1
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Kohl PA, Song C, Fletcher BJ, Best RL, Tchounwou C, Garcia Arceo X, Chung PJ, Miller HP, Wilson L, Choi MC, Li Y, Feinstein SC, Safinya CR. Complexes of tubulin oligomers and tau form a viscoelastic intervening network cross-bridging microtubules into bundles. Nat Commun 2024; 15:2362. [PMID: 38491006 PMCID: PMC10943092 DOI: 10.1038/s41467-024-46438-x] [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: 02/09/2023] [Accepted: 02/28/2024] [Indexed: 03/18/2024] Open
Abstract
The axon-initial-segment (AIS) of mature neurons contains microtubule (MT) fascicles (linear bundles) implicated as retrograde diffusion barriers in the retention of MT-associated protein (MAP) tau inside axons. Tau dysfunction and leakage outside of the axon is associated with neurodegeneration. We report on the structure of steady-state MT bundles in varying concentrations of Mg2+ or Ca2+ divalent cations in mixtures containing αβ-tubulin, full-length tau, and GTP at 37 °C in a physiological buffer. A concentration-time kinetic phase diagram generated by synchrotron SAXS reveals a wide-spacing MT bundle phase (Bws), a transient intermediate MT bundle phase (Bint), and a tubulin ring phase. SAXS with TEM of plastic-embedded samples provides evidence of a viscoelastic intervening network (IN) of complexes of tubulin oligomers and tau stabilizing MT bundles. In this model, αβ-tubulin oligomers in the IN are crosslinked by tau's MT binding repeats, which also link αβ-tubulin oligomers to αβ-tubulin within the MT lattice. The model challenges whether the cross-bridging of MTs is attributed entirely to MAPs. Tubulin-tau complexes in the IN or bound to isolated MTs are potential sites for enzymatic modification of tau, promoting nucleation and growth of tau fibrils in tauopathies.
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Affiliation(s)
- Phillip A Kohl
- Materials Research Laboratory, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Chaeyeon Song
- Materials Department, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Biomolecular Science and Engineering, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA
- Department of Physics, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Amorepacific R&I Center, Yongin, 17074, Republic of Korea
| | - Bretton J Fletcher
- Materials Department, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Biomolecular Science and Engineering, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA
- Department of Physics, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Rebecca L Best
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA
- Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Serimmune Inc., 150 Castilian Dr., Goleta, CA, 93117, USA
| | - Christine Tchounwou
- Materials Department, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Biomolecular Science and Engineering, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA
- Department of Physics, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Ximena Garcia Arceo
- Department of Physics, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Department of Chemistry and Biochemistry, University of California, San Diego, San Diego, CA, 93106, USA
| | - Peter J Chung
- Materials Department, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Biomolecular Science and Engineering, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA
- Department of Physics, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Department of Physics and Astronomy, University of Southern California, Los Angeles, CA, 90089, USA
| | - Herbert P Miller
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Leslie Wilson
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA
- Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Myung Chul Choi
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Daejeon, 34141, Korea
| | - Youli Li
- Materials Research Laboratory, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA.
| | - Stuart C Feinstein
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA
- Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Cyrus R Safinya
- Materials Department, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA.
- Biomolecular Science and Engineering, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA.
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA.
- Department of Physics, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA.
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Cho H, Lee J, Nho H, Lee K, Gim B, Lee J, Lee J, Ewert KK, Li Y, Feinstein SC, Safinya CR, Jin KS, Choi MC. Synchrotron X-ray study of intrinsically disordered and polyampholytic Tau 4RS and 4RL under controlled ionic strength. Eur Phys J E Soft Matter 2023; 46:73. [PMID: 37653246 DOI: 10.1140/epje/s10189-023-00328-0] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 07/25/2023] [Indexed: 09/02/2023]
Abstract
Aggregated and hyperphosphorylated Tau is one of the pathological hallmarks of Alzheimer's disease. Tau is a polyampholytic and intrinsically disordered protein (IDP). In this paper, we present for the first time experimental results on the ionic strength dependence of the radius of gyration (Rg) of human Tau 4RS and 4RL isoforms. Synchrotron X-ray scattering revealed that 4RS Rg is regulated from 65.4 to 58.5 Å and 4RL Rg is regulated from 70.9 to 57.9 Å by varying ionic strength from 0.01 to 0.592 M. The Rg of 4RL Tau is larger than 4RS at lower ionic strength. This result provides an insight into the ion-responsive nature of intrinsically disordered and polyampholytic Tau, and can be implicated to the further study of Tau-Tau and Tau-tubulin intermolecular structure in ionic environments.
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Affiliation(s)
- Hasaeam Cho
- Department of Bio and Brain Engineering, KAIST, Daejeon, 305-701, Korea
| | - Jimin Lee
- Department of Bio and Brain Engineering, KAIST, Daejeon, 305-701, Korea
| | - Hanjoon Nho
- Department of Bio and Brain Engineering, KAIST, Daejeon, 305-701, Korea
| | - Keunmin Lee
- Department of Bio and Brain Engineering, KAIST, Daejeon, 305-701, Korea
| | - Bopil Gim
- Department of Bio and Brain Engineering, KAIST, Daejeon, 305-701, Korea
| | - Juncheol Lee
- Department of Bio and Brain Engineering, KAIST, Daejeon, 305-701, Korea
| | - Jaehee Lee
- Department of Bio and Brain Engineering, KAIST, Daejeon, 305-701, Korea
| | - Kai K Ewert
- Materials Department, Molecular, Cellular, and Developmental Biology Department, Physics Department, and Biomolecular Science and Engineering Program, University of California, Santa Barbara, CA, 93106, USA
| | - Youli Li
- Materials Research Laboratory, University of California, Santa Barbara, CA, 93106, USA
| | - Stuart C Feinstein
- Molecular, Cellular, and Developmental Biology Department, College of Creative Studies Biology, Neuroscience Research Institute, University of California, Santa Barbara, CA, 93106, USA
| | - Cyrus R Safinya
- Materials Department, Molecular, Cellular, and Developmental Biology Department, Physics Department, and Biomolecular Science and Engineering Program, University of California, Santa Barbara, CA, 93106, USA
| | - Kyeong Sik Jin
- Pohang Accelerator Laboratory, POSTECH, Pohang, 37673, Korea
- Division of Advanced Nuclear Engineering, POSTECH, Pohang, 37673, Korea
| | - Myung Chul Choi
- Department of Bio and Brain Engineering, KAIST, Daejeon, 305-701, Korea.
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Aralis Z, Comer S, Ansorg H, Palmer C, Smith J, Feinstein SC, Fitzgibbons LN, Arias C. Efficient Tracing of the SARS-CoV-2 Omicron Variants in Santa Barbara County Using a Rapid Quantitative Reverse Transcription PCR Assay. Diagnostics (Basel) 2022; 12:2805. [PMID: 36428863 PMCID: PMC9689663 DOI: 10.3390/diagnostics12112805] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 11/01/2022] [Accepted: 11/03/2022] [Indexed: 11/18/2022] Open
Abstract
The emergence of the SARS-CoV-2 Omicron variant in 2021 is associated with a global surge of cases in late 2021 and early 2022. Identifying the introduction of novel SARS-CoV-2 variants to a population is imperative to inform decisions by clinicians and public health officials. Here, we describe a quantitative reverse transcription PCR-based assay (RT-qPCR) targeting unique mutations in the Omicron BA.1/BA1.1 and BA.2 viral genomes. This assay accurately and precisely detect the presence of these Omicron variants in patient samples in less than four hours. Using this assay, we tested 270 clinical samples and detected the introduction of Omicron BA.1/BA1.1 and BA.2 in the Santa Barbara County (SBC) population in December 2021 and February 2022, respectively. Identifying Omicron variants using this RT-qPCR assay showed complete concordance with whole viral genome sequencing; both assays indicated that Omicron was the dominant variant in SB County. Our data substantiate that RT-qPCR-based virus detection assays offer a fast and inexpensive alternative to NGS for virus variant-specific detection approach, which allows streamlining the detection of Omicron variants in patient samples.
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Affiliation(s)
- Zach Aralis
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
- Department of Biomolecular Science and Engineering, University of California, Santa Barbara, CA 93106, USA
| | - Stewart Comer
- Santa Barbara County Public Health Department, Santa Barbara, CA 93106, USA
- Department of Pathology, Santa Barbara Cottage Hospital, Santa Barbara, CA 93106, USA
- Pacific Diagnostic Laboratories, Santa Barbara, CA 93106, USA
| | - Henning Ansorg
- Santa Barbara County Public Health Department, Santa Barbara, CA 93106, USA
| | - Carl Palmer
- LegacyWorks Group, Santa Barbara, CA 93106, USA
| | - Jennifer Smith
- California NanoSystems Institute, University of California, Santa Barbara, CA 93106, USA
| | - Stuart C. Feinstein
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
- Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA
| | - Lynn N. Fitzgibbons
- Department of Medical Education, Division of Infectious Diseases, Santa Barbara Cottage Hospital, Santa Barbara, CA 93106, USA
| | - Carolina Arias
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
- Department of Biomolecular Science and Engineering, University of California, Santa Barbara, CA 93106, USA
- Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA
- Center for Stem Cell Biology and Engineering, University of California, Santa Barbara, CA 93106, USA
- Infectious Disease Initiative, Chan Zuckerberg BioHub, San Francisco, CA 93106, USA
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4
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Best RL, LaPointe NE, Azarenko O, Miller H, Genualdi C, Chih S, Shen BQ, Jordan MA, Wilson L, Feinstein SC, Stagg NJ. Microtubule and tubulin binding and regulation of microtubule dynamics by the antibody drug conjugate (ADC) payload, monomethyl auristatin E (MMAE): Mechanistic insights into MMAE ADC peripheral neuropathy. Toxicol Appl Pharmacol 2021; 421:115534. [PMID: 33852878 DOI: 10.1016/j.taap.2021.115534] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [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: 02/09/2021] [Revised: 04/09/2021] [Accepted: 04/09/2021] [Indexed: 11/25/2022]
Abstract
Monomethyl auristatin E (MMAE) is a potent anti-cancer microtubule-targeting agent (MTA) used as a payload in three approved MMAE-containing antibody drug conjugates (ADCs) and multiple ADCs in clinical development to treat different types of cancers. Unfortunately, MMAE-ADCs can induce peripheral neuropathy, a frequent adverse event leading to treatment dose reduction or discontinuation and subsequent clinical termination of many MMAE-ADCs. MMAE-ADC-induced peripheral neuropathy is attributed to non-specific uptake of the ADC in peripheral nerves and release of MMAE, disrupting microtubules (MTs) and causing neurodegeneration. However, molecular mechanisms underlying MMAE and MMAE-ADC effects on MTs remain unclear. Here, we characterized MMAE-tubulin/MT interactions in reconstituted in vitro soluble tubulin or MT systems and evaluated MMAE and vcMMAE-ADCs in cultured human MCF7 cells. MMAE bound to soluble tubulin heterodimers with a maximum stoichiometry of ~1:1, bound abundantly along the length of pre-assembled MTs and with high affinity at MT ends, introduced structural defects, suppressed MT dynamics, and reduced the kinetics and extent of MT assembly while promoting tubulin ring formation. In cells, MMAE and MMAE-ADC (via nonspecific uptake) suppressed proliferation, mitosis and MT dynamics, and disrupted the MT network. Comparing MMAE action to other MTAs supports the hypothesis that peripheral neuropathy severity is determined by the precise mechanism(s) of each individual drug-MT interaction (location of binding, affinity, effects on morphology and dynamics). This work demonstrates that MMAE binds extensively to tubulin and MTs and causes severe MT dysregulation, providing convincing evidence that MMAE-mediated inhibition of MT-dependent axonal transport leads to severe peripheral neuropathy.
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Affiliation(s)
- Rebecca L Best
- Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Nichole E LaPointe
- Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Olga Azarenko
- Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Herb Miller
- Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Christine Genualdi
- Safety Assessment, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Stephen Chih
- Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Ben-Quan Shen
- Preclinical and Translational PK, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Mary Ann Jordan
- Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Leslie Wilson
- Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Stuart C Feinstein
- Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA 93106, USA.
| | - Nicola J Stagg
- Safety Assessment, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA.
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5
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Fletcher B, Kohl PA, Song C, Tchounwou C, Chung PJ, Miller HP, Li Y, Chul Choi M, Wilson L, Feinstein SC, Safinya CR. Divalent Cations Induce Non-Equilibrium Phase Transitions in Tau-Mediated Microtubule Bundles Undergoing Dynamic Instability. Biophys J 2021. [DOI: 10.1016/j.bpj.2020.11.1650] [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: 11/27/2022] Open
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6
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Lee J, Song C, Lee J, Miller HP, Cho H, Gim B, Li Y, Feinstein SC, Wilson L, Safinya CR, Choi MC. Tubulin Double Helix: Lateral and Longitudinal Curvature Changes of Tubulin Protofilament. Small 2020; 16:e2001240. [PMID: 32794304 DOI: 10.1002/smll.202001240] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 07/14/2020] [Indexed: 06/11/2023]
Abstract
By virtue of their native structures, tubulin dimers are protein building blocks that are naturally preprogrammed to assemble into microtubules (MTs), which are cytoskeletal polymers. Here, polycation-directed (i.e., electrostatically tunable) assembly of tubulins is demonstrated by conformational changes to the tubulin protofilament in longitudinal and lateral directions, creating tubulin double helices and various tubular architectures. Synchrotron small-angle X-ray scattering and transmission electron microscopy reveal a remarkable range of nanoscale assembly structures: single- and double-layered double-helix tubulin tubules. The phase transitions from MTs to the new assemblies are dependent on the size and concentration of polycations. Two characteristic scales that determine the number of observed phases are the size of polycation compared to the size of tubulin (≈4 nm) and to MT diameter (≈25 nm). This work suggests the feasibility of using polycations that have scissor- and glue-like properties to achieve "programmable breakdown" of protein nanotubes, tearing MTs into double-stranded tubulins and building up previously undiscovered nanostructures. Importantly, a new role of tubulins is defined as 2D shape-controllable building blocks for supramolecular architectures. These findings provide insight into the design of protein-based functional materials, for example, as metallization templates for nanoscale electronic devices, molecular screws, and drug delivery vehicles.
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Affiliation(s)
- Juncheol Lee
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Daejeon, 34141, South Korea
| | - Chaeyeon Song
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Daejeon, 34141, South Korea
| | - Jimin Lee
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Daejeon, 34141, South Korea
| | - Herbert P Miller
- Molecular, Cellular and Developmental Biology Department and Neuroscience Research Institute, University of California, Santa Barbara, CA, 93106, USA
| | - Hasaeam Cho
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Daejeon, 34141, South Korea
| | - Bopil Gim
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Daejeon, 34141, South Korea
| | - Youli Li
- Materials Research Laboratory, University of California, Santa Barbara, CA, 93106, USA
| | - Stuart C Feinstein
- Molecular, Cellular and Developmental Biology Department and Neuroscience Research Institute, University of California, Santa Barbara, CA, 93106, USA
| | - Leslie Wilson
- Molecular, Cellular and Developmental Biology Department and Neuroscience Research Institute, University of California, Santa Barbara, CA, 93106, USA
| | - Cyrus R Safinya
- Materials, Physics, Molecular, Cellular and Developmental Biology Departments, University of California, Santa Barbara, CA, 93106, USA
| | - Myung Chul Choi
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Daejeon, 34141, South Korea
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Tchounwou C, Fletcher B, Best R, Wilson L, Feinstein SC, Safinya CR. Phase Separation Studies of Complexes of Intrinsically Disordered Protein Tau and Anionic Liposomes. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.3062] [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: 11/15/2022] Open
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8
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Kohl PA, Fletcher B, Song C, Chung PJ, Miller HP, Wilson L, Feinstein SC, Safinya CR. Structural Evolution of Energy-Consuming Tau Mediated Microtubule Bundles. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.3242] [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: 11/30/2022] Open
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9
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Fletcher B, Song C, Kohl PA, Miller HP, Li Y, Chul Choi M, Wilson L, Feinstein SC, Safinya CR. The Dependence of Tau-Mediated Microtubule Assembly and Bundle Formation on GTP and Mg2+. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.3241] [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: 10/25/2022] Open
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10
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Cho H, Nho H, Lee J, Yeop Lee S, Sik Jin K, Miller HP, Wilson L, Feinstein SC, Safinya CR, Chul Choi M. Microtubule in vitro Bundle Structures Depends on Tau Projection Domain and Ionic Strength. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.3237] [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: 10/25/2022] Open
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Safinya CR, Chung PJ, Song C, Li Y, Miller HP, Choi MC, Raviv U, Ewert KK, Wilson L, Feinstein SC. Minireview - Microtubules and Tubulin Oligomers: Shape Transitions and Assembly by Intrinsically Disordered Protein Tau and Cationic Biomolecules. Langmuir 2019; 35:15970-15978. [PMID: 31539262 PMCID: PMC6988848 DOI: 10.1021/acs.langmuir.9b02208] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
In this minireview, which is part of a special issue in honor of Jacob N. Israelachvili's remarkable research career on intermolecular forces and interfacial science, we present studies of structures, phase behavior, and forces in reaction mixtures of microtubules (MTs) and tubulin oligomers with either intrinsically disordered protein (IDP) Tau, cationic vesicles, or the polyamine spermine (4+). Bare MTs consist of 13 protofilaments (PFs), on average, where each PF is made of a linear stack of αβ-tubulin dimers (i.e., tubulin oligomers). We begin with a series of experiments which demonstrate the flexibility of PFs toward shape changes in response to local environmental cues. First, studies show that MT-associated protein (MAP) Tau controls the diameter of microtubules upon binding to the outer surface, implying a shape change in the cross-sectional area of PFs forming the MT perimeter. The diameter of a MT may also be controlled by the charge density of a lipid bilayer membrane that coats the outer surface. We further describe an experimental study where it is unexpectedly found that the biologically relevant polyamine spermine (+4e) is able to depolymerize taxol-stabilized microtubules with efficiency that increases with decreasing temperature. This MT destabilization drives a dynamical structural transition where inside-out curving of PFs, during the depolymerization peeling process, is followed by reassembly of ring-like curved PF building blocks into an array of helical inverted tubulin tubules. We finally turn to a very recent study on pressure-distance measurements in bundles of MTs employing the small-angle X-ray scattering (SAXS)-osmotic pressure technique, which complements the surface-forces-apparatus technique developed by Jacob N. Israelachvili. These latter studies are among the very few which are beginning to shed light on the precise nature of the interactions between MTs mediated by MAP Tau in 37 °C reaction mixtures containing GTP and lacking taxol.
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Affiliation(s)
- Cyrus R. Safinya
- Materials Department, Physics Department, Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, California 93106, USA
| | - Peter J. Chung
- James Franck Institute and Department of Chemistry, University of Chicago, Illinois 60637, USA
| | - Chaeyeon Song
- Amorepacific Corporation R&D Center, Yongin 17074, Republic of Korea
| | - Youli Li
- Materials Research Laboratory, University of California, Santa Barbara, California 93106, USA
| | - Herbert P. Miller
- Neuroscience Research Institute and Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, California 93106, USA
| | - Myung Chul Choi
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Republic of Korea
| | - Uri Raviv
- Institute of Chemistry and the Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 9190401, Israel
| | - Kai K. Ewert
- Materials Department, Physics Department, Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, California 93106, USA
| | - Leslie Wilson
- Neuroscience Research Institute and Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, California 93106, USA
| | - Stuart C. Feinstein
- Neuroscience Research Institute and Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, California 93106, USA
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Best RL, LaPointe NE, Liang J, Ruan K, Shade MF, Wilson L, Feinstein SC. Tau isoform-specific stabilization of intermediate states during microtubule assembly and disassembly. J Biol Chem 2019; 294:12265-12280. [PMID: 31266806 DOI: 10.1074/jbc.ra119.009124] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [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: 05/01/2019] [Revised: 06/24/2019] [Indexed: 01/27/2023] Open
Abstract
The microtubule (MT)-associated protein tau regulates the critical growing and shortening behaviors of MTs, and its normal activity is essential for neuronal development and maintenance. Accordingly, aberrant tau action is tightly associated with Alzheimer's disease and is genetically linked to several additional neurodegenerative diseases known as tauopathies. Although tau is known to promote net MT growth and stability, the precise mechanistic details governing its regulation of MT dynamics remain unclear. Here, we have used the slowly-hydrolyzable GTP analog, guanylyl-(α,β)-methylene-diphosphonate (GMPCPP), to examine the structural effects of tau at MT ends that may otherwise be too transient to observe. The addition of both four-repeat (4R) and three-repeat (3R) tau isoforms to pre-formed GMPCPP MTs resulted in the formation of extended, multiprotofilament-wide projections at MT ends. Furthermore, at temperatures too low for assembly of bona fide MTs, both tau isoforms promoted the formation of long spiral ribbons from GMPCPP tubulin heterodimers. In addition, GMPCPP MTs undergoing cold-induced disassembly in the presence of 4R tau (and to a much lesser extent 3R tau) also formed spirals. Finally, three pathological tau mutations known to cause neurodegeneration and dementia were differentially compromised in their abilities to stabilize MT disassembly intermediates. Taken together, we propose that tau promotes the formation/stabilization of intermediate states in MT assembly and disassembly by promoting both longitudinal and lateral tubulin-tubulin contacts. We hypothesize that these activities represent fundamental aspects of tau action that normally occur at the GTP-rich ends of GTP/GDP MTs and that may be compromised in neurodegeneration-causing tau variants.
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Affiliation(s)
- Rebecca L Best
- Neuroscience Research Institute and Department of Molecular, Cellular, and Developmental Biology, University of California Santa Barbara, Santa Barbara, California 93106
| | - Nichole E LaPointe
- Neuroscience Research Institute and Department of Molecular, Cellular, and Developmental Biology, University of California Santa Barbara, Santa Barbara, California 93106
| | - Jiahao Liang
- Neuroscience Research Institute and Department of Molecular, Cellular, and Developmental Biology, University of California Santa Barbara, Santa Barbara, California 93106
| | - Kevin Ruan
- Neuroscience Research Institute and Department of Molecular, Cellular, and Developmental Biology, University of California Santa Barbara, Santa Barbara, California 93106
| | - Madeleine F Shade
- Neuroscience Research Institute and Department of Molecular, Cellular, and Developmental Biology, University of California Santa Barbara, Santa Barbara, California 93106
| | - Leslie Wilson
- Neuroscience Research Institute and Department of Molecular, Cellular, and Developmental Biology, University of California Santa Barbara, Santa Barbara, California 93106
| | - Stuart C Feinstein
- Neuroscience Research Institute and Department of Molecular, Cellular, and Developmental Biology, University of California Santa Barbara, Santa Barbara, California 93106.
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13
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Tchounwou C, Fletcher B, Song C, Kohl PA, Chung PJ, Miller HP, Li Y, Choi MC, Wilson L, Feinstein SC, Safinya CR. The Effect of Site-Specific Acetylation Based Tau Mutations on Tau-Microtubule Associations. Biophys J 2019. [DOI: 10.1016/j.bpj.2018.11.1391] [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: 10/27/2022] Open
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14
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Cho H, Lee J, Lee J, Miller HP, Sik Jin K, Wilson L, Feinstein SC, Safinya CR, Chul Choi M. Higher Order Assembly Structures of Human Tau and Microtubules Regulated by Ionic Strength. Biophys J 2019. [DOI: 10.1016/j.bpj.2018.11.1390] [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: 10/27/2022] Open
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15
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Fletcher B, Song C, Kohl P, Chung PJ, Miller H, Li Y, Chul Choi M, Wilson L, Feinstein SC, Safinya CR. Condensation of Divalent Metail Ions by Map-Tau Remodels Tau-Microtubule Bundle Architecture. Biophys J 2019. [DOI: 10.1016/j.bpj.2018.11.1389] [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: 11/26/2022] Open
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16
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Cook BM, Wozniak KM, Proctor DA, Bromberg RB, Wu Y, Slusher BS, Littlefield BA, Jordan MA, Wilson L, Feinstein SC. Differential Morphological and Biochemical Recovery from Chemotherapy-Induced Peripheral Neuropathy Following Paclitaxel, Ixabepilone, or Eribulin Treatment in Mouse Sciatic Nerves. Neurotox Res 2018; 34:677-692. [PMID: 30051419 DOI: 10.1007/s12640-018-9929-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [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: 02/09/2018] [Revised: 06/15/2018] [Accepted: 06/20/2018] [Indexed: 12/29/2022]
Abstract
The reversibility of chemotherapy-induced peripheral neuropathy (CIPN), a disabling and potentially permanent side effect of microtubule-targeting agents (MTAs), is becoming an increasingly important issue as treatment outcomes improve. The molecular mechanisms regulating the variability in time to onset, severity, and time to recovery from CIPN between the common MTAs paclitaxel and eribulin are unknown. Previously (Benbow et al. in Neurotox Res 29:299-313, 2016), we found that after 2 weeks of a maximum tolerated dose (MTD) in mice, paclitaxel treatment resulted in severe reductions in axon area density, higher frequency of myelin abnormalities, and increased numbers of Schwann cell nuclei in sciatic nerves. Biochemically, eribulin induced greater microtubule-stabilizing effects than paclitaxel. Here, we extended these comparative MTD studies to assess the recovery from these short-term effects of paclitaxel, eribulin, and a third MTA, ixabepilone, over the course of 6 months. Paclitaxel induced a persistent reduction in axon area density over the entire 6-month recovery period, unlike ixabepilone- or eribulin-treated animals. The abundance of myelin abnormalities rapidly declined after cessation of all drugs but recovered most slowly after paclitaxel treatment. Paclitaxel- and ixabepilone- but not eribulin-treated animals exhibited increased Schwann cell numbers during the recovery period. Tubulin composition and biochemistry rapidly returned from MTD-induced levels of α-tubulin, acetylated α-tubulin, and end-binding protein 1 to control levels following cessation of drug treatment. Taken together, sciatic nerve axons recovered more rapidly from morphological effects in eribulin- and ixabepilone-treated animals than in paclitaxel-treated animals and drug-induced increases in protein expression levels following paclitaxel and eribulin treatment were relatively transient.
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Affiliation(s)
- B M Cook
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, CA, 93106, USA.,Department of Biomolecular Sciences and Engineering, University of California Santa Barbara, Santa Barbara, CA, 93016, USA
| | - K M Wozniak
- Johns Hopkins Drug Discovery, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - D A Proctor
- Department of Molecular, Cellular, and Developmental Biology, University of California Santa Barbara, Santa Barbara, CA, 93016, USA
| | - R B Bromberg
- Department of Molecular, Cellular, and Developmental Biology, University of California Santa Barbara, Santa Barbara, CA, 93016, USA
| | - Y Wu
- Johns Hopkins Drug Discovery, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - B S Slusher
- Johns Hopkins Drug Discovery, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - B A Littlefield
- Scientific Administration, Eisai Research Institute, Andover, MA, 01810, USA
| | - M A Jordan
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, CA, 93106, USA.,Department of Molecular, Cellular, and Developmental Biology, University of California Santa Barbara, Santa Barbara, CA, 93016, USA
| | - L Wilson
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, CA, 93106, USA.,Department of Molecular, Cellular, and Developmental Biology, University of California Santa Barbara, Santa Barbara, CA, 93016, USA
| | - Stuart C Feinstein
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, CA, 93106, USA. .,Department of Molecular, Cellular, and Developmental Biology, University of California Santa Barbara, Santa Barbara, CA, 93016, USA.
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17
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Chung PJ, Song C, Deek J, Miller HP, Li Y, Choi MC, Wilson L, Feinstein SC, Safinya CR. Comparison between 102k and 20k Poly(ethylene oxide) Depletants in Osmotic Pressure Measurements of Interfilament Forces in Cytoskeletal Systems. ACS Macro Lett 2018; 7:228-232. [PMID: 35610898 DOI: 10.1021/acsmacrolett.7b00937] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The proliferation of successful, cell-free reconstitutions of cytoskeletal networks have prompted measurements of forces between network elements via induced osmotic pressure by the addition of depletants. Indeed, it was through osmotic pressurization that Tau, an intrinsically disordered protein found in neuronal axons, was recently discovered to mediate two distinct microtubule (MT) bundle states, one widely spaced and a second tightly packed, separated by an energy barrier due to polyelectrolyte repulsions between opposing Tau projection domains on neighboring MT surfaces. Here, we compare interfilament force measurements in Tau coated MT bundles using PEO20k (poly(ethylene oxide), Mw = 20000), a commonly used inert depletant, and recently published measurements with PEO102k. While force measurements with either depletant reveals the transition between the two bundled states, measurements with PEO20k cannot recapitulate the correct critical pressure (Pc) at which widely spaced MT bundles transition to tightly packed MT bundles due to depletant penetration into widely spaced bundles below Pc. Surprisingly, upon transitioning to the tightly packed bundle state data from both depletants are in quantitative agreement indicative of expulsion of the smaller PEO20k depletant, but only at distances comparable or less than the PEO20k radius of gyration, significantly smaller than the effective diameter of PEO20k. While PEO102k (with size larger than the wall-to-wall distance between MTs in bundles) can more accurately capture the force response behavior at low to intermediate pressures (<104 Pa), measurements with PEO20k, beyond the overlap regime with PEO102k, extend the achievable osmotic pressure range into the higher-pressure regime (∼5 × 104 Pa). The data underscores the importance of the use of polymeric depletants of different sizes to elucidate force response behavior of cytoskeletal filamentous networks over a more complete extended pressure range.
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Affiliation(s)
| | | | | | | | | | - Myung Chul Choi
- Department
of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Republic of Korea
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18
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Wozniak KM, Vornov JJ, Wu Y, Liu Y, Carozzi VA, Rodriguez-Menendez V, Ballarini E, Alberti P, Pozzi E, Semperboni S, Cook BM, Littlefield BA, Nomoto K, Condon K, Eckley S, DesJardins C, Wilson L, Jordan MA, Feinstein SC, Cavaletti G, Polydefkis M, Slusher BS. Peripheral Neuropathy Induced by Microtubule-Targeted Chemotherapies: Insights into Acute Injury and Long-term Recovery. Cancer Res 2017; 78:817-829. [PMID: 29191802 DOI: 10.1158/0008-5472.can-17-1467] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 08/30/2017] [Accepted: 11/21/2017] [Indexed: 01/01/2023]
Abstract
Chemotherapy-induced peripheral neuropathy (CIPN) is a major cause of disability in cancer survivors. CIPN investigations in preclinical model systems have focused on either behaviors or acute changes in nerve conduction velocity (NCV) and amplitude, but greater understanding of the underlying nature of axonal injury and its long-term processes is needed as cancer patients live longer. In this study, we used multiple independent endpoints to systematically characterize CIPN recovery in mice exposed to the antitubulin cancer drugs eribulin, ixabepilone, paclitaxel, or vinorelbine at MTDs. All of the drugs ablated intraepidermal nerve fibers and produced axonopathy, with a secondary disruption in myelin structure within 2 weeks of drug administration. In addition, all of the drugs reduced sensory NCV and amplitude, with greater deficits after paclitaxel and lesser deficits after ixabepilone. These effects correlated with degeneration in dorsal root ganglia (DRG) and sciatic nerve and abundance of Schwann cells. Although most injuries were fully reversible after 3-6 months after administration of eribulin, vinorelbine, and ixabepilone, we observed delayed recovery after paclitaxel that produced a more severe, pervasive, and prolonged neurotoxicity. Compared with other agents, paclitaxel also displayed a unique prolonged exposure in sciatic nerve and DRG. The most sensitive indicator of toxicity was axonopathy and secondary myelin changes accompanied by a reduction in intraepidermal nerve fiber density. Taken together, our findings suggest that intraepidermal nerve fiber density and changes in NCV and amplitude might provide measures of axonal injury to guide clinical practice.Significance: This detailed preclinical study of the long-term effects of widely used antitubulin cancer drugs on the peripheral nervous system may help guide clinical evaluations to improve personalized care in limiting neurotoxicity in cancer survivors. Cancer Res; 78(3); 817-29. ©2017 AACR.
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Affiliation(s)
- Krystyna M Wozniak
- Johns Hopkins Drug Discovery, Johns Hopkins School of Medicine, Baltimore, Maryland
| | | | - Ying Wu
- Johns Hopkins Drug Discovery, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Ying Liu
- Department of Neurology and the Cutaneous Nerve Laboratory, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Valentina A Carozzi
- Experimental Neurology Unit and PhD program in Neuroscience, School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy
| | - Virginia Rodriguez-Menendez
- Experimental Neurology Unit and PhD program in Neuroscience, School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy
| | - Elisa Ballarini
- Experimental Neurology Unit and PhD program in Neuroscience, School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy
| | - Paola Alberti
- Experimental Neurology Unit and PhD program in Neuroscience, School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy
| | - Eleonora Pozzi
- Experimental Neurology Unit and PhD program in Neuroscience, School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy
| | - Sara Semperboni
- Experimental Neurology Unit and PhD program in Neuroscience, School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy
| | - Brett M Cook
- Neurosci Research Institute, University of California, Santa Barbara, California.,Biomolecular Science and Engineering Program, University of California, Santa Barbara, California
| | | | | | | | | | | | - Leslie Wilson
- Neurosci Research Institute, University of California, Santa Barbara, California.,Biomolecular Science and Engineering Program, University of California, Santa Barbara, California.,Department of Molecular Cellular and Developmental Biology, University of California, Santa Barbara, California
| | - Mary A Jordan
- Neurosci Research Institute, University of California, Santa Barbara, California.,Department of Molecular Cellular and Developmental Biology, University of California, Santa Barbara, California
| | - Stuart C Feinstein
- Neurosci Research Institute, University of California, Santa Barbara, California.,Department of Molecular Cellular and Developmental Biology, University of California, Santa Barbara, California
| | - Guido Cavaletti
- Experimental Neurology Unit and PhD program in Neuroscience, School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy
| | - Michael Polydefkis
- Department of Neurology and the Cutaneous Nerve Laboratory, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Barbara S Slusher
- Johns Hopkins Drug Discovery and Departments of Neurology, Psychiatry, Neuroscience, Medicine and Oncology, Johns Hopkins School of Medicine, Baltimore, Maryland.
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19
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de Almeida NEC, Do TD, LaPointe NE, Tro M, Feinstein SC, Shea JE, Bowers MT. 1,2,3,4,6-penta-O-galloyl-β-D-glucopyranose Binds to the N-terminal Metal Binding Region to Inhibit Amyloid β-protein Oligomer and Fibril Formation. Int J Mass Spectrom 2017; 420:24-34. [PMID: 29056865 PMCID: PMC5644501 DOI: 10.1016/j.ijms.2016.09.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The early oligomerization of amyloid β-protein (Aβ) is a crucial step in the etiology of Alzheimer's disease (AD), in which soluble and highly neurotoxic oligomers are produced and accumulated inside neurons. In search of therapeutic solutions for AD treatment and prevention, potent inhibitors that remodel Aβ assembly and prevent neurotoxic oligomer formation offer a promising approach. In particular, several polyphenolic compounds have shown anti-aggregation properties and good efficacy on inhibiting oligomeric amyloid formation. 1,2,3,4,6-penta-O-galloyl-β-D-glucopyranose is a large polyphenol that has been shown to be effective at inhibiting aggregation of full-length Aβ1-40 and Aβ1-42, but has the opposite effect on the C-terminal fragment Aβ25-35. Here, we use a combination of ion mobility coupled to mass spectrometry (IMS-MS), transmission electron microscopy (TEM) and molecular dynamics (MD) simulations to elucidate the inhibitory effect of PGG on aggregation of full-length Aβ1-40 and Aβ1-42. We show that PGG interacts strongly with these two peptides, especially in their N-terminal metal binding regions, and suppresses the formation of Aβ1-40 tetramer and Aβ1-42 dodecamer. By exploring multiple facets of polyphenol-amyloid interactions, we provide a molecular basis for the opposing effects of PGG on full-length Aβ and its C-terminal fragments.
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Affiliation(s)
- Natália E. C. de Almeida
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
| | - Thanh D. Do
- Department of Chemistry and the Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Nichole E. LaPointe
- Neuroscience Research Institute and Department of Molecular Cellular and Developmental Biology, University of California, Santa Barbara, California 93106, United States
| | - Michael Tro
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
| | - Stuart C. Feinstein
- Neuroscience Research Institute and Department of Molecular Cellular and Developmental Biology, University of California, Santa Barbara, California 93106, United States
| | - Joan-Emma Shea
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
| | - Michael T. Bowers
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
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20
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Benbow SJ, Wozniak KM, Kulesh B, Savage A, Slusher BS, Littlefield BA, Jordan MA, Wilson L, Feinstein SC. Microtubule-Targeting Agents Eribulin and Paclitaxel Differentially Affect Neuronal Cell Bodies in Chemotherapy-Induced Peripheral Neuropathy. Neurotox Res 2017; 32:151-162. [PMID: 28391556 DOI: 10.1007/s12640-017-9729-6] [Citation(s) in RCA: 14] [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: 11/08/2016] [Revised: 03/21/2017] [Accepted: 03/27/2017] [Indexed: 01/05/2023]
Abstract
Chemotherapy-induced peripheral neuropathy (CIPN) is a common side effect of anticancer treatment with microtubule-targeted agents (MTAs). The frequency of severe CIPN, which can be dose limiting and even life threatening, varies widely among different MTAs. For example, paclitaxel induces a higher frequency of severe CIPN than does eribulin. Different MTAs also possess distinct mechanisms of microtubule-targeted action. Recently, we demonstrated that paclitaxel and eribulin differentially affect sciatic nerve axons, with paclitaxel inducing more pronounced neurodegenerative effects and eribulin inducing greater microtubule stabilizing biochemical effects. Here, we complement and extend these axonal studies by assessing the effects of paclitaxel and eribulin in the cell bodies of sciatic nerve axons, housed in the dorsal root ganglia (DRG). Importantly, the microtubule network in cell bodies is known to be significantly more dynamic than in axons. Paclitaxel induced activating transcription factor 3 expression, a marker of neuronal stress/injury. Paclitaxel also increased expression levels of acetylated tubulin and end binding protein 1, markers of microtubule stability and growth, respectively. These effects are hypothesized to be detrimental to the dynamic microtubule network within the cell bodies. In contrast, eribulin had no significant effect on any of these parameters in the cell bodies. Taken together, DRG cell bodies and their axons, two distinct neuronal cell compartments, contain functionally distinct microtubule networks that exhibit unique biochemical responses to different MTA treatments. We hypothesize that these distinct mechanistic actions may underlie the variability seen in the initiation, progression, persistence, and recovery from CIPN.
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Affiliation(s)
- Sarah J Benbow
- Neuroscience Research Institute, University of California, Santa Barbara, CA, 93106, USA.,Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA, USA
| | - Krystyna M Wozniak
- Johns Hopkins Drug Discovery Program, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Bridget Kulesh
- Neuroscience Research Institute, University of California, Santa Barbara, CA, 93106, USA.,Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA, USA
| | - April Savage
- Neuroscience Research Institute, University of California, Santa Barbara, CA, 93106, USA.,Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA, USA
| | - Barbara S Slusher
- Johns Hopkins Drug Discovery Program, Johns Hopkins School of Medicine, Baltimore, MD, USA.,Departments of Neurology, Psychiatry, Neuroscience, Medicine and Oncology, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | | | - Mary Ann Jordan
- Neuroscience Research Institute, University of California, Santa Barbara, CA, 93106, USA.,Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA, USA
| | - Leslie Wilson
- Neuroscience Research Institute, University of California, Santa Barbara, CA, 93106, USA.,Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA, USA
| | - Stuart C Feinstein
- Neuroscience Research Institute, University of California, Santa Barbara, CA, 93106, USA. .,Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA, USA.
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21
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Chung PJ, Song C, Deek J, Miller HP, Li Y, Chul Choi M, Wilson L, Feinstein SC, Safinya CR. Cell-Free Reconstituions of Tau and Tubulin Mediate Complex Microtubule Architectures Found in the Axon. Biophys J 2017. [DOI: 10.1016/j.bpj.2016.11.3038] [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: 11/16/2022] Open
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22
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Choi MC, Chung PJ, Song C, Miller HP, Kiris E, Li Y, Wilson L, Feinstein SC, Safinya CR. Paclitaxel suppresses Tau-mediated microtubule bundling in a concentration-dependent manner. Biochim Biophys Acta Gen Subj 2016; 1861:3456-3463. [PMID: 27632200 DOI: 10.1016/j.bbagen.2016.09.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [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: 02/07/2016] [Revised: 08/31/2016] [Accepted: 09/09/2016] [Indexed: 10/21/2022]
Abstract
BACKGROUND Microtubules (MTs) are protein nanotubes comprised of straight protofilaments (PFs), head to tail assemblies of αβ-tubulin heterodimers. Previously, it was shown that Tau, a microtubule-associated protein (MAP) localized to neuronal axons, regulates the average number of PFs in microtubules with increasing inner radius <RinMT> observed for increasing Tau/tubulin-dimer molar ratio ΦTau at paclitaxel/tubulin-dimer molar ratio ΛPtxl=1/1. METHODS We report a synchrotron SAXS and TEM study of the phase behavior of microtubules as a function of varying concentrations of paclitaxel (1/32≤ΛPtxl≤1/4) and Tau (human isoform 3RS, 0≤Φ3RS≤1/2) at room temperature. RESULTS Tau and paclitaxel have opposing regulatory effects on microtubule bundling architectures and microtubule diameter. Surprisingly and in contrast to previous results at ΛPtxl=1/1 where microtubule bundles are absent, in the lower paclitaxel concentration regime (ΛPtxl≤1/4), we observe both microtubule doublets and triplets with increasing Tau. Furthermore, increasing paclitaxel concentration (up to ΛPtxl=1/1) slightly decreased the average microtubule diameter (by ~1 PF) while increasing Tau concentration (up to Φ3RS=1/2) significantly increased the diameter (by ~2-3 PFs). CONCLUSIONS The suppression of Tau-mediated microtubule bundling with increasing paclitaxel is consistent with paclitaxel seeding more, but shorter, microtubules by rapidly exhausting tubulin available for polymerization. Microtubule bundles require the aggregate Tau-Tau attractions along the microtubule length to overcome individual microtubule thermal energies disrupting bundles. GENERAL SIGNIFICANCE Investigating MAP-mediated interactions between microtubules (as it relates to in vivo behavior) requires the elimination or minimization of paclitaxel.
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Affiliation(s)
- Myung Chul Choi
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Republic of Korea
| | - Peter J Chung
- Materials Department, Physics Department, Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, California 93106, USA
| | - Chaeyeon Song
- Materials Department, Physics Department, Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, California 93106, USA
| | - Herbert P Miller
- Neuroscience Research Institute and Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, California 93106, USA
| | - E Kiris
- Neuroscience Research Institute and Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, California 93106, USA
| | - Youli Li
- Materials Research Laboratory, University of California, Santa Barbara, California 93106, USA
| | - Leslie Wilson
- Neuroscience Research Institute and Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, California 93106, USA
| | - Stuart C Feinstein
- Neuroscience Research Institute and Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, California 93106, USA
| | - Cyrus R Safinya
- Materials Department, Physics Department, Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, California 93106, USA.
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23
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Feinstein HE, Benbow SJ, LaPointe NE, Patel N, Ramachandran S, Do TD, Gaylord MR, Huskey NE, Dressler N, Korff M, Quon B, Cantrell KL, Bowers MT, Lal R, Feinstein SC. Oligomerization of the microtubule-associated protein tau is mediated by its N-terminal sequences: implications for normal and pathological tau action. J Neurochem 2016; 137:939-54. [PMID: 26953146 PMCID: PMC4899250 DOI: 10.1111/jnc.13604] [Citation(s) in RCA: 26] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 02/10/2016] [Accepted: 03/06/2016] [Indexed: 11/28/2022]
Abstract
Despite extensive structure-function analyses, the molecular mechanisms of normal and pathological tau action remain poorly understood. How does the C-terminal microtubule-binding region regulate microtubule dynamics and bundling? In what biophysical form does tau transfer trans-synaptically from one neuron to another, promoting neurodegeneration and dementia? Previous biochemical/biophysical work led to the hypothesis that tau can dimerize via electrostatic interactions between two N-terminal 'projection domains' aligned in an anti-parallel fashion, generating a multivalent complex capable of interacting with multiple tubulin subunits. We sought to test this dimerization model directly. Native gel analyses of full-length tau and deletion constructs demonstrate that the N-terminal region leads to multiple bands, consistent with oligomerization. Ferguson analyses of native gels indicate that an N-terminal fragment (tau(45-230) ) assembles into heptamers/octamers. Ferguson analyses of denaturing gels demonstrates that tau(45-230) can dimerize even in sodium dodecyl sulfate. Atomic force microscopy reveals multiple levels of oligomerization by both full-length tau and tau(45-230) . Finally, ion mobility-mass spectrometric analyses of tau(106-144) , a small peptide containing the core of the hypothesized dimerization region, also demonstrate oligomerization. Thus, multiple independent strategies demonstrate that the N-terminal region of tau can mediate higher order oligomerization, which may have important implications for both normal and pathological tau action. The microtubule-associated protein tau is essential for neuronal development and maintenance, but is also central to Alzheimer's and related dementias. Unfortunately, the molecular mechanisms underlying normal and pathological tau action remain poorly understood. Here, we demonstrate that tau can homo-oligomerize, providing novel mechanistic models for normal tau action (promoting microtubule growth and bundling, suppressing microtubule shortening) and pathological tau action (poisoning of oligomeric complexes).
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Affiliation(s)
- H Eric Feinstein
- Neuroscience Research Institute, University of California, Santa Barbara, California, USA
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, California, USA
| | - Sarah J Benbow
- Neuroscience Research Institute, University of California, Santa Barbara, California, USA
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, California, USA
| | - Nichole E LaPointe
- Neuroscience Research Institute, University of California, Santa Barbara, California, USA
| | - Nirav Patel
- Department of Bioengineering, Department of Mechanical Engineering and Materials Science Graduate Program, University of California, San Diego, California, USA
| | - Srinivasan Ramachandran
- Department of Bioengineering, Department of Mechanical Engineering and Materials Science Graduate Program, University of California, San Diego, California, USA
| | - Thanh D Do
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California, USA
| | - Michelle R Gaylord
- Neuroscience Research Institute, University of California, Santa Barbara, California, USA
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, California, USA
| | - Noelle E Huskey
- Neuroscience Research Institute, University of California, Santa Barbara, California, USA
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, California, USA
| | - Nicolette Dressler
- Department of Chemistry, Westmont College, Santa Barbara, California, USA
| | - Megan Korff
- Department of Chemistry, Westmont College, Santa Barbara, California, USA
| | - Brady Quon
- Department of Chemistry, Westmont College, Santa Barbara, California, USA
| | | | - Michael T Bowers
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California, USA
| | - Ratnesh Lal
- Department of Bioengineering, Department of Mechanical Engineering and Materials Science Graduate Program, University of California, San Diego, California, USA
| | - Stuart C Feinstein
- Neuroscience Research Institute, University of California, Santa Barbara, California, USA
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, California, USA
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24
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de Almeida NEC, Do TD, Tro M, LaPointe NE, Feinstein SC, Shea JE, Bowers MT. Opposing Effects of Cucurbit[7]uril and 1,2,3,4,6-Penta-O-galloyl-β-d-glucopyranose on Amyloid β25-35 Assembly. ACS Chem Neurosci 2016; 7:218-26. [PMID: 26629788 PMCID: PMC4758880 DOI: 10.1021/acschemneuro.5b00280] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [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] [Indexed: 11/30/2022] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease characterized by extracellular deposits of amyloid β protein (Aβ) in the brain. The conversion of soluble monomers to amyloid Aβ fibrils is a complicated process and involves several transient oligomeric species, which are widely believed to be highly toxic and play a crucial role in the etiology of AD. The development of inhibitors to prevent formation of small and midsized oligomers is a promising strategy for AD treatment. In this work, we employ ion mobility spectrometry (IMS), transmission electron microscopy (TEM), and molecular dynamics (MD) simulations to elucidate the structural modulation promoted by two potential inhibitors of Aβ oligomerization, cucurbit[7]uril (CB[7]) and 1,2,3,4,6-penta-O-galloyl-β-d-glucopyranose (PGG), on early oligomer and fibril formation of the Aβ25-35 fragment. One and two CB[7] molecules bind to Aβ25-35 monomers and dimers, respectively, and suppress aggregation by remodeling early oligomer structures and inhibiting the formation of higher-order oligomers. On the other hand, nonselective binding was observed between PGG and Aβ25-35. The interactions between PGG and Aβ25-35, surprisingly, enhanced the formation of Aβ aggregates by promoting extended Aβ25-35 conformations in both homo- and hetero-oligomers. When both ligands were present, the inhibitory effect of CB[7] overrode the stimulatory effect of PGG on Aβ25-35 aggregation, suppressing the formation of large amyloid oligomers and eliminating the structural conversion from isotropic to β-rich topologies induced by PGG. Our results provide mechanistic insights into CB[7] and PGG action on Aβ oligomerization. They also demonstrate the power of the IMS technique to investigate mechanisms of multiple small-molecule agents on the amyloid formation process.
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Affiliation(s)
- Natália E. C. de Almeida
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
| | - Thanh D. Do
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
| | - Michael Tro
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
| | - Nichole E. LaPointe
- Neuroscience Research Institute and Department of Molecular Cellular and Developmental Biology, University of California, Santa Barbara, California 93106, United States
| | - Stuart C. Feinstein
- Neuroscience Research Institute and Department of Molecular Cellular and Developmental Biology, University of California, Santa Barbara, California 93106, United States
| | - Joan-Emma Shea
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
| | - Michael T. Bowers
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
- Corresponding author: Michael T. Bowers. Tel: +1-805-893-2673;
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Song C, Chung P, Miller HP, Li Y, Feinstein SC, Wilson L, Safinya CR. The Effect of Multivalent Cations on Microtubule-Protein Tau Ordering. Biophys J 2016. [DOI: 10.1016/j.bpj.2015.11.1912] [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: 11/30/2022] Open
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26
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Chung PJ, Song C, Deek J, Miller HP, Li Y, Wilson L, Feinstein SC, Safinya CR. Tau Mediates Widely-Spaced Microtubule Bundles through Local Polyion Attractions at the Midplane Layer: A Novel, Functional Mechanism for Intrinsically Disordered Proteins. Biophys J 2016. [DOI: 10.1016/j.bpj.2015.11.2958] [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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27
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Do TD, LaPointe NE, Nelson R, Krotee P, Hayden EY, Ulrich B, Quan S, Feinstein SC, Teplow DB, Eisenberg D, Shea JE, Bowers MT. Amyloid β-Protein C-Terminal Fragments: Formation of Cylindrins and β-Barrels. J Am Chem Soc 2016; 138:549-57. [PMID: 26700445 DOI: 10.1021/jacs.5b09536] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
In order to evaluate potential therapeutic targets for treatment of amyloidoses such as Alzheimer's disease (AD), it is essential to determine the structures of toxic amyloid oligomers. However, for the amyloid β-protein peptide (Aβ), thought to be the seminal neuropathogenetic agent in AD, its fast aggregation kinetics and the rapid equilibrium dynamics among oligomers of different size pose significant experimental challenges. Here we use ion-mobility mass spectrometry, in combination with electron microscopy, atomic force microscopy, and computational modeling, to test the hypothesis that Aβ peptides can form oligomeric structures resembling cylindrins and β-barrels. These structures are hypothesized to cause neuronal injury and death through perturbation of plasma membrane integrity. We show that hexamers of C-terminal Aβ fragments, including Aβ(24-34), Aβ(25-35) and Aβ(26-36), have collision cross sections similar to those of cylindrins. We also show that linking two identical fragments head-to-tail using diglycine increases the proportion of cylindrin-sized oligomers. In addition, we find that larger oligomers of these fragments may adopt β-barrel structures and that β-barrels can be formed by folding an out-of-register β-sheet, a common type of structure found in amyloid proteins.
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Affiliation(s)
- Thanh D Do
- Department of Chemistry and Biochemistry and ‡Department of Physics, ¶Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California , Santa Barbara, California 93106, United States.,Departments of Chemistry and Biochemistry and Biological Chemistry, Howard Hughes Medical Institute, UCLA-DOE Institute for Genomics and Proteomics, and ∥Department of Neurology, David Geffen School of Medicine at UCLA, ∇Mary S. Easton Center for Alzheimer's Disease Research at UCLA, and Brain Research Institute and Molecular Biology Institute, University of California , 635 Charles Young Drive South, Los Angeles, California 90095, United States
| | - Nichole E LaPointe
- Department of Chemistry and Biochemistry and ‡Department of Physics, ¶Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California , Santa Barbara, California 93106, United States.,Departments of Chemistry and Biochemistry and Biological Chemistry, Howard Hughes Medical Institute, UCLA-DOE Institute for Genomics and Proteomics, and ∥Department of Neurology, David Geffen School of Medicine at UCLA, ∇Mary S. Easton Center for Alzheimer's Disease Research at UCLA, and Brain Research Institute and Molecular Biology Institute, University of California , 635 Charles Young Drive South, Los Angeles, California 90095, United States
| | - Rebecca Nelson
- Department of Chemistry and Biochemistry and ‡Department of Physics, ¶Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California , Santa Barbara, California 93106, United States.,Departments of Chemistry and Biochemistry and Biological Chemistry, Howard Hughes Medical Institute, UCLA-DOE Institute for Genomics and Proteomics, and ∥Department of Neurology, David Geffen School of Medicine at UCLA, ∇Mary S. Easton Center for Alzheimer's Disease Research at UCLA, and Brain Research Institute and Molecular Biology Institute, University of California , 635 Charles Young Drive South, Los Angeles, California 90095, United States
| | - Pascal Krotee
- Department of Chemistry and Biochemistry and ‡Department of Physics, ¶Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California , Santa Barbara, California 93106, United States.,Departments of Chemistry and Biochemistry and Biological Chemistry, Howard Hughes Medical Institute, UCLA-DOE Institute for Genomics and Proteomics, and ∥Department of Neurology, David Geffen School of Medicine at UCLA, ∇Mary S. Easton Center for Alzheimer's Disease Research at UCLA, and Brain Research Institute and Molecular Biology Institute, University of California , 635 Charles Young Drive South, Los Angeles, California 90095, United States
| | - Eric Y Hayden
- Department of Chemistry and Biochemistry and ‡Department of Physics, ¶Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California , Santa Barbara, California 93106, United States.,Departments of Chemistry and Biochemistry and Biological Chemistry, Howard Hughes Medical Institute, UCLA-DOE Institute for Genomics and Proteomics, and ∥Department of Neurology, David Geffen School of Medicine at UCLA, ∇Mary S. Easton Center for Alzheimer's Disease Research at UCLA, and Brain Research Institute and Molecular Biology Institute, University of California , 635 Charles Young Drive South, Los Angeles, California 90095, United States
| | - Brittany Ulrich
- Department of Chemistry and Biochemistry and ‡Department of Physics, ¶Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California , Santa Barbara, California 93106, United States.,Departments of Chemistry and Biochemistry and Biological Chemistry, Howard Hughes Medical Institute, UCLA-DOE Institute for Genomics and Proteomics, and ∥Department of Neurology, David Geffen School of Medicine at UCLA, ∇Mary S. Easton Center for Alzheimer's Disease Research at UCLA, and Brain Research Institute and Molecular Biology Institute, University of California , 635 Charles Young Drive South, Los Angeles, California 90095, United States
| | - Sarah Quan
- Department of Chemistry and Biochemistry and ‡Department of Physics, ¶Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California , Santa Barbara, California 93106, United States.,Departments of Chemistry and Biochemistry and Biological Chemistry, Howard Hughes Medical Institute, UCLA-DOE Institute for Genomics and Proteomics, and ∥Department of Neurology, David Geffen School of Medicine at UCLA, ∇Mary S. Easton Center for Alzheimer's Disease Research at UCLA, and Brain Research Institute and Molecular Biology Institute, University of California , 635 Charles Young Drive South, Los Angeles, California 90095, United States
| | - Stuart C Feinstein
- Department of Chemistry and Biochemistry and ‡Department of Physics, ¶Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California , Santa Barbara, California 93106, United States.,Departments of Chemistry and Biochemistry and Biological Chemistry, Howard Hughes Medical Institute, UCLA-DOE Institute for Genomics and Proteomics, and ∥Department of Neurology, David Geffen School of Medicine at UCLA, ∇Mary S. Easton Center for Alzheimer's Disease Research at UCLA, and Brain Research Institute and Molecular Biology Institute, University of California , 635 Charles Young Drive South, Los Angeles, California 90095, United States
| | - David B Teplow
- Department of Chemistry and Biochemistry and ‡Department of Physics, ¶Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California , Santa Barbara, California 93106, United States.,Departments of Chemistry and Biochemistry and Biological Chemistry, Howard Hughes Medical Institute, UCLA-DOE Institute for Genomics and Proteomics, and ∥Department of Neurology, David Geffen School of Medicine at UCLA, ∇Mary S. Easton Center for Alzheimer's Disease Research at UCLA, and Brain Research Institute and Molecular Biology Institute, University of California , 635 Charles Young Drive South, Los Angeles, California 90095, United States
| | - David Eisenberg
- Department of Chemistry and Biochemistry and ‡Department of Physics, ¶Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California , Santa Barbara, California 93106, United States.,Departments of Chemistry and Biochemistry and Biological Chemistry, Howard Hughes Medical Institute, UCLA-DOE Institute for Genomics and Proteomics, and ∥Department of Neurology, David Geffen School of Medicine at UCLA, ∇Mary S. Easton Center for Alzheimer's Disease Research at UCLA, and Brain Research Institute and Molecular Biology Institute, University of California , 635 Charles Young Drive South, Los Angeles, California 90095, United States
| | - Joan-Emma Shea
- Department of Chemistry and Biochemistry and ‡Department of Physics, ¶Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California , Santa Barbara, California 93106, United States.,Departments of Chemistry and Biochemistry and Biological Chemistry, Howard Hughes Medical Institute, UCLA-DOE Institute for Genomics and Proteomics, and ∥Department of Neurology, David Geffen School of Medicine at UCLA, ∇Mary S. Easton Center for Alzheimer's Disease Research at UCLA, and Brain Research Institute and Molecular Biology Institute, University of California , 635 Charles Young Drive South, Los Angeles, California 90095, United States
| | - Michael T Bowers
- Department of Chemistry and Biochemistry and ‡Department of Physics, ¶Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California , Santa Barbara, California 93106, United States.,Departments of Chemistry and Biochemistry and Biological Chemistry, Howard Hughes Medical Institute, UCLA-DOE Institute for Genomics and Proteomics, and ∥Department of Neurology, David Geffen School of Medicine at UCLA, ∇Mary S. Easton Center for Alzheimer's Disease Research at UCLA, and Brain Research Institute and Molecular Biology Institute, University of California , 635 Charles Young Drive South, Los Angeles, California 90095, United States
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Do TD, de Almeida NEC, LaPointe NE, Chamas A, Feinstein SC, Bowers MT. Amino Acid Metaclusters: Implications of Growth Trends on Peptide Self-Assembly and Structure. Anal Chem 2015; 88:868-76. [PMID: 26632663 DOI: 10.1021/acs.analchem.5b03454] [Citation(s) in RCA: 34] [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] [Indexed: 11/30/2022]
Abstract
Ion-mobility mass spectrometry is utilized to examine the metacluster formation of serine, asparagine, isoleucine, and tryptophan. These amino acids are representative of different classes of noncharged amino acids. We show that they can form relatively large metaclusters in solution that are difficult or impossible to observe by traditional solution techniques. We further demonstrate, as an example, that the formation of Ser metaclusters is not an ESI artifact because large metaclusters can be detected in negative polarity and low concentration with similar cross sections to those measured in positive polarity and higher concentration. The growth trends of tryptophan and isoleucine metaclusters, along with serine, asparagine, and the previously studied phenylalanine, are balanced among various intrinsic properties of individual amino acids (e.g., hydrophobicity, size, and shape). The metacluster cross sections of hydrophilic residues (Ser, Asn, Trp) tend to stay on or fall below the isotropic model trend lines whereas those of hydrophobic amino acids (Ile, Phe) deviate positively from the isotropic trend lines. The growth trends correlate well to the predicted aggregation propensity of individual amino acids. From the metacluster data, we introduce a novel approach to score and predict aggregation propensity of peptides, which can offer a significant improvement over the existing methods in terms of accuracy. Using a set of hexapeptides, we show that the strong negative deviations of Ser metaclusters from the isotropic model leads a prediction of microcrystalline formation for the SFSFSF peptide, whereas the strong positive deviation of Ile leads to prediction or fibril formation for the NININI peptide. Both predictions are confirmed experimentally using ion mobility and TEM measurements. The peptide SISISI is predicted to only weakly aggregate, a prediction confirmed by TEM.
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Affiliation(s)
- Thanh D Do
- Department of Chemistry and Biochemistry and ‡Neuroscience Research Institute and Department of Molecular Cellular and Developmental Biology University of California , Santa Barbara, California 93106, United States
| | - Natália E C de Almeida
- Department of Chemistry and Biochemistry and ‡Neuroscience Research Institute and Department of Molecular Cellular and Developmental Biology University of California , Santa Barbara, California 93106, United States
| | - Nichole E LaPointe
- Department of Chemistry and Biochemistry and ‡Neuroscience Research Institute and Department of Molecular Cellular and Developmental Biology University of California , Santa Barbara, California 93106, United States
| | - Ali Chamas
- Department of Chemistry and Biochemistry and ‡Neuroscience Research Institute and Department of Molecular Cellular and Developmental Biology University of California , Santa Barbara, California 93106, United States
| | - Stuart C Feinstein
- Department of Chemistry and Biochemistry and ‡Neuroscience Research Institute and Department of Molecular Cellular and Developmental Biology University of California , Santa Barbara, California 93106, United States
| | - Michael T Bowers
- Department of Chemistry and Biochemistry and ‡Neuroscience Research Institute and Department of Molecular Cellular and Developmental Biology University of California , Santa Barbara, California 93106, United States
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29
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Benbow SJ, Cook BM, Reifert J, Wozniak KM, Slusher BS, Littlefield BA, Wilson L, Jordan MA, Feinstein SC. Effects of Paclitaxel and Eribulin in Mouse Sciatic Nerve: A Microtubule-Based Rationale for the Differential Induction of Chemotherapy-Induced Peripheral Neuropathy. Neurotox Res 2015; 29:299-313. [DOI: 10.1007/s12640-015-9580-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 11/18/2015] [Accepted: 11/19/2015] [Indexed: 12/15/2022]
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Yu D, Feinstein SC, Valentine MT. Effects of wild type tau and disease-linked tau mutations on microtubule organization and intracellular trafficking. J Biomech 2015; 49:1280-1285. [PMID: 26674472 DOI: 10.1016/j.jbiomech.2015.09.043] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [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: 06/18/2015] [Revised: 09/23/2015] [Accepted: 09/27/2015] [Indexed: 01/17/2023]
Abstract
We investigate the effects of transient expression of wild type (WT) and disease-linked mutations of tau (R406W, P301L, ΔN296) on cytoskeletal organization and cargo transport in COS-7 cells, which are natively tau-free. The introduction of tau proteins (either WT or mutant forms) leads to a dramatic restructuring of the microtubule cytoskeleton, as observed using immunofluorescence microscopy. Yet, this microtubule bundling and aggregation has a modest effect on the speed and travel distance of motor-driven cargo transport, as measured by the motions of fluorescently-labeled lysosomes. This suggests that localized transport events are insensitive to the global structure of the microtubule cytoskeleton. Importantly, we also found no evidence that the disease-linked tau mutants were particularly toxic; in fact we found that expression of mutant and WT tau had similar effects on overall microtubule structure and transport phenotypes.
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Affiliation(s)
- Dezhi Yu
- Department of Materials, University of California, Santa Barbara, Santa Barbara, CA, USA; Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Stuart C Feinstein
- Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA, USA; Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Megan T Valentine
- Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA, USA; Department of Mechanical Engineering, University of California, Santa Barbara, Santa Barbara, CA, USA.
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31
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Chung PJ, Choi MC, Miller HP, Feinstein HE, Raviv U, Li Y, Wilson L, Feinstein SC, Safinya CR. Direct force measurements reveal that protein Tau confers short-range attractions and isoform-dependent steric stabilization to microtubules. Proc Natl Acad Sci U S A 2015; 112:E6416-25. [PMID: 26542680 PMCID: PMC4664379 DOI: 10.1073/pnas.1513172112] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [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] [Indexed: 01/05/2023] Open
Abstract
Microtubules (MTs) are hollow cytoskeletal filaments assembled from αβ-tubulin heterodimers. Tau, an unstructured protein found in neuronal axons, binds to MTs and regulates their dynamics. Aberrant Tau behavior is associated with neurodegenerative dementias, including Alzheimer's. Here, we report on a direct force measurement between paclitaxel-stabilized MTs coated with distinct Tau isoforms by synchrotron small-angle X-ray scattering (SAXS) of MT-Tau mixtures under osmotic pressure (P). In going from bare MTs to MTs with Tau coverage near the physiological submonolayer regime (Tau/tubulin-dimer molar ratio; ΦTau = 1/10), isoforms with longer N-terminal tails (NTTs) sterically stabilized MTs, preventing bundling up to PB ∼ 10,000-20,000 Pa, an order of magnitude larger than bare MTs. Tau with short NTTs showed little additional effect in suppressing the bundling pressure (PB ∼ 1,000-2,000 Pa) over the same range. Remarkably, the abrupt increase in PB observed for longer isoforms suggests a mushroom to brush transition occurring at 1/13 < ΦTau < 1/10, which corresponds to MT-bound Tau with NTTs that are considerably more extended than SAXS data for Tau in solution indicate. Modeling of Tau-mediated MT-MT interactions supports the hypothesis that longer NTTs transition to a polyelectrolyte brush at higher coverages. Higher pressures resulted in isoform-independent irreversible bundling because the polyampholytic nature of Tau leads to short-range attractions. These findings suggest an isoform-dependent biological role for regulation by Tau, with longer isoforms conferring MT steric stabilization against aggregation either with other biomacromolecules or into tight bundles, preventing loss of function in the crowded axon environment.
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Affiliation(s)
- Peter J Chung
- Materials Department, University of California, Santa Barbara, CA 93106; Physics Department, University of California, Santa Barbara, CA 93106; Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93106
| | - Myung Chul Choi
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea
| | - Herbert P Miller
- Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93106; Neuroscience Research Institute, University of California, Santa Barbara, CA 93106
| | - H Eric Feinstein
- Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93106; Neuroscience Research Institute, University of California, Santa Barbara, CA 93106
| | - Uri Raviv
- Institute of Chemistry, Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Youli Li
- Materials Research Laboratory, University of California, Santa Barbara, CA 93106
| | - Leslie Wilson
- Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93106; Neuroscience Research Institute, University of California, Santa Barbara, CA 93106
| | - Stuart C Feinstein
- Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93106; Neuroscience Research Institute, University of California, Santa Barbara, CA 93106
| | - Cyrus R Safinya
- Materials Department, University of California, Santa Barbara, CA 93106; Physics Department, University of California, Santa Barbara, CA 93106; Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93106;
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Abstract
![]()
A peptide fragment of the human tau
protein which stacks to form
neat cross β-sheet fibrils, resembling that found in pathological
aggregation, 273GKVQIINKKLDL284 (here
“R2/WT”), was modified with a spin-label at the N-terminus.
With the resulting peptide, R2/G273C-SL, we probed events at time
scales spanning seconds to hours after aggregation is initiated using
transmission electron microscopy (TEM), thioflavin T (THT) fluorescence,
ion mobility mass spectrometry (IMMS), electron paramagnetic resonance
(EPR), and Overhauser dynamic nuclear polarization (ODNP) to determine
if deliberate changes to its conformational states and population
in solution influence downstream propensity to form fibrillar aggregates.
We find varying solution conditions by adding the osmolyte urea or
TMAO, or simply using different buffers (acetate buffer, phosphate
buffer, or water), produces significant differences in early monomer/dimer
populations and conformations. Crucially, these characteristics of
the peptide in solution state before aggregation
is initiated dictate the fibril formation propensity after aggregation. We conclude the driving forces that accelerate aggregation,
when heparin is added, do not override the subtle intra- or interprotein
interactions induced by the initial solvent conditions. In other words,
the balance of protein–protein vs protein–solvent interactions
present in the initial solution conditions is a critical driving force
for fibril formation.
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Affiliation(s)
- Neil A Eschmann
- Department of Chemistry and Biochemistry and ‡Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California at Santa Barbara , Santa Barbara, California 93106, United States
| | - Thanh D Do
- Department of Chemistry and Biochemistry and ‡Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California at Santa Barbara , Santa Barbara, California 93106, United States
| | - Nichole E LaPointe
- Department of Chemistry and Biochemistry and ‡Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California at Santa Barbara , Santa Barbara, California 93106, United States
| | - Joan-Emma Shea
- Department of Chemistry and Biochemistry and ‡Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California at Santa Barbara , Santa Barbara, California 93106, United States
| | - Stuart C Feinstein
- Department of Chemistry and Biochemistry and ‡Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California at Santa Barbara , Santa Barbara, California 93106, United States
| | - Michael T Bowers
- Department of Chemistry and Biochemistry and ‡Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California at Santa Barbara , Santa Barbara, California 93106, United States
| | - Songi Han
- Department of Chemistry and Biochemistry and ‡Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California at Santa Barbara , Santa Barbara, California 93106, United States
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Ganguly P, Do TD, Larini L, LaPointe NE, Sercel AJ, Shade MF, Feinstein SC, Bowers MT, Shea JE. Tau assembly: the dominant role of PHF6 (VQIVYK) in microtubule binding region repeat R3. J Phys Chem B 2015; 119:4582-93. [PMID: 25775228 PMCID: PMC4428543 DOI: 10.1021/acs.jpcb.5b00175] [Citation(s) in RCA: 120] [Impact Index Per Article: 13.3] [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: 01/19/2023]
Abstract
Self-aggregation of the microtubule-binding protein Tau reduces its functionality and is tightly associated with Tau-related diseases, termed tauopathies. Tau aggregation is also strongly associated with two nucleating six-residue segments, namely PHF6 (VQIVYK) and PHF6* (VQIINK). In this paper, using experiments and computational modeling, we study the self-assembly of individual and binary mixtures of Tau fragments containing PHF6* (R2/wt; (273)GKVQIINKKLDL(284)) and PHF6 (R3/wt; (306)VQIVYKPVDLSK(317)) and a mutant R2/ΔK280 associated with a neurodegenerative tauopathy. The initial stage of aggregation is probed by ion-mobility mass spectrometry, the kinetics of aggregation monitored with Thioflavin T assays, and the morphology of aggregates visualized by transmission electron microscopy. Insights into the structure of early aggregates and the factors stabilizing the aggregates are obtained from replica exchange molecular dynamics simulations. Our data suggest that R3/wt has a much stronger aggregation propensity than either R2/wt or R2/ΔK280. Heterodimers containing R3/wt are less stable than R3/wt homodimers but much more stable than homodimers of R2/wt and R2/ΔK280, suggesting a possible role of PHF6*-PHF6 interactions in initiating the aggregation of full-length Tau. Lastly, R2/ΔK280 binds more strongly to R3/wt than R2/wt, suggesting a possible mechanism for a pathological loss of normal Tau function.
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Affiliation(s)
- Pritam Ganguly
- Department of Chemistry and Biochemistry, University of California at Santa Barbara, Santa Barbara, California, 93106, USA
| | - Thanh D. Do
- Department of Chemistry and Biochemistry, University of California at Santa Barbara, Santa Barbara, California, 93106, USA
| | - Luca Larini
- Department of Chemistry and Biochemistry, University of California at Santa Barbara, Santa Barbara, California, 93106, USA
| | - Nichole E. LaPointe
- Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California at Santa Barbara, Santa Barbara, California, 93106, USA
| | - Alexander J. Sercel
- Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California at Santa Barbara, Santa Barbara, California, 93106, USA
| | - Madeleine F. Shade
- Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California at Santa Barbara, Santa Barbara, California, 93106, USA
| | - Stuart C. Feinstein
- Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California at Santa Barbara, Santa Barbara, California, 93106, USA
| | - Michael T. Bowers
- Department of Chemistry and Biochemistry, University of California at Santa Barbara, Santa Barbara, California, 93106, USA
| | - Joan-Emma Shea
- Department of Chemistry and Biochemistry, University of California at Santa Barbara, Santa Barbara, California, 93106, USA
- Department of Physics, University of California at Santa Barbara, Santa Barbara, California, 93106, USA
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34
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Chung PJ, Choi M, Raviv U, Miller HP, Wilson L, Feinstein SC, Safinya CR. Intrinsically Disordered Map Tau Mediates both Short-Range Attraction and Long-Range Repulsion between Microtubules. Biophys J 2015. [DOI: 10.1016/j.bpj.2014.11.2787] [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: 11/24/2022] Open
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35
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Yu D, LaPointe NE, Guzman E, Pessino V, Wilson L, Feinstein SC, Valentine MT. Tau proteins harboring neurodegeneration-linked mutations impair kinesin translocation in vitro. J Alzheimers Dis 2014; 39:301-14. [PMID: 24150109 DOI: 10.3233/jad-131274] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [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: 11/15/2022]
Abstract
We tested the hypothesis that mutant tau proteins that cause neurodegeneration and dementia differentially alter kinesin translocation along microtubules (MTs) relative to normal tau in vitro. We employed complementary in vitro motility assays using purified recombinant kinesin, purified recombinant tau, and purified bovine brain α:β tubulin to isolate interactions among these components without any contribution by cellular regulatory mechanisms. We found that kinesin translocates slower along MTs assembled by any of three independent tau mutants (4-repeat P301L tau, 4-repeat ΔN296 tau, and 4-repeat R406W tau) relative to its translocation rate along MTs assembled by normal, 4-repeat wild type (WT) tau. Moreover, the R406W mutation exhibited isoform specific effects; while kinesin translocation along 4-repeat R406W tau assembled MTs is slower than along MTs assembled by 4-repeat WT tau, the R406W mutation had no effect in the 3-repeat tau context. These data provide strong support for the notion that aberrant modulation of kinesin translocation is a component of tau-mediated neuronal cell death and dementia. Finally, we showed that assembling MTs with taxol before coating them with mutant tau obscured effects of the mutant tau that were readily apparent using more physiologically relevant MTs assembled with tau alone, raising important issues regarding the use of taxol as an experimental reagent and novel insights into therapeutic mechanisms of taxol action.
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Affiliation(s)
- Dezhi Yu
- Department of Materials, University of California, Santa Barbara, CA, USA
| | - Nichole E LaPointe
- Neuroscience Research Institute, University of California, Santa Barbara, CA, USA Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA, USA
| | - Elmer Guzman
- Neuroscience Research Institute, University of California, Santa Barbara, CA, USA Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA, USA
| | - Veronica Pessino
- College of Creative Studies, University of California, Santa Barbara, CA, USA
| | - Leslie Wilson
- Neuroscience Research Institute, University of California, Santa Barbara, CA, USA Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA, USA
| | - Stuart C Feinstein
- Neuroscience Research Institute, University of California, Santa Barbara, CA, USA Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA, USA
| | - Megan T Valentine
- Neuroscience Research Institute, University of California, Santa Barbara, CA, USA Department of Mechanical Engineering, University of California, Santa Barbara, CA, USA
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Cook BM, Benbow SJ, Wozniak KM, Slusher BS, Littlefield BA, Wilson L, Feinstein SC, Jordan MA. Abstract 5503: Microtubule-targeting agents induce differential myelinated axon degeneration in a mouse model of peripheral neuropathy. Cancer Res 2014. [DOI: 10.1158/1538-7445.am2014-5503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Microtubule-targeting agents (MTAs) have proven useful in treating many types of cancers. However, their efficacy continues to be limited by peripheral neuropathy, a painful and potentially dose-limiting side effect. While the mechanisms of MTA-induced neuropathy remain unclear, evidence suggests that peripheral nerve degeneration contributes to altered nerve activity and neuropathic pain. Recent electrophysiological studies in mice revealed that paclitaxel and ixabepilone reduced peripheral nerve conduction velocity and amplitude, while eribulin, an MTA with a lower incidence of severe peripheral neuropathy, showed no change in these parameters. Here, we sought to test the hypothesis that MTA-induced peripheral neuropathy in mice positively correlates with axon degeneration. We compared the effects of four MTAs with varying incidences of severe neuropathic symptoms (vincristine > ixabepilone = paclitaxel > eribulin). Naïve adult mice were treated at their maximum tolerated dose of each drug (or vehicle) on a Q2Dx3 schedule for 2 weeks. Sciatic nerves were extracted, fixed, sectioned, and visualized by immunofluorescence confocal microscopy. Morphological changes were quantified using Imaris software. Paclitaxel and eribulin resulted in significantly lower myelinated axon densities of 172 ± 14.5 and 264 ± 18.0 axons per 100 μm2 compared to vehicle controls of 371 ± 14.2 and 366 ± 19.3 respectively (mean ± SEM, P < 0.001). Paclitaxel and eribulin also increased the percentage of collapsed nerve fibers, which were identified by fragmented and/or contracted myelin sheaths coupled with a loss of phospho-neurofilament protein signal from the associated axons. The percent of collapsed nerve fibers was 2.2% for eribulin (vs. 0.32% vehicle; P < 0.05) and 6.6% for paclitaxel (vs. 0.21% vehicle; P<0.001). For paclitaxel, nerve fiber collapse occurred more frequently in distal than in proximal nerve sections (P < 0.01). We also observed a unique myelin “halo” morphology in eribulin treated nerves that was not found in any other condition. Surprisingly, vincristine and ixabepilone did not induce detectable nerve degeneration, even though both drugs exhibit a high incidence of severe peripheral neuropathy. Our results indicate that although significant nerve degeneration is present after two weeks of treatment with some MTAs, the extent of these changes does not correlate with the clinical incidence of severe neuropathy. Therefore, although degenerative changes in peripheral nerves may contribute to nerve dysfunction in MTA-induced peripheral neuropathy, especially in the cases of paclitaxel and eribulin, they do not appear to be the only factor underlying this condition. We conclude that additional mechanisms of MTA-induced peripheral neuropathy likely exist which may not be directly related to axonal degeneration. We gratefully thank Eisai Inc for support of this research.
Citation Format: Brett M. Cook, Sarah J. Benbow, Krystyna M. Wozniak, Barbara S. Slusher, Bruce A. Littlefield, Leslie Wilson, Stuart C. Feinstein, Mary Ann Jordan. Microtubule-targeting agents induce differential myelinated axon degeneration in a mouse model of peripheral neuropathy. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5503. doi:10.1158/1538-7445.AM2014-5503
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Affiliation(s)
- Brett M. Cook
- 1Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, CA
| | - Sarah J. Benbow
- 1Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, CA
| | | | - Barbara S. Slusher
- 2Brain Science Institute, Johns Hopkins School of Medicine, Baltimore, MD
| | | | - Leslie Wilson
- 1Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, CA
| | - Stuart C. Feinstein
- 1Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, CA
| | - Mary Ann Jordan
- 1Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, CA
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Shropshire TD, Reifert J, Rajagopalan S, Baker D, Feinstein SC, Daugherty PS. Amyloid β peptide cleavage by kallikrein 7 attenuates fibril growth and rescues neurons from Aβ-mediated toxicity in vitro. Biol Chem 2014; 395:109-18. [PMID: 23989112 DOI: 10.1515/hsz-2013-0230] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Accepted: 08/27/2013] [Indexed: 12/23/2022]
Abstract
The gradual accumulation and assembly of β-amyloid (Aβ) peptide into neuritic plaques is a major pathological hallmark of Alzheimer disease (AD). Proteolytic degradation of Aβ is an important clearance mechanism under normal circumstances, and it has been found to be compromised in those with AD. Here, the extended substrate specificity and Aβ-degrading capacity of kallikrein 7 (KLK7), a serine protease with a unique chymotrypsin-like specificity, was characterized. Preferred peptide substrates of KLK7 identified using a bacterial display substrate library were found to exhibit a consensus motif of RXΦ(Y/F)↓(Y/F)↓(S/A/G/T) or RXΦ(Y/F)↓(S/T/A) (Φ=hydrophobic), which is remarkably similar to the hydrophobic core motif of Aβ (K16L17V18F19F20 A21) that is largely responsible for aggregation propensity. KLK7 was found to cleave after both Phe residues within the core of Aβ42 in vitro, thereby inhibiting Aβ fibril formation and promoting the degradation of preformed fibrils. Finally, the treatment of Aβ oligomer preparations with KLK7, but not inactive pro-KLK7, significantly reduced Aβ42-mediated toxicity to rat hippocampal neurons to the same extent as the known Aβ-degrading protease insulin-degrading enzyme (IDE). Taken together, these results indicate that KLK7 possesses an Aβ-degrading capacity that can ameliorate the toxic effects of the aggregated peptide in vitro.
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Do TD, LaPointe NE, Sangwan S, Teplow DB, Feinstein SC, Sawaya MR, Eisenberg DS, Bowers MT. Factors that drive peptide assembly from native to amyloid structures: experimental and theoretical analysis of [leu-5]-enkephalin mutants. J Phys Chem B 2014; 118:7247-56. [PMID: 24915112 PMCID: PMC4084844 DOI: 10.1021/jp502473s] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
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Five different mutants of [Leu-5]
Enkephalin YGGFL peptide have been investigated for fibril formation
propensities. The early oligomer structures have been probed with
a combination of ion-mobility mass spectrometry and computational
modeling. The two peptides YVIFL and YVVFL form oligomers and amyloid-like
fibrils. YVVFV shows an early stage oligomer distribution similar
to those of the previous two, but amyloid-like aggregates are less
abundant. Atomic resolution X-ray structures of YVVFV show two different
modes of interactions at the dry interface between steric zippers
and pairs of antiparallel β-sheets, but both are less favorable
than the packing motif found in YVVFL. Both YVVFV and YVVFL can form
a Class 6 steric zipper. However, in YVVFV, the strands between mating
sheets are parallel to each other and in YVVFL they are antiparallel.
The overall data highlight the importance of structurally characterizing
high order oligomers within oligomerization pathways in studies of
nanostructure assembly.
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Affiliation(s)
- Thanh D Do
- Department of Chemistry and Biochemistry and ‡Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California , Santa Barbara, California 93106, United States
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Do TD, LaPointe NE, Economou NJ, Buratto SK, Feinstein SC, Shea JE, Bowers MT. Effects of pH and charge state on peptide assembly: the YVIFL model system. J Phys Chem B 2013; 117:10759-68. [PMID: 23937333 DOI: 10.1021/jp406066d] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Peptide oligomerization is necessary but not sufficient for amyloid fibril formation. Here, we use a combination of experiments and simulations to understand how pH influences the aggregation properties of a small hydrophobic peptide, YVIFL, which is a mutant form of [Leu-5]-Enkephalin. Transmission electron microscopy and atomic force microscopy measurements reveal that this peptide forms small aggregates under acidic conditions (pH = 2), but that extensive fibrillization only occurs under basic conditions (pH = 9 and 11). Ion-mobility mass spectrometry identifies key oligomers in the oligomerization process, which are further characterized at an atomistic level by molecular dynamics simulations. These simulations suggest that terminal charges play a critical role in determining aggregation propensity and aggregate morphology. They also reveal the presence of steric zipper oligomers under basic conditions, a possible precursor to fibril formation. Our experiments suggest that multiple aggregation pathways can lead to YVIFL fibrils, and that cooperative and multibody interactions are key mechanistic elements in the early stages of aggregation.
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Affiliation(s)
- Thanh D Do
- Department of Chemistry and Biochemistry, ‡Department of Physics and §Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California at Santa Barbara , Santa Barbara, California, 93106, United States
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Do TD, Economou NJ, LaPointe NE, Kincannon WM, Bleiholder C, Feinstein SC, Teplow DB, Buratto SK, Bowers MT. Factors that drive peptide assembly and fibril formation: experimental and theoretical analysis of Sup35 NNQQNY mutants. J Phys Chem B 2013; 117:8436-46. [PMID: 23802812 DOI: 10.1021/jp4046287] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Residue mutations have substantial effects on aggregation kinetics and propensities of amyloid peptides and their aggregate morphologies. Such effects are attributed to conformational transitions accessed by various types of oligomers such as steric zipper or single β-sheet. We have studied the aggregation propensities of six NNQQNY mutants: NVVVVY, NNVVNV, NNVVNY, VIQVVY, NVVQIY, and NVQVVY in water using a combination of ion-mobility mass spectrometry, transmission electron microscopy, atomic force microscopy, and all-atom molecular dynamics simulations. Our data show a strong correlation between the tendency to form early β-sheet oligomers and the subsequent aggregation propensity. Our molecular dynamics simulations indicate that the stability of a steric zipper structure can enhance the propensity for fibril formation. Such stability can be attained by either hydrophobic interactions in the mutant peptide or polar side-chain interdigitations in the wild-type peptide. The overall results display only modest agreement with the aggregation propensity prediction methods such as PASTA, Zyggregator, and RosettaProfile, suggesting the need for better parametrization and model peptides for these algorithms.
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Affiliation(s)
- Thanh D Do
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
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Larini L, Gessel MM, LaPointe NE, Do TD, Bowers MT, Feinstein SC, Shea JE. Initiation of assembly of tau(273-284) and its ΔK280 mutant: an experimental and computational study. Phys Chem Chem Phys 2013; 15:8916-28. [PMID: 23515417 DOI: 10.1039/c3cp00063j] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The microtubule associated protein tau is essential for the development and maintenance of the nervous system. Tau dysfunction is associated with a class of diseases called tauopathies, in which tau is found in an aggregated form. This paper focuses on a small aggregating fragment of tau, (273)GKVQIINKKLDL(284), encompassing the (PHF6*) region that plays a central role in tau aggregation. Using a combination of simulations and experiments, we probe the self-assembly of this peptide, with an emphasis on characterizing the early steps of aggregation. Ion-mobility mass spectrometry experiments provide a size distribution of early oligomers, TEM studies provide a time course of aggregation, and enhanced sampling molecular dynamics simulations provide atomistically detailed structural information about this intrinsically disordered peptide. Our studies indicate that a point mutation, as well the addition of heparin, lead to a shift in the conformations populated by the earliest oligomers, affecting the kinetics of subsequent fibril formation as well as the morphology of the resulting aggregates. In particular, a mutant associated with a K280 deletion (a mutation that causes a heritable form of neurodegeneration/dementia in the context of full length tau) is seen to aggregate more readily than its wild-type counterpart. Simulations and experiment reveal that the ΔK280 mutant peptide adopts extended conformations to a greater extent than the wild-type peptide, facilitating aggregation through the pre-structuring of the peptide into a fibril-competent structure.
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Affiliation(s)
- Luca Larini
- Department of Physics, University of California at Santa Barbara, Santa Barbara, California 93106, USA
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Needleman DJ, Ojeda-Lopez MA, Raviv U, Miller HP, Li Y, Song C, Feinstein SC, Wilson L, Choi MC, Safinya CR. Ion specific effects in bundling and depolymerization of taxol-stabilized microtubules. Faraday Discuss 2013; 166:31-45. [PMID: 24611267 PMCID: PMC3955895 DOI: 10.1039/c3fd00063j] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [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: 09/12/2023]
Abstract
Microtubules (MTs) are nanometer scale hollow cylindrical biological polyelectrolytes. They are assembled from alpha/beta-tubulin dimers, which stack to form protofilaments (PFs) with lateral interactions between PFs resulting in the curved MT. In cells, MTs and their assemblies are critical components in a range of functions from providing tracks for the transport of cargo to forming the spindle structure during mitosis. Previous studies have, shown that while cations with valence equal to or larger than 3+ tend to assemble tight 3D bundles of taxol-stabilized MTs, certain divalent cations induce relatively loose 2D bundles of different symmetry (D. J. Needleman et al., Proc. Natl. Acad. Sci. U. S. A., 2004, 101, 16099). Similarly, divalent cations form 2D bundles of DNA adsorbed on cationic membranes (I. Koltover et al., Proc. Natl. Acad. Sci. U. S. A., 2000, 97, 14046). The bundling behavior for these biological polyelectrolyte systems is qualitatively in agreement with current theory. Here, we present results which show that, unlike the case for DNA adsorbed on cationic membranes, bundling of taxol-stabilized MTs occurs only for certain divalent cations above a critical ion concentration (e.g. Ca2+, Sr2+, Ba2+). Instead, many divalent cations pre-empt the bundling transition and depolymerize taxol-stabilized MTs at a lower counterion concentration. Although previous cryogenic TEM has shown that, in the absence of taxol, Ca2+ depolymerizes MTs assembling in buffers containing GTP (guanosine triphosphate), our finding is surprising given the know stabilizing effects of taxol on GDP (guanosine diphosphate)-MTs. The ion concentration required for MT depolymerization decreases with increasing atomic number for the divalents Mg2+, Mn2+, Co2+, and Zn2+. GdCl3 (3+) is found to be extremely efficient at MT depolymerization requiring ion concentrations of about 1 mM, while oligolysine(2+), is observed not to depolymerize MTs at concentrations as high as 144 mM. The surprising MT depolymerization results are discussed in the context of divalents either disrupting lateral interactions between PFs (which are strengthened for taxol containing beta-tubulin) or interfering with taxol's ability to induce flexibility at the interface between two tubulin dimers in the same PF (which has been recently suggested as a mechanism by which taxol stabilizes MTs post-hydrolysis with the induced flexibility counteracting the kink between GDP-tublin dimers in a PF).
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Affiliation(s)
- Daniel J. Needleman
- Materials, Physics, and Molecular, Cellular, and Developmental Biology Departments, University of California, Santa Barbara, CA 93106, USA. ; Fax +1 805 893 8797; Tel +1 805 893 8635
| | - Miguel A. Ojeda-Lopez
- Materials, Physics, and Molecular, Cellular, and Developmental Biology Departments, University of California, Santa Barbara, CA 93106, USA. ; Fax +1 805 893 8797; Tel +1 805 893 8635
| | - Uri Raviv
- Materials, Physics, and Molecular, Cellular, and Developmental Biology Departments, University of California, Santa Barbara, CA 93106, USA. ; Fax +1 805 893 8797; Tel +1 805 893 8635
| | - Herbert P. Miller
- Molecular, Cellular, & Developmental Biology Department & Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA
| | - Youli Li
- Materials Research Laboratory, University of California, Santa Barbara, CA 93106, USA
| | - Chaeyeon Song
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Stuart C. Feinstein
- Molecular, Cellular, & Developmental Biology Department & Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA
| | - Leslie Wilson
- Molecular, Cellular, & Developmental Biology Department & Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA
| | - Myung Chul Choi
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Cyrus R. Safinya
- Materials, Physics, and Molecular, Cellular, and Developmental Biology Departments, University of California, Santa Barbara, CA 93106, USA. ; Fax +1 805 893 8797; Tel +1 805 893 8635
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Chung PJ, Deek J, Feinstein HE, Miller H, Chul Choi M, Wilson L, Feinstein SC, Safinya CR. A Structure-Function Study of Map Tau: Analyzing Distinct Map Tau Domains in Mediating Microtubule Assembly and Bundling using Synchrotron SAXS. Biophys J 2012. [DOI: 10.1016/j.bpj.2011.11.3799] [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: 10/14/2022] Open
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44
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Safinya CR, Raviv U, Needleman DJ, Zidovska A, Choi MC, Ojeda-Lopez MA, Ewert KK, Li Y, Miller HP, Quispe J, Carragher B, Potter CS, Kim MW, Feinstein SC, Wilson L. Nanoscale assembly in biological systems: from neuronal cytoskeletal proteins to curvature stabilizing lipids. Adv Mater 2011; 23:2260-70. [PMID: 21506171 PMCID: PMC3864889 DOI: 10.1002/adma.201004647] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2010] [Indexed: 05/30/2023]
Abstract
The review will describe experiments inspired by the rich variety of bundles and networks of interacting microtubules (MT), neurofilaments, and filamentous-actin in neurons where the nature of the interactions, structures, and structure-function correlations remain poorly understood. We describe how three-dimensional (3D) MT bundles and 2D MT bundles may assemble, in cell free systems in the presence of counter-ions, revealing structures not predicted by polyelectrolyte theories. Interestingly, experiments reveal that the neuronal protein tau, an abundant MT-associated-protein in axons, modulates the MT diameter providing insight for the control of geometric parameters in bio- nanotechnology. In another set of experiments we describe lipid-protein-nanotubes, and lipid nano-tubes and rods, resulting from membrane shape evolution processes involving protein templates and curvature stabilizing lipids. Similar membrane shape changes, occurring in cells for the purpose of specific functions, are induced by interactions between membranes and proteins. The biological materials systems described have applications in bio-nanotechnology.
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Affiliation(s)
- Cyrus R Safinya
- Materials, Physics, and Molecular, Cellular, and Developmental Biology Departments, University of California-Santa Barbara, CA 93106, USA.
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Reifert J, Hartung-Cranston D, Feinstein SC. Amyloid beta-mediated cell death of cultured hippocampal neurons reveals extensive Tau fragmentation without increased full-length tau phosphorylation. J Biol Chem 2011; 286:20797-811. [PMID: 21482827 DOI: 10.1074/jbc.m111.234674] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
A variety of genetic and biochemical evidence suggests that amyloid β (Aβ) oligomers promote downstream errors in Tau action, in turn inducing neuronal dysfunction and cell death in Alzheimer and related dementias. To better understand molecular mechanisms involved in Aβ-mediated neuronal cell death, we have treated primary rat hippocampal cultures with Aβ oligomers and examined the resulting cellular changes occurring before and during the induction of cell death with a focus on altered Tau biochemistry. The most rapid neuronal responses upon Aβ administration are activation of caspase 3/7 and calpain proteases. Aβ also appears to reduce Akt and Erk1/2 kinase activities while increasing GSK3β and Cdk5 activities. Shortly thereafter, substantial Tau degradation begins, generating relatively stable Tau fragments. Only a very small fraction of full-length Tau remains intact after 4 h of Aβ treatment. In conflict with expectations based on suggested increases of GSK3β and Cdk5 activities, Aβ does not cause any major increases in phosphorylation of full-length Tau as assayed by immunoblotting one-dimensional gels with 11 independent site- and phospho-specific anti-Tau antibodies as well as by immunoblotting two-dimensional gels probed with a pan-Tau antibody. There are, however, subtle and transient increases in Tau phosphorylation at 3-4 specific sites before its degradation. Taken together, these data are consistent with the notion that Aβ-mediated neuronal cell death involves the loss of full-length Tau and/or the generation of toxic fragments but does not involve or require hyperphosphorylation of full-length Tau.
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Affiliation(s)
- Jack Reifert
- Neuroscience Research Institute and Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, California 93106, USA
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Kiris E, Ventimiglia D, Sargin ME, Gaylord MR, Altinok A, Rose K, Manjunath BS, Jordan MA, Wilson L, Feinstein SC. Combinatorial Tau pseudophosphorylation: markedly different regulatory effects on microtubule assembly and dynamic instability than the sum of the individual parts. J Biol Chem 2011; 286:14257-70. [PMID: 21288907 DOI: 10.1074/jbc.m111.219311] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Tau is a multiply phosphorylated protein that is essential for the development and maintenance of the nervous system. Errors in Tau action are associated with Alzheimer disease and related dementias. A huge literature has led to the widely held notion that aberrant Tau hyperphosphorylation is central to these disorders. Unfortunately, our mechanistic understanding of the functional effects of combinatorial Tau phosphorylation remains minimal. Here, we generated four singly pseudophosphorylated Tau proteins (at Thr(231), Ser(262), Ser(396), and Ser(404)) and four doubly pseudophosphorylated Tau proteins using the same sites. Each Tau preparation was assayed for its abilities to promote microtubule assembly and to regulate microtubule dynamic instability in vitro. All four singly pseudophosphorylated Tau proteins exhibited loss-of-function effects. In marked contrast to the expectation that doubly pseudophosphorylated Tau would be less functional than either of its corresponding singly pseudophosphorylated forms, all of the doubly pseudophosphorylated Tau proteins possessed enhanced microtubule assembly activity and were more potent at regulating dynamic instability than their compromised singly pseudophosphorylated counterparts. Thus, the effects of multiple pseudophosphorylations were not simply the sum of the effects of the constituent single pseudophosphorylations; rather, they were generally opposite to the effects of singly pseudophosphorylated Tau. Further, despite being pseudophosphorylated at different sites, the four singly pseduophosphorylated Tau proteins often functioned similarly, as did the four doubly pseudophosphorylated proteins. These data lead us to reassess the conventional view of combinatorial phosphorylation in normal and pathological Tau action. They may also be relevant to the issue of combinatorial phosphorylation as a general regulatory mechanism.
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Affiliation(s)
- Erkan Kiris
- Neuroscience Research Institute and Department of Molecular and Cellular and Developmental Biology, University of California, Santa Barbara, California 93106, USA
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Choi M, Chung PJ, Raviv U, Li Y, Kiris E, Miller HP, Wilson L, Feinstein SC, Safinya CR. A direct Force Measurement Reveals that Human Microtubule-Associated-Protein tau Modulates the Interactions Betweem Microtubules in an Isoform Dependent Manner. Biophys J 2011. [DOI: 10.1016/j.bpj.2010.12.2638] [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: 11/16/2022] Open
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Peck A, Sargin ME, LaPointe NE, Rose K, Manjunath BS, Feinstein SC, Wilson L. Tau isoform-specific modulation of kinesin-driven microtubule gliding rates and trajectories as determined with tau-stabilized microtubules. Cytoskeleton (Hoboken) 2010; 68:44-55. [PMID: 21162159 DOI: 10.1002/cm.20494] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2010] [Revised: 10/01/2010] [Accepted: 10/01/2010] [Indexed: 11/10/2022]
Abstract
We have utilized tau-assembled and tau-stabilized microtubules (MTs), in the absence of taxol, to investigate the effects of tau isoforms with three and four MT binding repeats upon kinesin-driven MT gliding. MTs were assembled in the presence of either 3-repeat tau (3R tau) or 4-repeat tau (4R tau) at tau:tubulin dimer molar ratios that approximate those found in neurons. MTs assembled with 3R tau glided at 31.1 μm/min versus 25.8 μm/min for 4R tau, a statistically significant 17% difference. Importantly, the gliding rates for either isoform did not change over a fourfold range of tau concentrations. Further, tau-assembled MTs underwent minimal dynamic instability behavior while gliding and moved with linear trajectories. In contrast, MTs assembled with taxol in the absence of tau displayed curved gliding trajectories. Interestingly, addition of 4R tau to taxol-stabilized MTs restored linear gliding, while addition of 3R tau did not. The data are consistent with the ideas that (i) 3R and 4R tau-assembled MTs possess at least some isoform-specific features that impact upon kinesin translocation, (ii) tau-assembled MTs possess different structural features than do taxol-assembled MTs, and (iii) some features of tau-assembled MTs can be masked by prior assembly by taxol. The differences in kinesin-driven gliding between 3R and 4R tau suggest important features of tau function related to the normal shift in tau isoform composition that occurs during neural development as well as in neurodegeneration caused by altered expression ratios of otherwise normal tau isoforms.
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Affiliation(s)
- Austin Peck
- Neuroscience Research Institute, University of California, Santa Barbara, California, USA
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Yenjerla M, LaPointe NE, Lopus M, Cox C, Jordan MA, Feinstein SC, Wilson L. The neuroprotective peptide NAP does not directly affect polymerization or dynamics of reconstituted neural microtubules. J Alzheimers Dis 2010; 19:1377-86. [PMID: 20061604 DOI: 10.3233/jad-2010-1335] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
NAP (Asn-Ala-Pro-Val-Ser-Ile-Pro-Gln) is a neuroprotective peptide that shows cognitive protection in patients with amnestic mild cognitive impairment, a precursor to Alzheimer's disease. NAP exhibits potent neuroprotective properties in several in vivo and cellular models of neural injury. While NAP has been found in many studies to affect microtubule assembly and/or stability in neuronal and glial cells at fM concentrations, it has remained unclear whether NAP acts directly or indirectly on tubulin or microtubules. We analyzed the effects of NAP (1 fM-1 microM) on the assembly of reconstituted bovine brain microtubules in vitro and found that it did not significantly (p< 0.05) alter polymerization of either purified tubulin or of a mixture of tubulin and unfractionated microtubule-associated proteins. NAP also had no significant effect (p < 0.05) on the growing and shortening dynamics of steady-state microtubules at their plus ends, nor did it alter the polymerization or dynamics of microtubules assembled in the presence of 3-repeat or 4-repeat tau. Thus, the neuroprotective activity of NAP does not appear to involve a direct action on the polymerization or dynamics of purified tubulin or microtubules.
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Affiliation(s)
- Mythili Yenjerla
- Department of Molecular, The Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106-9610, USA
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Xu W, Xi B, Wu J, An H, Zhu J, Abassi Y, Feinstein SC, Gaylord M, Geng B, Yan H, Fan W, Sui M, Wang X, Xu X. Natural product derivative Bis(4-fluorobenzyl)trisulfide inhibits tumor growth by modification of beta-tubulin at Cys 12 and suppression of microtubule dynamics. Mol Cancer Ther 2010; 8:3318-30. [PMID: 19996274 DOI: 10.1158/1535-7163.mct-09-0548] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Bis(4-fluorobenzyl)trisulfide (BFBTS) is a synthetic molecule derived from a bioactive natural product, dibenzyltrisulfide, found in a subtropical shrub, Petiveria allieacea. BFBTS has potent anticancer activities to a broad spectrum of tumor cell lines with IC50 values from high nanomolar to low micromolar and showed equal anticancer potency between tumor cell lines overexpressing multidrug-resistant gene, MDR1 (MCF7/adr line and KBv200 line), and their parental MCF7 line and KB lines. BFBTS inhibited microtubule polymerization dynamics in MCF7 cells, at a low nanomolar concentration of 54 nmol/L, while disrupting microtubule filaments in cells at low micromolar concentration of 1 micromol/L. Tumor cells treated with BFBTS were arrested at G2-M phase, conceivably resulting from BFBTS-mediated antimicrotubule activities. Mass spectrometry studies revealed that BFBTS bound and modified beta-tubulin at residue Cys12, forming beta-tubulin-SS-fluorobenzyl. The binding site differs from known antimicrotubule agents, suggesting that BFBTS functions as a novel antimicrotubule agent. BFBTS at a dose of 25 mg/kg inhibited tumor growth with relative tumor growth rates of 19.91%, 18.5%, and 23.42% in A549 lung cancer, Bcap-37 breast cancer, and SKOV3 ovarian cancer xenografts, respectively. Notably, BFBTS was more potent against MDR1-overexpressing MCF7/adr breast cancer xenografts with a relative tumor growth rate of 12.3% than paclitaxel with a rate of 43.0%. BFBTS displays a novel antimicrotubule agent with potentials for cancer therapeutics.
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Affiliation(s)
- Wanhong Xu
- Hangzhou High Throughput Drug Screening Center, ACEA Biosciences, Inc., 6779 Mesa Ridge Road, Suite 100, San Diego, CA 92121, USA
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