1
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King MR, Ruff KM, Pappu RV. Emergent microenvironments of nucleoli. Nucleus 2024; 15:2319957. [PMID: 38443761 PMCID: PMC10936679 DOI: 10.1080/19491034.2024.2319957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 02/13/2024] [Indexed: 03/07/2024] Open
Abstract
In higher eukaryotes, the nucleolus harbors at least three sub-phases that facilitate multiple functionalities including ribosome biogenesis. The three prominent coexisting sub-phases are the fibrillar center (FC), the dense fibrillar component (DFC), and the granular component (GC). Here, we review recent efforts in profiling sub-phase compositions that shed light on the types of physicochemical properties that emerge from compositional biases and territorial organization of specific types of macromolecules. We highlight roles played by molecular grammars which refers to protein sequence features including the substrate binding domains, the sequence features of intrinsically disordered regions, and the multivalence of these distinct types of domains / regions. We introduce the concept of a barcode of emergent physicochemical properties of nucleoli. Although our knowledge of the full barcode remains incomplete, we hope that the concept prompts investigations into undiscovered emergent properties and engenders an appreciation for how and why unique microenvironments control biochemical reactions.
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Affiliation(s)
- Matthew R. King
- Department of Biomedical Engineering and Center for Biomolecular Condensates, Washington University in St. Louis, Campus, MO, USA
| | - Kiersten M. Ruff
- Department of Biomedical Engineering and Center for Biomolecular Condensates, Washington University in St. Louis, Campus, MO, USA
| | - Rohit V. Pappu
- Department of Biomedical Engineering and Center for Biomolecular Condensates, Washington University in St. Louis, Campus, MO, USA
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2
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King MR, Ruff KM, Lin AZ, Pant A, Farag M, Lalmansingh JM, Wu T, Fossat MJ, Ouyang W, Lew MD, Lundberg E, Vahey MD, Pappu RV. Macromolecular condensation organizes nucleolar sub-phases to set up a pH gradient. Cell 2024; 187:1889-1906.e24. [PMID: 38503281 DOI: 10.1016/j.cell.2024.02.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 01/02/2024] [Accepted: 02/22/2024] [Indexed: 03/21/2024]
Abstract
Nucleoli are multicomponent condensates defined by coexisting sub-phases. We identified distinct intrinsically disordered regions (IDRs), including acidic (D/E) tracts and K-blocks interspersed by E-rich regions, as defining features of nucleolar proteins. We show that the localization preferences of nucleolar proteins are determined by their IDRs and the types of RNA or DNA binding domains they encompass. In vitro reconstitutions and studies in cells showed how condensation, which combines binding and complex coacervation of nucleolar components, contributes to nucleolar organization. D/E tracts of nucleolar proteins contribute to lowering the pH of co-condensates formed with nucleolar RNAs in vitro. In cells, this sets up a pH gradient between nucleoli and the nucleoplasm. By contrast, juxta-nucleolar bodies, which have different macromolecular compositions, featuring protein IDRs with very different charge profiles, have pH values that are equivalent to or higher than the nucleoplasm. Our findings show that distinct compositional specificities generate distinct physicochemical properties for condensates.
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Affiliation(s)
- Matthew R King
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Kiersten M Ruff
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Andrew Z Lin
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Avnika Pant
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Mina Farag
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Jared M Lalmansingh
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Tingting Wu
- Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Department of Electrical and Systems Engineering, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Martin J Fossat
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Wei Ouyang
- Department of Bioengineering, Schools of Engineering and Medicine, Stanford University, Stanford, CA, USA; Department of Pathology, School of Medicine, Stanford University, Stanford, CA, USA; Science for Life Laboratory, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH-Royal Institute of Technology, Stockholm, Sweden
| | - Matthew D Lew
- Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Department of Electrical and Systems Engineering, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Emma Lundberg
- Department of Bioengineering, Schools of Engineering and Medicine, Stanford University, Stanford, CA, USA; Department of Pathology, School of Medicine, Stanford University, Stanford, CA, USA; Science for Life Laboratory, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH-Royal Institute of Technology, Stockholm, Sweden
| | - Michael D Vahey
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Rohit V Pappu
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA.
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3
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Wu T, King MR, Farag M, Pappu RV, Lew MD. Single fluorogen imaging reveals distinct environmental and structural features of biomolecular condensates. bioRxiv 2023:2023.01.26.525727. [PMID: 36747818 PMCID: PMC9900924 DOI: 10.1101/2023.01.26.525727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Recent computations suggest that biomolecular condensates that form via macromolecular phase separation are network fluids featuring spatially inhomogeneous organization of the underlying molecules. Computations also point to unique conformations of molecules at condensate interfaces. Here, we test these predictions using high-resolution structural characterizations of condensates formed by intrinsically disordered prion-like low complexity domains (PLCDs). We leveraged the localization and orientational preferences of freely diffusing fluorogens and the solvatochromic effect whereby specific fluorogens are turned on in response to the physic-chemical properties of condensate microenvironments to facilitate single-molecule tracking and super-resolution imaging. We deployed three different fluorogens to probe internal microenvironments and molecular organization of PLCD condensates. The spatiotemporal resolution and environmental sensitivity afforded by single-fluorogen imaging shows that the internal environments of condensates are more hydrophobic than coexisting dilute phases. Molecules within condensates are organized in a spatially inhomogeneous manner featuring slow-moving nanoscale molecular clusters or hubs that coexist with fast-moving molecules. Finally, molecules at interfaces of condensates are found to have distinct orientational preferences when compared to the interiors. Our findings, which affirm computational predictions, help provide a structural basis for condensate viscoelasticity and dispel the notion of protein condensates being isotropic liquids defined by uniform internal densities.
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Affiliation(s)
- Tingting Wu
- Department of Electrical and Systems Engineering, Washington University in St. Louis, James F. McKelvey School of Engineering, Washington University in St. Louis; St. Louis, MO 63130, USA
- Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis; St. Louis, MO 63130, USA
| | - Matthew R King
- Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis; St. Louis, MO 63130, USA
- Department of Biomedical Engineering, Washington University in St. Louis, James F. McKelvey School of Engineering, Washington University in St. Louis; St. Louis, MO 63130, USA
| | - Mina Farag
- Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis; St. Louis, MO 63130, USA
- Department of Biomedical Engineering, Washington University in St. Louis, James F. McKelvey School of Engineering, Washington University in St. Louis; St. Louis, MO 63130, USA
| | - Rohit V Pappu
- Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis; St. Louis, MO 63130, USA
- Department of Biomedical Engineering, Washington University in St. Louis, James F. McKelvey School of Engineering, Washington University in St. Louis; St. Louis, MO 63130, USA
| | - Matthew D Lew
- Department of Electrical and Systems Engineering, Washington University in St. Louis, James F. McKelvey School of Engineering, Washington University in St. Louis; St. Louis, MO 63130, USA
- Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis; St. Louis, MO 63130, USA
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4
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Lin AZ, Ruff KM, Dar F, Jalihal A, King MR, Lalmansingh JM, Posey AE, Erkamp NA, Seim I, Gladfelter AS, Pappu RV. Dynamical control enables the formation of demixed biomolecular condensates. Nat Commun 2023; 14:7678. [PMID: 37996438 PMCID: PMC10667521 DOI: 10.1038/s41467-023-43489-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 11/10/2023] [Indexed: 11/25/2023] Open
Abstract
Cellular matter can be organized into compositionally distinct biomolecular condensates. For example, in Ashbya gossypii, the RNA-binding protein Whi3 forms distinct condensates with different RNA molecules. Using criteria derived from a physical framework for explaining how compositionally distinct condensates can form spontaneously via thermodynamic considerations, we find that condensates in vitro form mainly via heterotypic interactions in binary mixtures of Whi3 and RNA. However, within these condensates, RNA molecules become dynamically arrested. As a result, in ternary systems, simultaneous additions of Whi3 and pairs of distinct RNA molecules lead to well-mixed condensates, whereas delayed addition of an RNA component results in compositional distinctness. Therefore, compositional identities of condensates can be achieved via dynamical control, being driven, at least partially, by the dynamical arrest of RNA molecules. Finally, we show that synchronizing the production of different RNAs leads to more well-mixed, as opposed to compositionally distinct condensates in vivo.
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Affiliation(s)
- Andrew Z Lin
- Division of Biology and Biomedical Sciences, Plant and Microbial Biosciences, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Kiersten M Ruff
- Department of Biomedical Engineering and Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Furqan Dar
- Department of Biomedical Engineering and Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Ameya Jalihal
- Department of Cell Biology, Duke University, Durham, NC, 27708, USA
| | - Matthew R King
- Department of Biomedical Engineering and Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Jared M Lalmansingh
- Department of Biomedical Engineering and Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Ammon E Posey
- Department of Biomedical Engineering and Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Nadia A Erkamp
- Department of Biomedical Engineering and Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA
- Yusuf Hamied Department of Chemistry, Centre for Misfolding Diseases, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Ian Seim
- Department of Cell Biology, Duke University, Durham, NC, 27708, USA
| | - Amy S Gladfelter
- Department of Cell Biology, Duke University, Durham, NC, 27708, USA.
| | - Rohit V Pappu
- Division of Biology and Biomedical Sciences, Plant and Microbial Biosciences, Washington University in St. Louis, St. Louis, MO, 63130, USA.
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5
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Flynn AJ, Miller K, Codjoe JM, King MR, Haswell ES. Mechanosensitive ion channels MSL8, MSL9, and MSL10 have environmentally sensitive intrinsically disordered regions with distinct biophysical characteristics in vitro. Plant Direct 2023; 7:e515. [PMID: 37547488 PMCID: PMC10400277 DOI: 10.1002/pld3.515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 06/26/2023] [Accepted: 06/27/2023] [Indexed: 08/08/2023]
Abstract
Intrinsically disordered protein regions (IDRs) are highly dynamic sequences that rapidly sample a collection of conformations over time. In the past several decades, IDRs have emerged as a major component of many proteomes, comprising ~30% of all eukaryotic protein sequences. Proteins with IDRs function in a wide range of biological pathways and are notably enriched in signaling cascades that respond to environmental stresses. Here, we identify and characterize intrinsic disorder in the soluble cytoplasmic N-terminal domains of MSL8, MSL9, and MSL10, three members of the MscS-like (MSL) family of mechanosensitive ion channels. In plants, MSL channels are proposed to mediate cell and organelle osmotic homeostasis. Bioinformatic tools unanimously predicted that the cytosolic N-termini of MSL channels are intrinsically disordered. We examined the N-terminus of MSL10 (MSL10N) as an exemplar of these IDRs and circular dichroism spectroscopy confirms its disorder. MSL10N adopted a predominately helical structure when exposed to the helix-inducing compound trifluoroethanol (TFE). Furthermore, in the presence of molecular crowding agents, MSL10N underwent structural changes and exhibited alterations to its homotypic interaction favorability. Lastly, interrogations of collective behavior via in vitro imaging of condensates indicated that MSL8N, MSL9N, and MSL10N have sharply differing propensities for self-assembly into condensates, both inherently and in response to salt, temperature, and molecular crowding. Taken together, these data establish the N-termini of MSL channels as intrinsically disordered regions with distinct biophysical properties and the potential to respond uniquely to changes in their physiochemical environment.
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Affiliation(s)
- Aidan J. Flynn
- Department of BiologyWashington University in St. LouisSt. LouisMissouriUSA
- NSF Center for Engineering Mechanobiology, Department of BiologyWashington University in St. LouisSt. LouisMissouriUSA
- Department of Biochemistry and BiophysicsWashington University in St. LouisSt. LouisMissouriUSA
| | - Kari Miller
- Department of BiologyWashington University in St. LouisSt. LouisMissouriUSA
- NSF Center for Engineering Mechanobiology, Department of BiologyWashington University in St. LouisSt. LouisMissouriUSA
| | - Jennette M. Codjoe
- Department of BiologyWashington University in St. LouisSt. LouisMissouriUSA
- NSF Center for Engineering Mechanobiology, Department of BiologyWashington University in St. LouisSt. LouisMissouriUSA
| | - Matthew R. King
- Department of Biomedical EngineeringWashington University in St. LouisSt. LouisMissouriUSA
| | - Elizabeth S. Haswell
- Department of BiologyWashington University in St. LouisSt. LouisMissouriUSA
- NSF Center for Engineering Mechanobiology, Department of BiologyWashington University in St. LouisSt. LouisMissouriUSA
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6
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Gouveia B, Setru SU, King MR, Hamlin A, Stone HA, Shaevitz JW, Petry S. Acentrosomal spindles assemble from branching microtubule nucleation near chromosomes in Xenopus laevis egg extract. Nat Commun 2023; 14:3696. [PMID: 37344488 DOI: 10.1038/s41467-023-39041-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 05/08/2023] [Indexed: 06/23/2023] Open
Abstract
Microtubules are generated at centrosomes, chromosomes, and within spindles during cell division. Whereas microtubule nucleation at the centrosome is well characterized, much remains unknown about where, when, and how microtubules are nucleated at chromosomes. To address these questions, we reconstitute microtubule nucleation from purified chromosomes in meiotic Xenopus egg extract and find that chromosomes alone can form spindles. We visualize microtubule nucleation near chromosomes using total internal reflection fluorescence microscopy to find that this occurs through branching microtubule nucleation. By inhibiting molecular motors, we find that the organization of the resultant polar branched networks is consistent with a theoretical model where the effectors for branching nucleation are released by chromosomes, forming a concentration gradient that spatially biases branching microtbule nucleation. In the presence of motors, these branched networks are ultimately organized into functional spindles, where the number of emergent spindle poles scales with the number of chromosomes and total chromatin area.
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Affiliation(s)
- Bernardo Gouveia
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, 08544, USA
| | - Sagar U Setru
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, 08544, USA
| | - Matthew R King
- Department of Molecular Biology, Princeton University, Princeton, NJ, 08544, USA
| | - Aaron Hamlin
- Department of Molecular Biology, Princeton University, Princeton, NJ, 08544, USA
| | - Howard A Stone
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ, 08544, USA
| | - Joshua W Shaevitz
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, 08544, USA
- Department of Physics, Princeton University, Princeton, NJ, 08544, USA
| | - Sabine Petry
- Department of Molecular Biology, Princeton University, Princeton, NJ, 08544, USA.
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7
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Kraus J, Travis SM, King MR, Petry S. Augmin is a Ran-regulated spindle assembly factor. J Biol Chem 2023; 299:104736. [PMID: 37086784 DOI: 10.1016/j.jbc.2023.104736] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 04/03/2023] [Accepted: 04/05/2023] [Indexed: 04/24/2023] Open
Abstract
Mitotic spindles are composed of microtubules (MTs) that must nucleate at the right place and time. Ran regulates this process by directly controlling the release of spindle assembly factors (SAFs) from nucleocytoplasmic shuttle proteins importin-αβ and subsequently forms a biochemical gradient of SAFs localized around chromosomes. The majority of spindle MTs are generated by branching MT nucleation, which has been shown to require an eight-subunit protein complex known as augmin. InXenopus laevis, Ran can control branching through a canonical SAF, TPX2, which is non-essential in Drosophila melanogaster embryos and HeLa cells. Thus, how Ran regulates branching MT nucleation when TPX2 is not required remains unknown. Here, we use in vitro pulldowns and TIRF microscopy to show that augmin is a Ran-regulated SAF. We demonstrate that augmin directly interacts with both importin-α and importin-β through two nuclear localization sequences on the Haus8 subunit, which overlap with the MT binding site. Moreover, we show Ran controls localization of augmin to MTs in both Xenopus egg extract and in vitro. Our results demonstrate that RanGTP directly regulates augmin, which establishes a new way by which Ran controls branching MT nucleation and spindle assembly both in the absence and presence of TPX2.
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Affiliation(s)
- Jodi Kraus
- Department of Molecular Biology; Princeton University; Princeton, NJ, 08544; USA
| | - Sophie M Travis
- Department of Molecular Biology; Princeton University; Princeton, NJ, 08544; USA
| | - Matthew R King
- Department of Molecular Biology; Princeton University; Princeton, NJ, 08544; USA
| | - Sabine Petry
- Department of Molecular Biology; Princeton University; Princeton, NJ, 08544; USA.
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8
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Maan R, Reese L, Volkov VA, King MR, van der Sluis EO, Andrea N, Evers WH, Jakobi AJ, Dogterom M. Author Correction: Multivalent interactions facilitate motor-dependent protein accumulation at growing microtubule plus-ends. Nat Cell Biol 2023; 25:626. [PMID: 36922647 PMCID: PMC10104774 DOI: 10.1038/s41556-023-01124-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2023]
Affiliation(s)
- Renu Maan
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands
| | - Louis Reese
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands.,Physiology Course 2017, Marine Biological Laboratory, Woods Hole, MA, USA
| | - Vladimir A Volkov
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands.,Physiology Course 2017, Marine Biological Laboratory, Woods Hole, MA, USA.,School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK
| | - Matthew R King
- Physiology Course 2017, Marine Biological Laboratory, Woods Hole, MA, USA.,Department of Biomedical Engineering, Washington University in St. Louis, St Louis, MO, USA
| | - Eli O van der Sluis
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands
| | - Nemo Andrea
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands
| | - Wiel H Evers
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands
| | - Arjen J Jakobi
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands
| | - Marileen Dogterom
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands. .,Physiology Course 2017, Marine Biological Laboratory, Woods Hole, MA, USA.
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Pappu RV, Lin AZ, Ruff KM, Jalihal AP, Dar F, Posey AE, King MR, Lalmansingh JM, Gladfelter AS. Demixing of distinct ribonucleoprotein condensates is under dynamical control. Biophys J 2023; 122:443a. [PMID: 36784273 DOI: 10.1016/j.bpj.2022.11.2390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Affiliation(s)
- Rohit V Pappu
- Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Andrew Z Lin
- Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | | | - Ameya P Jalihal
- Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Furqan Dar
- Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Ammon E Posey
- Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Matthew R King
- Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Jared M Lalmansingh
- Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Amy S Gladfelter
- Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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10
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Lin AZ, Ruff KM, Jalihal A, Dar F, King MR, Lalmansingh JM, Posey AE, Seim I, Gladfelter AS, Pappu RV. Dynamical control enables the formation of demixed biomolecular condensates. Res Sq 2023:rs.3.rs-2440278. [PMID: 36798397 PMCID: PMC9934772 DOI: 10.21203/rs.3.rs-2440278/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Macromolecular phase separation underlies the regulated formation and dissolution of biomolecular condensates. What is unclear is how condensates of distinct and shared macromolecular compositions form and coexist within cellular milieus. Here, we use theory and computation to establish thermodynamic criteria that must be satisfied to achieve compositionally distinct condensates. We applied these criteria to an archetypal ribonucleoprotein condensate and discovered that demixing into distinct protein-RNA condensates cannot be the result of purely thermodynamic considerations. Instead, demixed, compositionally distinct condensates arise due to asynchronies in timescales that emerge from differences in long-lived protein-RNA and RNA-RNA crosslinks. This type of dynamical control is also found to be active in live cells whereby asynchronous production of molecules is required for realizing demixed protein-RNA condensates. We find that interactions that exert dynamical control provide a versatile and generalizable way to influence the compositions of coexisting condensates in live cells.
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Affiliation(s)
- Andrew Z Lin
- Division of Biology and Biomedical Sciences, Plant and Microbial Biosciences, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Kiersten M Ruff
- Department of Biomedical Engineering and Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Ameya Jalihal
- Department of Biology, University of North Carolina, Chapel Hill, NC
| | - Furqan Dar
- Department of Biomedical Engineering and Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Matthew R King
- Department of Biomedical Engineering and Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Jared M Lalmansingh
- Department of Biomedical Engineering and Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Ammon E Posey
- Department of Biomedical Engineering and Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Ian Seim
- Department of Biology, University of North Carolina, Chapel Hill, NC
| | - Amy S Gladfelter
- Department of Biology, University of North Carolina, Chapel Hill, NC
| | - Rohit V Pappu
- Department of Biomedical Engineering and Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
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11
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Lin AZ, Ruff KM, Jalihal A, Dar F, King MR, Lalmansingh JM, Posey AE, Seim I, Gladfelter AS, Pappu RV. Dynamical control enables the formation of demixed biomolecular condensates. bioRxiv 2023:2023.01.04.522702. [PMID: 36711465 PMCID: PMC9881950 DOI: 10.1101/2023.01.04.522702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Macromolecular phase separation underlies the regulated formation and dissolution of biomolecular condensates. What is unclear is how condensates of distinct and shared macromolecular compositions form and coexist within cellular milieus. Here, we use theory and computation to establish thermodynamic criteria that must be satisfied to achieve compositionally distinct condensates. We applied these criteria to an archetypal ribonucleoprotein condensate and discovered that demixing into distinct protein-RNA condensates cannot be the result of purely thermodynamic considerations. Instead, demixed, compositionally distinct condensates arise due to asynchronies in timescales that emerge from differences in long-lived protein-RNA and RNA-RNA crosslinks. This type of dynamical control is also found to be active in live cells whereby asynchronous production of molecules is required for realizing demixed protein-RNA condensates. We find that interactions that exert dynamical control provide a versatile and generalizable way to influence the compositions of coexisting condensates in live cells.
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12
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Maan R, Reese L, Volkov VA, King MR, van der Sluis EO, Andrea N, Evers WH, Jakobi AJ, Dogterom M. Multivalent interactions facilitate motor-dependent protein accumulation at growing microtubule plus-ends. Nat Cell Biol 2023; 25:68-78. [PMID: 36536175 PMCID: PMC9859754 DOI: 10.1038/s41556-022-01037-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 10/25/2022] [Indexed: 12/24/2022]
Abstract
Growing microtubule ends organize end-tracking proteins into comets of mixed composition. Here using a reconstituted fission yeast system consisting of end-binding protein Mal3, kinesin Tea2 and cargo Tip1, we found that these proteins can be driven into liquid-phase droplets both in solution and at microtubule ends under crowding conditions. In the absence of crowding agents, cryo-electron tomography revealed that motor-dependent comets consist of disordered networks where multivalent interactions may facilitate non-stoichiometric accumulation of cargo Tip1. We found that two disordered protein regions in Mal3 are required for the formation of droplets and motor-dependent accumulation of Tip1, while autonomous Mal3 comet formation requires only one of them. Using theoretical modelling, we explore possible mechanisms by which motor activity and multivalent interactions may lead to the observed enrichment of Tip1 at microtubule ends. We conclude that microtubule ends may act as platforms where multivalent interactions condense microtubule-associated proteins into large multi-protein complexes.
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Affiliation(s)
- Renu Maan
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands
| | - Louis Reese
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands.,Physiology Course 2017, Marine Biological Laboratory, Woods Hole, MA, USA
| | - Vladimir A Volkov
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands.,Physiology Course 2017, Marine Biological Laboratory, Woods Hole, MA, USA.,School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK
| | - Matthew R King
- Physiology Course 2017, Marine Biological Laboratory, Woods Hole, MA, USA.,Department of Biomedical Engineering, Washington University in St. Louis, St Louis, MO, USA
| | - Eli O van der Sluis
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands
| | - Nemo Andrea
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands
| | - Wiel H Evers
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands
| | - Arjen J Jakobi
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands
| | - Marileen Dogterom
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands. .,Physiology Course 2017, Marine Biological Laboratory, Woods Hole, MA, USA.
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13
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Cohoon TJ, King MR, Gharai F, Abolhoda A, Sakwa M, Shavelle DM. Attempted Cardiopulmonary Bypass Venous Cannula Extraction Catheter Extraction of a Rare Intracardiac Myoepithelioma. JACC Case Rep 2022; 7:101698. [PMID: 36776791 PMCID: PMC9911921 DOI: 10.1016/j.jaccas.2022.101698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Revised: 09/13/2022] [Accepted: 10/20/2022] [Indexed: 12/23/2022]
Abstract
Myoepithelioma of the soft tissue is a rare entity that can mimic myxoma when presenting within the heart. We present a case where cardiopulmonary bypass venous cannula extraction catheter removal of an intracardiac myoepithelioma was attempted with minimal debulking and subsequently required minimally invasive open-heart surgery with cardiopulmonary bypass. (Level of Difficulty: Advanced.).
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Affiliation(s)
- Travis J. Cohoon
- Division of Cardiology, University of California-Irvine, Orange, California, USA
| | - Matthew R. King
- Department of Medicine, University of California-Irvine, Orange, California, USA
| | - Fariba Gharai
- MemorialCare Heart and Vascular Institute, Long Beach Medical Center, Long Beach, California, USA
| | - Amir Abolhoda
- MemorialCare Heart and Vascular Institute, Long Beach Medical Center, Long Beach, California, USA
| | - Marc Sakwa
- MemorialCare Heart and Vascular Institute, Long Beach Medical Center, Long Beach, California, USA
| | - David M. Shavelle
- MemorialCare Heart and Vascular Institute, Long Beach Medical Center, Long Beach, California, USA,Address for correspondence: Dr David M. Shavelle, Department of Cardiology, Interventional Cardiology, MemorialCare Heart and Vascular Institute (MHVI), Long Beach Medical Center, 2801 Atlantic Avenue, Long Beach, California 90807, USA.
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14
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Safari MS, King MR, Brangwynne CP, Petry S. Interaction of spindle assembly factor TPX2 with importins-α/β inhibits protein phase separation. J Biol Chem 2021; 297:100998. [PMID: 34302807 PMCID: PMC8390506 DOI: 10.1016/j.jbc.2021.100998] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 07/12/2021] [Accepted: 07/20/2021] [Indexed: 12/30/2022] Open
Abstract
The microtubule-based mitotic spindle is responsible for equally partitioning the genome during each cell division, and its assembly is executed via several microtubule nucleation pathways. Targeting Protein for XKlp2 (TPX2) stimulates the branching microtubule nucleation pathway, where new microtubules are nucleated from preexisting ones within mitotic or meiotic spindles. TPX2, like other spindle assembly factors, is sequestered by binding to nuclear importins-α/β until the onset of mitosis, yet the molecular nature of this regulation remains unclear. Here we demonstrate that TPX2 interacts with importins-α/β with nanomolar affinity in a 1:1:1 monodispersed trimer. We also identify a new nuclear localization sequence in TPX2 that contributes to its high-affinity interaction with importin-α. In addition, we establish that TPX2 interacts with importin-β via dispersed, weak interactions. We show that interactions of both importin-α and -β with TPX2 inhibit its ability to undergo phase separation, which was recently shown to enhance the kinetics of branching microtubule nucleation. In summary, our study informs how importins regulate TPX2 to facilitate spindle assembly, and provides novel insight into the functional regulation of protein phase separation.
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Affiliation(s)
- Mohammad S Safari
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
| | - Matthew R King
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
| | - Clifford P Brangwynne
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey, USA; Howard Hughes Medical Institute, Princeton University, Princeton, New Jersey, USA
| | - Sabine Petry
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA.
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15
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King MR, Pappu RV. In Vitro Reconstitutions and Functional Characterizations of Fibrillar Centers of Nucleoli. Biophys J 2021. [DOI: 10.1016/j.bpj.2020.11.870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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16
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King MR, Anderson NJ, Deciu M, Guernsey LS, Cundiff M, Hajizadeh S, Jolivalt CG. Insulin deficiency, but not resistance, exaggerates cognitive deficits in transgenic mice expressing human amyloid and tau proteins. Reversal by Exendin-4 treatment. J Neurosci Res 2020; 98:2357-2369. [PMID: 32737929 DOI: 10.1002/jnr.24706] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 06/29/2020] [Accepted: 07/12/2020] [Indexed: 12/24/2022]
Abstract
Epidemiological studies have pointed at diabetes as a risk factor for Alzheimer's disease (AD) and this has been supported by several studies in animal models of both type 1 and type 2 diabetes. However, side-by-side comparison of the two types of diabetes is limited. We investigated the role of insulin deficiency and insulin resistance in the development of memory impairments and the effect of Exendin-4 (Ex4) treatment in a mouse model of AD. Three-4-month-old female wild type (WT) mice and mice overexpressing human tau and amyloid precursor protein (TAPP) were injected with streptozotocin (STZ) or fed a high-fat diet (HFD). A second study was performed in TAPP-STZ mice treated with Ex4, a long-lasting analog of GLP-1. Plasma and brain were collected at study termination for ELISA, Western blot, and immunohistochemistry analysis. Learning and memory deficits were impaired in TAPP transgenic mice compared with WT mice at the end of the study. Deficits were exaggerated by insulin deficiency in TAPP mice but 12 weeks of insulin resistance did not affect memory performances in either WT or TAPP mice. Levels of phosphorylated tau were increased in the brain of WT-STZ and TAPP-STZ mice but not in the brain of WT or TAPP mice on HFD. In the TAPP-STZ mice, treatment with Ex4 initiated after established cognitive deficits ameliorated learning, but not memory, impairments. This was accompanied by the reduction of amyloid β and phosphorylated tau expression. Theses studies support the role of Ex4 in AD, independently from its actions on diabetes.
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Affiliation(s)
- Matthew R King
- Department of Pathology, University of California San Diego, La Jolla, CA, USA
| | - Nicholas J Anderson
- Department of Pathology, University of California San Diego, La Jolla, CA, USA
| | - Mihaela Deciu
- Department of Pathology, University of California San Diego, La Jolla, CA, USA
| | - Lucie S Guernsey
- Department of Pathology, University of California San Diego, La Jolla, CA, USA
| | - Morgan Cundiff
- Department of Pathology, University of California San Diego, La Jolla, CA, USA
| | - Shohreh Hajizadeh
- Department of Pathology, University of California San Diego, La Jolla, CA, USA
| | - Corinne G Jolivalt
- Department of Pathology, University of California San Diego, La Jolla, CA, USA
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17
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Abstract
Phase separation of substrates and effectors is proposed to enhance biological reaction rates and efficiency. Targeting protein for Xklp2 (TPX2) is an effector of branching microtubule nucleation in spindles and functions with the substrate tubulin by an unknown mechanism. Here we show that TPX2 phase separates into a co-condensate with tubulin, which mediates microtubule nucleation in vitro and in isolated cytosol. TPX2-tubulin co-condensation preferentially occurs on pre-existing microtubules, the site of branching microtubule nucleation, at the endogenous and physiologically relevant concentration of TPX2. Truncation and chimera versions of TPX2 suggest that TPX2-tubulin co-condensation enhances the efficiency of TPX2-mediated branching microtubule nucleation. Finally, the known inhibitor of TPX2, the importin-α/β heterodimer, regulates TPX2 condensation in vitro and, consequently, branching microtubule nucleation activity in isolated cytosol. Our study demonstrates how regulated phase separation can simultaneously enhance reaction efficiency and spatially coordinate microtubule nucleation, which may facilitate rapid and accurate spindle formation.
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Affiliation(s)
- Matthew R King
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, 08544, USA
- Department of Biomedical Engineering, Washington University, Brauer Hall, One Brookings Drive, Saint Louis, Missouri, 63130, USA
| | - Sabine Petry
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, 08544, USA.
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18
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Song JG, King MR, Zhang R, Kadzik RS, Thawani A, Petry S. Mechanism of how augmin directly targets the γ-tubulin ring complex to microtubules. J Cell Biol 2018; 217:2417-2428. [PMID: 29875259 PMCID: PMC6028527 DOI: 10.1083/jcb.201711090] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 03/10/2018] [Accepted: 05/01/2018] [Indexed: 12/28/2022] Open
Abstract
Microtubules (MTs) must be generated from precise locations to form the structural frameworks required for cell shape and function. MTs are nucleated by the γ-tubulin ring complex (γ-TuRC), but it remains unclear how γ-TuRC gets to the right location. Augmin has been suggested to be a γ-TuRC targeting factor and is required for MT nucleation from preexisting MTs. To determine augmin's architecture and function, we purified Xenopus laevis augmin from insect cells. We demonstrate that augmin is sufficient to target γ-TuRC to MTs by in vitro reconstitution. Augmin is composed of two functional parts. One module (tetramer-II) is necessary for MT binding, whereas the other (tetramer-III) interacts with γ-TuRC. Negative-stain electron microscopy reveals that both tetramers fit into the Y-shape of augmin, and MT branching assays reveal that both are necessary for MT nucleation. The finding that augmin can directly bridge MTs with γ-TuRC via these two tetramers adds to our mechanistic understanding of how MTs can be nucleated from preexisting MTs.
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Affiliation(s)
- Jae-Geun Song
- Department of Molecular Biology, Princeton University, Princeton, NJ
| | - Matthew R King
- Department of Molecular Biology, Princeton University, Princeton, NJ
| | - Rui Zhang
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO
| | - Rachel S Kadzik
- Department of Molecular Biology, Princeton University, Princeton, NJ
| | - Akanksha Thawani
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ
| | - Sabine Petry
- Department of Molecular Biology, Princeton University, Princeton, NJ
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19
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McCarty OJT, Ku D, Sugimoto M, King MR, Cosemans JMEM, Neeves KB. Dimensional analysis and scaling relevant to flow models of thrombus formation: communication from the SSC of the ISTH. J Thromb Haemost 2016; 14:619-22. [PMID: 26933837 PMCID: PMC4829115 DOI: 10.1111/jth.13241] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 12/08/2015] [Indexed: 01/31/2023]
Affiliation(s)
- O J T McCarty
- Department of Biomedical Engineering, Oregon Health and Science University, Portland, OR
| | - D Ku
- GW Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - M Sugimoto
- Department of Regulatory Medicine for Thrombosis, Nara Medical University, Nara, Japan
| | - M R King
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - J M E M Cosemans
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, the Netherlands
| | - K B Neeves
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, CO, USA
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20
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King MR, Anderson NJ, Liu C, Law E, Cundiff M, Mixcoatl-Zecuatl TM, Jolivalt CG. Activation of the insulin-signaling pathway in sciatic nerve and hippocampus of type 1 diabetic rats. Neuroscience 2015; 303:220-8. [PMID: 26149351 DOI: 10.1016/j.neuroscience.2015.06.060] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 06/24/2015] [Accepted: 06/26/2015] [Indexed: 12/20/2022]
Abstract
Peripheral neuropathy is a major complication associated with diabetes and central neuropathy characterized by Alzheimer's disease-like features in the brain is associated with increased dementia risk for patients with diabetes. Although glucose uptake into the cells of the nervous system is insulin-independent, contribution of impaired insulin support is clearly recognized to play a role, however not yet fully understood, in the development of neuropathy. In this study, we assessed the direct role of insulin on the peripheral nervous system (PNS) and central nervous system (CNS) of insulin-dependent type 1 diabetic rats. Fresh sciatic nerve and hippocampus from control and diabetic rats were incubated with varied ex vivo concentrations of insulin and phosphorylation levels of insulin receptor and glycogen synthase kinase-3 (GSK3β) were assessed by Western blot analysis. Both the sciatic nerve and hippocampus from type 1 diabetic rats were highly responsive to exogenous insulin with a significantly increased phosphorylation of insulin receptor and GSK3 compared to tissues from control rats. Further, sustained in vivo insulin delivery, not sufficient to restore normal blood glucose, normalized the activation of both insulin receptor and GSK3 in both PNS and CNS tissues. These results suggest that the insulin-signaling pathway is responsive to exogenous insulin in the nervous system of insulin-deficient type 1 diabetic rats and that constant insulin delivery restore normal nerve function and may protect PNS and CNS from damage.
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Affiliation(s)
- M R King
- University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - N J Anderson
- University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - C Liu
- University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - E Law
- University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - M Cundiff
- University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | | | - C G Jolivalt
- University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA.
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21
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Anderson NJ, King MR, Delbruck L, Jolivalt CG. Role of insulin signaling impairment, adiponectin and dyslipidemia in peripheral and central neuropathy in mice. Dis Model Mech 2014; 7:625-33. [PMID: 24764191 PMCID: PMC4036470 DOI: 10.1242/dmm.015750] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
One of the tissues or organs affected by diabetes is the nervous system, predominantly the peripheral system (peripheral polyneuropathy and/or painful peripheral neuropathy) but also the central system with impaired learning, memory and mental flexibility. The aim of this study was to test the hypothesis that the pre-diabetic or diabetic condition caused by a high-fat diet (HFD) can damage both the peripheral and central nervous systems. Groups of C57BL6 and Swiss Webster mice were fed a diet containing 60% fat for 8 months and compared to control and streptozotocin (STZ)-induced diabetic groups that were fed a standard diet containing 10% fat. Aspects of peripheral nerve function (conduction velocity, thermal sensitivity) and central nervous system function (learning ability, memory) were measured at assorted times during the study. Both strains of mice on HFD developed impaired glucose tolerance, indicative of insulin resistance, but only the C57BL6 mice showed statistically significant hyperglycemia. STZ-diabetic C57BL6 mice developed learning deficits in the Barnes maze after 8 weeks of diabetes, whereas neither C57BL6 nor Swiss Webster mice fed a HFD showed signs of defects at that time point. By 6 months on HFD, Swiss Webster mice developed learning and memory deficits in the Barnes maze test, whereas their peripheral nervous system remained normal. In contrast, C57BL6 mice fed the HFD developed peripheral nerve dysfunction, as indicated by nerve conduction slowing and thermal hyperalgesia, but showed normal learning and memory functions. Our data indicate that STZ-induced diabetes or a HFD can damage both peripheral and central nervous systems, but learning deficits develop more rapidly in insulin-deficient than in insulin-resistant conditions and only in Swiss Webster mice. In addition to insulin impairment, dyslipidemia or adiponectinemia might determine the neuropathy phenotype.
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Affiliation(s)
- Nicholas J Anderson
- School of Medicine, Department of Pathology, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Matthew R King
- School of Medicine, Department of Pathology, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Lina Delbruck
- School of Medicine, Department of Pathology, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Corinne G Jolivalt
- School of Medicine, Department of Pathology, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA.
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22
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King MR, Matzat LH, Dale RK, Lim SJ, Lei EP. The RNA-binding protein Rumpelstiltskin antagonizes gypsy chromatin insulator function in a tissue-specific manner. J Cell Sci 2014; 127:2956-66. [PMID: 24706949 DOI: 10.1242/jcs.151126] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Chromatin insulators are DNA-protein complexes that are situated throughout the genome that are proposed to contribute to higher-order organization and demarcation into distinct transcriptional domains. Mounting evidence in different species implicates RNA and RNA-binding proteins as regulators of chromatin insulator activities. Here, we identify the Drosophila hnRNP M homolog Rumpelstiltskin (Rump) as an antagonist of gypsy chromatin insulator enhancer-blocking and barrier activities. Despite ubiquitous expression of Rump, decreasing Rump levels leads to improvement of barrier activity only in tissues outside of the central nervous system (CNS). Furthermore, rump mutants restore insulator body localization in an insulator mutant background only in non-CNS tissues. Rump associates physically with core gypsy insulator proteins, and chromatin immunoprecipitation and sequencing analysis of Rump demonstrates extensive colocalization with a subset of insulator sites across the genome. The genome-wide binding profile and tissue specificity of Rump contrast with that of Shep, a recently identified RNA-binding protein that antagonizes gypsy insulator activity primarily in the CNS. Our findings indicate parallel roles for RNA-binding proteins in mediating tissue-specific regulation of chromatin insulator activity.
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Affiliation(s)
- Matthew R King
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Leah H Matzat
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Ryan K Dale
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Su Jun Lim
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Elissa P Lei
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
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23
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Neeves KB, McCarty OJT, Reininger AJ, Sugimoto M, King MR. Flow-dependent thrombin and fibrin generation in vitro: opportunities for standardization: communication from SSC of the ISTH. J Thromb Haemost 2014; 12:418-20. [PMID: 24330648 DOI: 10.1111/jth.12482] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Accepted: 12/03/2013] [Indexed: 11/30/2022]
Affiliation(s)
- K B Neeves
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, CO, USA
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24
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Li J, Guillebon AD, Hsu JW, Barthel SR, Dimitroff CJ, Lee YF, King MR. Human fucosyltransferase 6 enables prostate cancer metastasis to bone. Br J Cancer 2013. [DOI: 10.1038/bjc.2013.690 bjc2013690 [pii]] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
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25
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King MR, Anderson NJ, Guernsey LS, Jolivalt CG. Glycogen synthase kinase-3 inhibition prevents learning deficits in diabetic mice. J Neurosci Res 2013; 91:506-14. [PMID: 23362012 DOI: 10.1002/jnr.23192] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Revised: 10/29/2012] [Accepted: 11/21/2012] [Indexed: 12/20/2022]
Abstract
There is an increasing awareness that diabetes has an impact on the central nervous system, with reports of impaired learning, memory, and mental flexibility being more common in diabetic subjects than in the general population. Insulin-deficient diabetic mice also display learning deficits associated with defective insulin-signaling in the brain and increased activity of GSK3. In the present study, AR-A014418, a GSK3β inhibitor, and TX14(A), a neurotrophic factor with GSK3 inhibitory properties, were tested against the development of learning deficits in mice with insulin-deficient diabetes. Treatments were started at onset of diabetes and continued for 10 weeks. Treatment with AR-A014418 or TX14(A) prevented the development of learning deficits, assessed by the Barnes maze, but only AR-A014418 prevented memory deficits, as assessed by the object recognition test. Diabetes-induced increased levels of amyloid β protein and phosphorylated tau were not significantly affected by the treatments. However, the diabetes-induced decrease in synaptophysin, a presynaptic protein marker of hippocampal plasticity, was partially prevented by both treatments. These results suggest a role for GSK3 and/or reduced neurotrophic support in the development of cognitive deficits in diabetic mice that are associated with synaptic damage.
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Affiliation(s)
- Matthew R King
- Department of Pathology, School of Medicine, University of California San Diego, La Jolla, California, USA
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26
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Roest M, Reininger A, Zwaginga JJ, King MR, Heemskerk JWM. Flow chamber-based assays to measure thrombus formation in vitro: requirements for standardization. J Thromb Haemost 2011; 9:2322-4. [PMID: 22947397 DOI: 10.1111/j.1538-7836.2011.04492.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- M Roest
- Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, the Netherlands.
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27
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Huang Z, King MR. An immobilized nanoparticle-based platform for efficient gene knockdown of targeted cells in the circulation. Gene Ther 2009; 16:1271-82. [DOI: 10.1038/gt.2009.76] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Zwaginga JJ, Sakariassen KS, King MR, Diacovo TG, Grabowski EF, Nash G, Hoylaerts M, Heemskerk JWM. Can blood flow assays help to identify clinically relevant differences in von Willebrand factor functionality in von Willebrand disease types 1-3? J Thromb Haemost 2007; 5:2547-9. [PMID: 17944987 DOI: 10.1111/j.1538-7836.2007.02807.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Affiliation(s)
- J J Zwaginga
- Department of Experimental Immunohaematology, Sanquin Research, Amsterdam, The Netherlands.
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Zwaginga JJ, Sakariassen KS, Nash G, King MR, Heemskerk JW, Frojmovic M, Hoylaerts MF. Flow-based assays for global assessment of hemostasis. Part 2: current methods and considerations for the future. J Thromb Haemost 2006; 4:2716-7. [PMID: 16938128 DOI: 10.1111/j.1538-7836.2006.02178.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- J J Zwaginga
- Department of Experimental Immunohaematology Sanquin Research Amsterdam, and Immunohaematology Bloodtransfusion, University Hospital Leiden, Leiden, The Netherlands
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Zwaginga JJ, Nash G, King MR, Heemskerk JWM, Frojmovic M, Hoylaerts MF, Sakariassen KS. Flow-based assays for global assessment of hemostasis. Part 1: Biorheologic considerations. J Thromb Haemost 2006; 4:2486-7. [PMID: 16938127 DOI: 10.1111/j.1538-7836.2006.02177.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- J J Zwaginga
- Department of Experimental Immunohaematology Sanquin Research Amsterdam, and Immunohaematology Bloodtransfusion, University Hospital Leiden, Leiden, The Netherlands
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Kleinman SH, Glynn SA, Higgins MJ, Triulzi DJ, Smith JW, Nass CC, Garratty G, Murphy EL, LeParc GF, Schreiber GB, King MR, Chamberland ME, Nemo GJ. The RADAR repository: a resource for studies of infectious agents and their transmissibility by transfusion. Transfusion 2005; 45:1073-83. [PMID: 15987350 DOI: 10.1111/j.1537-2995.2005.00171.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND An ongoing issue in transfusion medicine is whether newly identified or emerging pathogens can be transmitted by transfusion. One method to study this question is through the use of a contemporary linked donor-recipient repository. STUDY DESIGN AND METHODS The Retrovirus Epidemiology Donor Study Allogeneic Donor and Recipient (RADAR) repository was established between 2000 and 2003 by seven blood centers and eight collaborating hospitals. Specimens from consented donors were collected, components from their donations were routed to participating hospitals, and recipients of these units gave enrollment and follow-up specimens for long-term storage. The repository was designed to show that zero transmissions to enrolled recipients would indicate with 95 percent confidence that the transfusion transmission rate of an agent with prevalence of 0.05 to 1 percent was lower than 25 percent. RESULTS The repository contains pre- and posttransfusion specimens from 3,575 cardiac, vascular, and orthopedic surgery patients, linked to 13,201 donation specimens. The mean number of RADAR donation exposures per recipient is 3.85. The distribution of components transfused is 77 percent red cells, 13 percent whole blood-derived platelet concentrates, and 10 percent fresh frozen plasma. A supplementary unlinked donation repository containing 99,906 specimens from 84,339 donors was also established and can be used to evaluate the prevalence of an agent and validate assay(s) performance before accessing the donor-recipient-linked repository. Recipient testing conducted during the establishment of RADAR revealed no transmissions of human immunodeficiency virus, hepatitis C virus, or human T-lymphotropic virus. CONCLUSIONS RADAR is a contemporary donor-recipient repository that can be accessed to study the transfusion transmissibility of emerging agents.
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Abstract
Aspects of neutrophil mechanical behavior relevant to the formation of adhesive contacts were assessed by measuring the dependence of the contact area between the cell and a spherical substrate under controlled loading. Micropipettes were used to bring neutrophils into contact with spherical beads under known forces, and the corresponding contact area was measured over time. The neutrophil was modeled as a viscous liquid drop with a constant cortical tension. Both the equilibrium state and the dynamics of the approach to equilibrium were examined. The equilibrium contact area increased monotonically with force in a manner consistent with a cell cortical tension of 16-24 pN/microm. The dynamic response matched predictions based on a model of the cell as a growing drop using published values for the effective viscosity of the cell. The contact pressure between the cell and substrate at equilibrium is predicted to depend on the curvature of the contacting substrate, but to be independent of the impingement force. The approach to equilibrium was rapid, such that the time-averaged stress for a two-second impingement was within 20% of the equilibrium value. These results have implications for the role of mechanical force in the formation of adhesive contacts.
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Affiliation(s)
- E B Lomakina
- Department of Pharmacology and Physiology, University of Rochester, Rochester, New York 14642, USA
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Abstract
The slow rolling motion of leukocytes along the walls of blood vessels mediated by specific receptor-ligand adhesion is important in inflammation and occurs in postcapillary venules over a wide range of wall shear stresses and vessel diameters. The ability of hydrodynamic collisions between cells to induce capture of free-stream leukocytes to a selectin-bearing surface under shear flow was studied experimentally by using a cell-free assay. It was found that carbohydrate-coated spherical beads, representing model leukocytes, tend to attach to the adhesive wall 4-5 cell diameters up- or downstream of a slowly rolling or stationary adhesive bead. A key feature of such "hydrodynamic recruitment" is that only glancing, indirect collisions occurring close to the plane will result in downstream attachment. A direct numerical simulation of cell capture and rolling that includes multiparticle hydrodynamic interactions is shown to reproduce the observed behavior accurately. The theory predicts that hydrodynamic recruitment will occur in the absence of buoyancy effects and over a range of shear rates, suggesting that the mechanism may be important in vivo. This theory is supported by measurements of leukocyte capture in vivo using the hamster cheek pouch model.
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Affiliation(s)
- M R King
- Departments of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
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Parr AC, West JB, King MR, Ueda K, Dehmer PM, Dehmer JL. Vibrational Branching Ratios and Asymmetry Parameters in the Photoionization of CO2 in the Region Between 650 Å and 840 Å. J Res Natl Inst Stand Technol 2001; 106:795-822. [PMID: 27500048 PMCID: PMC4862820 DOI: 10.6028/jres.106.038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/05/2001] [Indexed: 05/12/2023]
Abstract
The vibrational branching ratios and asymmetry parameters for CO2 have been determined in the wavelength region of 650 Å to near the ionization onset at about 840 Å. The study was performed using synchrotron radiation from the Daresbury storage ring that was dispersed with a 5 m grating monochomator that afforded resolution of 0.1 Å to 0.2 Å. This resolution allowed the study of the branching ratios and asymmetry parameters with enough detail to see the changes in the parameters within the pronounced autoionization structure in CO2 in this wavelength region. While the electron spectrometer resolution was not sufficient to resolve the spin orbit and Renner-Teller splitting in the photoelectron spectra, we are able to fit the data with a model that identifies the major structure in terms of the symmetric stretch and elements of the asymmetric stretch and bending modes. A calculation of the expected relative vibrational excitations based upon the Franck-Condon principle clearly showed non-Franck-Condon behavior in some of the vibrational-electronic transitions.
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Affiliation(s)
- A C Parr
- National Institute of Standards and Technology, Gaithersburg, MD 20899-8440, USA
| | - J B West
- Daresbury Laboratory, Warrington, WA4 4AD, UK
| | - M R King
- Daresbury Laboratory, Warrington, WA4 4AD, UK
| | - K Ueda
- Research Institute for Scientific Measurements, Tohoku University, Sendai 980, Japan
| | - P M Dehmer
- Office of Basic Energy Science, U.S. Department of Energy, Germantown, MD 20874, USA
| | - J L Dehmer
- National Science Foundation, 4201 Wilson Blvd., Arlington, VA 22230, USA
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Abstract
A novel numerical simulation of adhesive particles (cells) reversibly interacting with an adhesive surface under flow is presented. Particle--particle and particle--wall hydrodynamic interactions in low Reynolds number Couette flow are calculated using a boundary element method that solves an integral representation of the Stokes equation. Molecular bonds between surfaces are modeled as linear springs and stochastically formed and broken according to postulated descriptions of force-dependent kinetics. The resulting simulation, Multiparticle Adhesive Dynamics, is applied to the problem of selectin-mediated rolling of hard spheres coated with leukocyte adhesion molecules (cell-free system). Simulation results are compared to flow chamber experiments performed with carbohydrate-coated spherical beads rolling on P-selectin. Good agreement is found between theory and experiment, with the main observation being a decrease in rolling velocity with increasing concentration of rolling cells or increasing proximity between rolling cells. Pause times are found to increase and deviation motion is found to decrease as pairs of rolling cells become closer together or align with the flow.
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Affiliation(s)
- M R King
- Department of Chemical Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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Abstract
The purpose of this nested case-control study was to estimate the risk of SIL development among a cohort of women providing cervical samples as part of their family planning visit at baseline in 1991-1992. All women had normal cervical cytology (N = 2905) at baseline and provided a cervical sample for subsequent HPV typing. Among this cohort, 426 women developed SIL (22 HSIL and 404 LSIL), 619 developed atypia, and 1860 remained cytologically normal. Two controls per case were sampled from those who remained normal. PCR-based methods with L1 consensus primers were used to assess high-risk HPV positivity. Having an oncogenic HPV type at baseline was associated with an almost fourfold increased risk of HSIL development (relative risk (RR) = 3.8; 95% CI, 1.5--9.0) and a 70% increased risk of LSIL development (RR = 1.7; 95% CI, 1.2--2.3%). The association between HPV positivity and SIL development was strongest in the first year of follow-up (RR = 9.2 for HSIL and 2.5 for LSIL development). The decline in HPV-associated SIL risk may be a function of having only one measure of HPV positivity (at baseline).
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Affiliation(s)
- A L Coker
- Department of Epidemiology and Biostatistics, School of Medicine, University of South Carolina, Columbia, 29208, USA
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Baker JO, King MR, Adney WS, Decker SR, Vinzant TB, Lantz SE, Nieves RE, Thomas SR, Li LC, Cosgrove DJ, Himmel ME. Investigation of the cell-wall loosening protein expansin as a possible additive in the enzymatic saccharification of lignocellulosic biomass. Appl Biochem Biotechnol 2000; 84-86:217-23. [PMID: 10849790 DOI: 10.1385/abab:84-86:1-9:217] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- J O Baker
- Biotechnology Center for Fuels and Chemicals, National Renewable Energy Laboratory, Golden, CO 80401, USA.
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Abstract
BACKGROUND Past studies that have addressed the health effects of intimate partner violence (IPV) have defined IPV as violence based on physical blows that frequently cause injuries. To our knowledge, no epidemiologic research has assessed the physical health consequences of psychological forms of IPV. OBJECTIVE To estimate IPV prevalence by type and associated physical health consequences among women seeking primary health care. DESIGN Cross-sectional survey. SETTING AND PARTICIPANTS A total of 1152 women, aged 18 to 65 years, recruited from family practice clinics from February 1997 through January 1999 and screened for IPV during a brief in-clinic interview; health history and current status were assessed in a follow-up interview. RESULTS Of 1152 women surveyed, 53.6% ever experienced any type of partner violence; 13.6% experienced psychological IPV without physical IPV. Women experiencing psychological IPV were significantly more likely to report poor physical and mental health (adjusted relative risk [RR], 1.69 for physical health and 1.74 for mental health). Psychological IPV was associated with a number of adverse health outcomes, including a disability preventing work (adjusted RR, 1.49), arthritis (adjusted RR, 1.67), chronic pain (adjusted RR, 1.91), migraine (adjusted RR, 1.54) and other frequent headaches (adjusted RR, 1.41), stammering (adjusted RR, 2.31), sexually transmitted infections (adjusted RR, 1.82), chronic pelvic pain (adjusted RR, 1.62), stomach ulcers (adjusted RR, 1.72), spastic colon (adjusted RR, 3.62), and frequent indigestion, diarrhea, or constipation (adjusted RR, 1.30). Psychological IPV was as strongly associated with the majority of adverse health outcomes as was physical IPV. CONCLUSIONS Psychological IPV has significant physical health consequences. To reduce the range of health consequences associated with IPV, clinicians should screen for psychological forms of IPV as well as physical and sexual IPV.
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Affiliation(s)
- A L Coker
- Department of Epidemiology and Biostatistics, University of South Carolina, School of Public Health, Columbia 29208, USA.
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Egan JM, Webber MG, King MR, Boyd M, du Preez-Wilkinson G, Brock D. The hospitalist: a third alternative. Med J Aust 2000; 172:335-8. [PMID: 10844922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
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von Gruenigen VE, Coleman RL, King MR, Miller DS. Abdominal compartment syndrome in gynecologic surgery. Obstet Gynecol 1999; 94:830-2. [PMID: 10546746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
BACKGROUND Abdominal compartment syndrome is a rare condition in which increased intra-abdominal pressure adversely affects perfusion and viability of the viscera, and the cardiovascular, respiratory, and renal systems. The syndrome follows acute abdominal events such as abdominal trauma, intraperitoneal hemorrhage, or intra-abdominal infection. CASES Two women who had abdominal hysterectomies postoperatively developed clinical features of multisystem failure with markedly elevated intra-abdominal pressures. The women, one with intra-abdominal infection and diffuse intestinal edema and one with intra-abdominal hemorrhage, were diagnosed by clinical exam and intravesical pressure measurements. Both had follow-up exploration and temporary placement of the small bowel and colon into an intestinal bag until adequate resuscitation was achieved. CONCLUSION Abdominal compartment syndrome is a rare complication in gynecology that can be diagnosed early and decompressed promptly.
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Affiliation(s)
- V E von Gruenigen
- Department of Obstetrics and Gynecology, The University of Texas Southwestern Medical Center, Dallas 75235-9032, USA
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Cann IK, Kocherginskaya S, King MR, White BA, Mackie RI. Molecular cloning, sequencing, and expression of a novel multidomain mannanase gene from Thermoanaerobacterium polysaccharolyticum. J Bacteriol 1999; 181:1643-51. [PMID: 10049399 PMCID: PMC93557 DOI: 10.1128/jb.181.5.1643-1651.1999] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The manA gene of Thermoanaerobacterium polysaccharolyticum was cloned in Escherichia coli. The open reading frame of manA is composed of 3,291 bases and codes for a preprotein of 1,097 amino acids with an estimated molecular mass of 119,627 Da. The start codon is preceded by a strong putative ribosome binding site (TAAGGCGGTG) and a putative -35 (TTCGC) and -10 (TAAAAT) promoter sequence. The ManA of T. polysaccharolyticum is a modular protein. Sequence comparison and biochemical analyses demonstrate the presence of an N-terminal leader peptide, and three other domains in the following order: a putative mannanase-cellulase catalytic domain, cellulose binding domains 1 (CBD1) and CBD2, and a surface-layer-like protein region (SLH-1, SLH-2, and SLH-3). The CBD domains show no sequence homology to any cellulose binding domain yet reported, hence suggesting a novel CBD. The duplicated CBDs, which lack a disulfide bridge, exhibit 69% identity, and their deletion resulted in both failure to bind to cellulose and an apparent loss of carboxymethyl cellulase and mannanase activities. At the C-terminal region of the gene are three repeats of 59, 67, and 56 amino acids which are homologous to conserved sequences found in the S-layer-associated regions within the xylanases and cellulases of thermophilic members of the Bacillus-Clostridium cluster. The ManA of T. polysaccharolyticum, besides being an extremely active enzyme, is the only mannanase gene cloned which shows this domain structure.
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Affiliation(s)
- I K Cann
- Department of Animal Sciences, University of Illinois at Urbana-Champaign Urbana, IL 61801, USA
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King MR, Hendrickson DA, Southwood LL, Trumble TN, Johnson LW. Laparoscopic ovariectomy in two standing llamas. J Am Vet Med Assoc 1998; 213:523-5. [PMID: 9713537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Laparoscopic ovariectomy was performed in 2 llamas that were sedated but remained standing, avoiding possible complications associated with general anesthesia. All incisions were made in the left paralumbar fossa. The only intraoperative complications encountered were difficulty in maneuvering the laparoscope ventral to the uterine body in 1 llama because of distension of the urinary bladder, and a tendency to lean on the sidebar of the stocks in the other llama. The only postoperative complication was subcutaneous emphysema, which could be minimized by suctioning excess CO2 from the abdomen at completion of surgery. Laparoscopic ovariectomy was successful in these llamas and allowed direct examination and manipulation of the ovaries even though llamas were standing during surgery.
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Affiliation(s)
- M R King
- Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins 80523, USA
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Abstract
A gene encoding a thermostable alpha-galactosidase from the hyperthermophile Thermotoga neapolitana was cloned and sequenced. Sequence analysis showed that the 552-amino acid protein is similar to Escherichia coli Raf type alpha-galactosidase and belongs to Family 36 of the glycosyl hydrolases. Recombinant alpha-galactosidase expressed in E. coli has a molecular mass of ca. 61 kDa, and an optimum activity at 93 degrees C at pH 7.0. The enzyme is highly thermostable and retains 75% of activity after heating to 80 degrees C for 4 h. The potential application of the enzyme to high temperature processing of soy molasses has been demonstrated.
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Affiliation(s)
- M R King
- Food Science Department, University of Illinois, Urbana-Champaign 61801, USA
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Cox SM, King MR, Casey ML, MacDonald PC. Interleukin-1 beta, -1 alpha, and -6 and prostaglandins in vaginal/cervical fluids of pregnant women before and during labor. J Clin Endocrinol Metab 1993; 77:805-15. [PMID: 8370702 DOI: 10.1210/jcem.77.3.8370702] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Interleukin-1 beta (IL-1 beta) is not detected in the amniotic fluid of normal human pregnancies before the initiation of parturition, but during labor, both at term and preterm, this cytokine is present in the amniotic fluid of 25-40% of pregnancies. A critical question, however, is whether this finding is indicative of a role for IL-1 beta (directly or indirectly) in the initiation of parturition or is the result of IL-1 beta formation and entry into amniotic fluid as a natural sequela of normal labor. The forebag of the amniotic sac is formed during labor in response to cervical dilatation, and on the decidual surface, the tissues of this structure become exposed and bathed by vaginal fluids as the cervix opens. Microorganisms and bacterial toxins are present in vaginal fluid before labor begins; these agents should act upon the exposed tissues of the forebag to cause inflammation and evoke an inflammatory response. This study was conducted to examine the likelihood that the inflammatory mediators found in amniotic fluid in increased amounts at parturition are produced in forebag tissues after the onset of labor because of obliged inflammation in these tissues. Vaginal/cervical fluids were collected by lavage from nonpregnant women and from pregnant women at term before and during labor. The amount of immunoreactive IL-1 beta in vaginal/cervical fluids of pregnant women during labor (mean +/- SEM, 91.5 +/- 16.9 ng; n = 17) was significantly greater (P < 0.001) than that in fluids collected before labor (7.8 +/- 3 ng; n = 14). The in vivo rate of IL-1 beta secretion directly from the decidua lining the forebag during labor was brisk (1.71 +/- 0.88 ng/cm2.min; n = 4), consistent with previous observations of higher levels of pro-IL-1 beta mRNA in decidual tissues adherent to the forebag compared with those in decidua adherent to chorion laeve of the upper compartment of the amnionic sac. The vaginal fluid content of prostaglandins (PGs) during labor [PGE2, 82.1 +/- 16.4 ng; PGF2 alpha, 141.5 +/- 30.5 ng; PGFM, 35.2 +/- 5.8 ng (mean +/- SEM; n = 13)] was significantly greater for PGE2 and PGF2 alpha (P < 0.05 and 0.004, respectively) than that before labor (PGE2, 42.6 +/- 9.4 ng; PGF2 alpha, 35.3 +/- 8.5 ng; PGFM, 21.7 +/- 4.6 ng; n = 12). In addition, there was a significant increase in the ratio of PGF2 alpha to PGE2 (P < 0.03) in vaginal fluids during labor.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- S M Cox
- Cecil H. and Ida Green Center for Reproductive Biology Sciences, University of Texas Southwestern Medical Center, Dallas 75235-9051
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King MR. An automatic midstream urine collector. Nurs Times 1980; 76:1010-3. [PMID: 6901034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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King MR. Treatment of incontinence. Nurs Times 1980; 76:1006-10. [PMID: 6901033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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King MR. A study on incontinence in a psychiatric hospital. Nurs Times 1979; 75:1133-5. [PMID: 257420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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King MR, Manaster GJ. Body image, self-esteem, expectations, self-assessments, and actual success in a simulated job interview. J Appl Psychol 1977; 62:589-94. [PMID: 903339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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