform.
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High-Speed Atomic Force Microscopy of ESCRT Protein Assembly
Biophysical Journal, 2015Co-Authors: Lorena Redondo, Nicolas Chiaruttini, Atsushi Miyagi, Adai Colom, Aurélien Roux, Simon ScheuringAbstract:The endosomal sorting complex required for transport (ESCRT) mediates membrane remodelling in cells. When ESCRT oligomerize, it is able to bud the membrane forming constriction necks that will break resulting in vesicular bodies or the viral envelope, to name a few of its implications. So far, relatively little is known about the molecular fine structure and less about the dynamics of ESCRT assembly, essential for our understanding how it deforms and cleaves the membrane.In this work, we used high-speed atomic force microscopy (HS-AFM) to study the ESCRT machinery, in particular the ESCRT-III complex, Snf7. HS-AFM allows simultaneous observation of structure, dynamics and function of biological assemblies, with nanometer spatial and sub-second temporal resolution. We show HS-AFM movies of the Snf7 complex formation and its dynamics from filament to the maturated circular assembly around the membrane constriction site. We observe interfilament dynamics that provide a basis for a mechanistic explanation how the machinery creates tension for membrane fission by a buckling mechanism.
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1773-Plat High-Speed Atomic Force Microscopy of ESCRT Protein Assembly
2015Co-Authors: Mary E. Hatcher, Lorena Redondo, Nicolas Chiaruttini, Atsushi Miyagi, Adai Colom, Mary Creedon, Simon ScheuringAbstract:of spectroscopic and calorimetric techniques was used to investigate the un-folding of both DNA molecules and polycation-DNA complexes, and to deter-mine their thermodynamic binding profiles. The resulting polycation-DNAcomplexes were stable in aqueous solution at room temperature. The bindingof each copolymer to DNA stabilized the helix-coil transition of all DNA mol-ecules, yielding binding affinities of ~104 M-1, which were lowered by theincrease in salt concentration. However, binding affinities of 105 were ob-tained with the ethhidium bromide displacement essay. Isothermal titrationcalorimetric experiments yielded negligible heats of interaction. Therefore,the favorable formation of the copolymer-DNA complexes is entropy drivenwhich was rationalized in terms of the release of both counterions and watermolecules upon complex formation. In summary, polycation binding to DNAwas found to be electrostatic in nature, i.e., the positively charged lysinegroups formed ion pairs with the negatively charged phosphate groupsof DNA. Supported by Grant MCB-1122029 from the National ScienceFoundation.1771-PlatCorrelating DrugBindingAffinitieswith Base Pair Opening Rates in DNAMary E. Hatcher
Markus Babst - One of the best experts on this subject based on the ideXlab platform.
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MVB vesicle formation: ESCRT-dependent, ESCRT-independent and everything in between.
Current opinion in cell biology, 2011Co-Authors: Markus BabstAbstract:Multivesicular bodies (MVBs) are endosomes that have internalized portions of the limiting membrane into the compartment, thereby forming intralumenal vesicles. This vesicle formation is unusual in that it is directed away from the cytoplasm, which requires a unique mechanism unlike any mechanism described for other vesicle formation events. The best contenders for the machinery that drives MVB vesicle formation are the ESCRT Protein complexes. However, increasing evidence suggests that lipids may play a key role in this membrane-deformation process. This review attempts to combine the seemingly contradictory findings into a MVB vesicle formation model that is based on a lipid-driven and ESCRT-regulated mechanism.
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Biochemical Analyses of Human IST1 and Its Function in Cytokinesis
Molecular biology of the cell, 2009Co-Authors: Monika Bajorek, Markus Babst, Eiji Morita, Jack J. Skalicky, Scott G. Morham, Wesley I. SundquistAbstract:The newly described yeast endosomal sorting complexes required for transport (ESCRT) Protein increased sodium tolerance-1 (Ist1p) binds the late-acting ESCRT Proteins Did2p/charged MVB Protein (CHMP) 1 and Vps4p and exhibits synthetic vacuolar Protein sorting defects when combined with mutations in the Vta1p/LIP5-Vps60p/CHMP5 complex. Here, we report that human IST1 also functions in the ESCRT pathway and is required for efficient abscission during HeLa cell cytokinesis. IST1 binding interactions with VPS4, CHMP1, LIP5, and ESCRT-I were characterized, and the IST1-VPS4 interaction was investigated in detail. Mutational and NMR spectroscopic studies revealed that the IST1 terminus contains two distinct MIT interacting motifs (MIM1 and MIM2) that wrap around and bind in different groves of the MIT helical bundle. IST1, CHMP1, and VPS4 were recruited to the midbodies of dividing cells, and depleting either IST1 or CHMP1 Proteins blocked VPS4 recruitment and abscission. In contrast, IST1 depletion did not inhibit human immunodeficiency virus-1 budding. Thus, IST1 and CHMP1 act together to recruit and modulate specific VPS4 activities required during the final stages of cell division.
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A Close-up of the ESCRTs
Developmental cell, 2006Co-Authors: Markus BabstAbstract:The ESCRT Protein complexes assemble on the endosome into a Protein network that sorts ubiquitinated transmembrane Proteins into lumenal vesicles of the compartment. New structural information highlights the complexity of the ESCRT network.
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A Protein's final ESCRT.
Traffic (Copenhagen Denmark), 2005Co-Authors: Markus BabstAbstract:In eukaryotic cells, delivery of transmembrane Proteins into the lumen of the lysosome for degradation is mediated by the multivesicular body pathway. The function of the ESCRT Protein complexes is required for both the formation of multivesicular body lumenal vesicles and the sorting of endosomal cargo Proteins into these vesicles. Recent studies have identified additional factors that seem to function as an upstream cargo retention system feeding into the ESCRT machinery, given new insights into the dynamic structure of multivesicular bodies, and identified a potential mechanism for multivesicular body vesicle formation.
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ESCRT iii an endosome associated heterooligomeric Protein complex required for mvb sorting
Developmental Cell, 2002Co-Authors: Markus Babst, David J Katzmann, Eden J Estepasabal, Timo Meerloo, Scott D EmrAbstract:The sorting of transmembrane Proteins (e.g., cell surface receptors) into the multivesicular body (MVB) pathway to the lysosomal/vacuolar lumen requires the function of the ESCRT Protein complexes. The soluble coiled-coil-containing Proteins Vps2, Vps20, Vps24, and Snf7 are recruited from the cytoplasm to endosomal membranes where they oligomerize into a Protein complex, ESCRT-III. ESCRT-III contains two functionally distinct subcomplexes. The Vps20-Snf7 subcomplex binds to the endosomal membrane, in part via the myristoyl group of Vps20. The Vps2-Vps24 subcomplex binds to the Vps20-Snf7 complex and thereby serves to recruit additional cofactors to this site of Protein sorting. We provide evidence for a role for ESCRT-III in sorting and/or concentration of MVB cargoes.
Arnim Pause - One of the best experts on this subject based on the ideXlab platform.
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Structure and functions of HD-PTP in receptor trafficking and cancer
Biochemistry and Cell Biology, 2018Co-Authors: Guillaume Desrochers, Jalal M Kazan, Arnim PauseAbstract:Cell surface receptors trigger the activation of signaling pathways to regulate key cellular processes, including cell survival and proliferation. Internalization, sorting and trafficking of activated receptors, therefore play a major role in the regulation and attenuation of cell signaling. Efficient sorting of endocytosed receptors is performed by the ESCRT machinery, which targets receptors for degradation by the sequential establishment of Protein complexes. These events are tightly regulated and malfunction of ESCRT components can lead to abnormal trafficking, sustained signaling and promote tumor formation or progression. In this review, we analyze the modular domain organization of the alternative ESCRT Protein HD-PTP and its role in receptor trafficking and tumorigenesis.
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Structure and functions of His domain Protein tyrosine phosphatase in receptor trafficking and cancer 1.
Biochemistry and cell biology = Biochimie et biologie cellulaire, 2018Co-Authors: Guillaume Desrochers, Jalal M Kazan, Arnim PauseAbstract:Cell surface receptors trigger the activation of signaling pathways to regulate key cellular processes, including cell survival and proliferation. Internalization, sorting, and trafficking of activated receptors, therefore, play a major role in the regulation and attenuation of cell signaling. Efficient sorting of endocytosed receptors is performed by the ESCRT machinery, which targets receptors for degradation by the sequential establishment of Protein complexes. These events are tightly regulated and malfunction of ESCRT components can lead to abnormal trafficking and sustained signaling and promote tumor formation or progression. In this review, we analyze the modular domain organization of the alternative ESCRT Protein HD-PTP and its role in receptor trafficking and tumorigenesis.
Nicolas Chiaruttini - One of the best experts on this subject based on the ideXlab platform.
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High-Speed Atomic Force Microscopy of ESCRT Protein Assembly
Biophysical Journal, 2015Co-Authors: Lorena Redondo, Nicolas Chiaruttini, Atsushi Miyagi, Adai Colom, Aurélien Roux, Simon ScheuringAbstract:The endosomal sorting complex required for transport (ESCRT) mediates membrane remodelling in cells. When ESCRT oligomerize, it is able to bud the membrane forming constriction necks that will break resulting in vesicular bodies or the viral envelope, to name a few of its implications. So far, relatively little is known about the molecular fine structure and less about the dynamics of ESCRT assembly, essential for our understanding how it deforms and cleaves the membrane.In this work, we used high-speed atomic force microscopy (HS-AFM) to study the ESCRT machinery, in particular the ESCRT-III complex, Snf7. HS-AFM allows simultaneous observation of structure, dynamics and function of biological assemblies, with nanometer spatial and sub-second temporal resolution. We show HS-AFM movies of the Snf7 complex formation and its dynamics from filament to the maturated circular assembly around the membrane constriction site. We observe interfilament dynamics that provide a basis for a mechanistic explanation how the machinery creates tension for membrane fission by a buckling mechanism.
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1773-Plat High-Speed Atomic Force Microscopy of ESCRT Protein Assembly
2015Co-Authors: Mary E. Hatcher, Lorena Redondo, Nicolas Chiaruttini, Atsushi Miyagi, Adai Colom, Mary Creedon, Simon ScheuringAbstract:of spectroscopic and calorimetric techniques was used to investigate the un-folding of both DNA molecules and polycation-DNA complexes, and to deter-mine their thermodynamic binding profiles. The resulting polycation-DNAcomplexes were stable in aqueous solution at room temperature. The bindingof each copolymer to DNA stabilized the helix-coil transition of all DNA mol-ecules, yielding binding affinities of ~104 M-1, which were lowered by theincrease in salt concentration. However, binding affinities of 105 were ob-tained with the ethhidium bromide displacement essay. Isothermal titrationcalorimetric experiments yielded negligible heats of interaction. Therefore,the favorable formation of the copolymer-DNA complexes is entropy drivenwhich was rationalized in terms of the release of both counterions and watermolecules upon complex formation. In summary, polycation binding to DNAwas found to be electrostatic in nature, i.e., the positively charged lysinegroups formed ion pairs with the negatively charged phosphate groupsof DNA. Supported by Grant MCB-1122029 from the National ScienceFoundation.1771-PlatCorrelating DrugBindingAffinitieswith Base Pair Opening Rates in DNAMary E. Hatcher