101
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Jenkins BV, Saunders HAJ, Record HL, Johnson-Schlitz DM, Wildonger J. Effects of mutating α-tubulin lysine 40 on sensory dendrite development. J Cell Sci 2017; 130:4120-4131. [PMID: 29122984 PMCID: PMC5769580 DOI: 10.1242/jcs.210203] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 11/06/2017] [Indexed: 12/28/2022] Open
Abstract
Microtubules are essential for neuronal structure and function. Axonal and dendritic microtubules are enriched in post-translational modifications that impact microtubule dynamics, transport and microtubule-associated proteins. Acetylation of α-tubulin lysine 40 (K40) is a prominent and conserved modification of neuronal microtubules. However, the cellular role of microtubule acetylation remains controversial. To resolve how microtubule acetylation might affect neuronal morphogenesis, we mutated endogenous α-tubulin in vivo using a new Drosophila strain that facilitates the rapid knock-in of designer αTub84B alleles (the predominant α-tubulin-encoding gene in flies). Leveraging our new strain, we found that microtubule acetylation, as well as polyglutamylation and (de)tyrosination, is not essential for survival. However, we found that dendrite branch refinement in sensory neurons relies on α-tubulin K40. Mutagenesis of K40 reveals moderate yet significant changes in dendritic lysosome transport, microtubule polymerization and Futsch protein distribution in dendrites but not in axons. Our studies point to an unappreciated role for α-tubulin K40 and acetylation in dendrite morphogenesis. While our results are consistent with the idea that acetylation tunes microtubule function within neurons, they also suggest there may be an acetylation-independent requirement for α-tubulin K40. This article has an associated First Person interview with the first author of the paper. Highlighted Article: Neurons are enriched in post-translationally modified microtubules. Targeted mutagenesis of endogenous α-tubulin in flies reveals that dendrite branch refinement is altered by acetylation-blocking mutations.
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Affiliation(s)
- Brian V Jenkins
- Biochemistry Department, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Harriet A J Saunders
- Biochemistry Department, University of Wisconsin-Madison, Madison, WI 53706, USA.,Integrated Program in Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Helena L Record
- Biochemistry Department, University of Wisconsin-Madison, Madison, WI 53706, USA
| | | | - Jill Wildonger
- Biochemistry Department, University of Wisconsin-Madison, Madison, WI 53706, USA
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102
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Wloga D, Joachimiak E, Fabczak H. Tubulin Post-Translational Modifications and Microtubule Dynamics. Int J Mol Sci 2017; 18:ijms18102207. [PMID: 29065455 PMCID: PMC5666887 DOI: 10.3390/ijms18102207] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 10/12/2017] [Accepted: 10/19/2017] [Indexed: 11/24/2022] Open
Abstract
Microtubules are hollow tube-like polymeric structures composed of α,β-tubulin heterodimers. They play an important role in numerous cellular processes, including intracellular transport, cell motility and segregation of the chromosomes during cell division. Moreover, microtubule doublets or triplets form a scaffold of a cilium, centriole and basal body, respectively. To perform such diverse functions microtubules have to differ in their properties. Post-translational modifications are one of the factors that affect the properties of the tubulin polymer. Here we focus on the direct and indirect effects of post-translational modifications of tubulin on microtubule dynamics.
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Affiliation(s)
- Dorota Wloga
- Laboratory of Cytoskeleton and Cilia Biology, Department of Cell Biology, Nencki Institute of Experimental Biology of Polish Academy of Sciences, 3 Pasteur Str., 02-093 Warsaw, Poland.
| | - Ewa Joachimiak
- Laboratory of Cytoskeleton and Cilia Biology, Department of Cell Biology, Nencki Institute of Experimental Biology of Polish Academy of Sciences, 3 Pasteur Str., 02-093 Warsaw, Poland.
| | - Hanna Fabczak
- Laboratory of Cytoskeleton and Cilia Biology, Department of Cell Biology, Nencki Institute of Experimental Biology of Polish Academy of Sciences, 3 Pasteur Str., 02-093 Warsaw, Poland.
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103
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Vemu A, Atherton J, Spector JO, Moores CA, Roll-Mecak A. Tubulin isoform composition tunes microtubule dynamics. Mol Biol Cell 2017; 28:3564-3572. [PMID: 29021343 PMCID: PMC5706985 DOI: 10.1091/mbc.e17-02-0124] [Citation(s) in RCA: 116] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 09/25/2017] [Accepted: 10/03/2017] [Indexed: 12/30/2022] Open
Abstract
We report the cryo-EM structure and dynamic parameters for unmodified α1B/βI+βIVb microtubules. These microtubules display markedly different dynamics compared to heterogeneous brain microtubules, and their dynamic parameters can be proportionally tuned by the addition of a recombinant neuronal tubulin isoform with different dynamic properties. Microtubules polymerize and depolymerize stochastically, a behavior essential for cell division, motility, and differentiation. While many studies advanced our understanding of how microtubule-associated proteins tune microtubule dynamics in trans, we have yet to understand how tubulin genetic diversity regulates microtubule functions. The majority of in vitro dynamics studies are performed with tubulin purified from brain tissue. This preparation is not representative of tubulin found in many cell types. Here we report the 4.2-Å cryo-electron microscopy (cryo-EM) structure and in vitro dynamics parameters of α1B/βI+βIVb microtubules assembled from tubulin purified from a human embryonic kidney cell line with isoform composition characteristic of fibroblasts and many immortalized cell lines. We find that these microtubules grow faster and transition to depolymerization less frequently compared with brain microtubules. Cryo-EM reveals that the dynamic ends of α1B/βI+βIVb microtubules are less tapered and that these tubulin heterodimers display lower curvatures. Interestingly, analysis of EB1 distributions at dynamic ends suggests no differences in GTP cap sizes. Last, we show that the addition of recombinant α1A/βIII tubulin, a neuronal isotype overexpressed in many tumors, proportionally tunes the dynamics of α1B/βI+βIVb microtubules. Our study is an important step toward understanding how tubulin isoform composition tunes microtubule dynamics.
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Affiliation(s)
- Annapurna Vemu
- Cell Biology and Biophysics Unit, National Institute of Neurological Disorders and Stroke, Lung and Blood Institute, Bethesda, MD 20892
| | - Joseph Atherton
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck College, University of London, London WC1E 7HX, United Kingdom
| | - Jeffrey O Spector
- Cell Biology and Biophysics Unit, National Institute of Neurological Disorders and Stroke, Lung and Blood Institute, Bethesda, MD 20892
| | - Carolyn A Moores
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck College, University of London, London WC1E 7HX, United Kingdom
| | - Antonina Roll-Mecak
- Cell Biology and Biophysics Unit, National Institute of Neurological Disorders and Stroke, Lung and Blood Institute, Bethesda, MD 20892 .,Biophysics Center, National Heart, Lung and Blood Institute, Bethesda, MD 20892
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104
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Cartelli D, Amadeo A, Calogero AM, Casagrande FVM, De Gregorio C, Gioria M, Kuzumaki N, Costa I, Sassone J, Ciammola A, Hattori N, Okano H, Goldwurm S, Roybon L, Pezzoli G, Cappelletti G. Parkin absence accelerates microtubule aging in dopaminergic neurons. Neurobiol Aging 2017; 61:66-74. [PMID: 29040870 DOI: 10.1016/j.neurobiolaging.2017.09.010] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 08/24/2017] [Accepted: 09/08/2017] [Indexed: 02/01/2023]
Abstract
Loss-of-function caused by mutations in the parkin gene (PARK2) lead to early-onset familial Parkinson's disease. Recently, mechanistic studies proved the ability of parkin in regulating mitochondria homeostasis and microtubule (MT) stability. Looking at these systems during aging of PARK2 knockout mice, we found that loss of parkin induced an accelerated (over)acetylation of MT system both in dopaminergic neuron cell bodies and fibers, localized in the substantia nigra and corpus striatum, respectively. Interestingly, in PARK2 knockout mice, changes of MT stability preceded the alteration of mitochondria transport. Moreover, in-cell experiments confirmed that loss of parkin affects mitochondria mobility and showed that this defect depends on MT system as it is rescued by paclitaxel, a well-known MT-targeted agent. Furthermore, both in PC12 neuronal cells and in patients' induced pluripotent stem cell-derived midbrain neurons, we observed that parkin deficiencies cause the fragmentation of stable MTs. Therefore, we suggest that parkin acts as a regulator of MT system during neuronal aging, and we endorse the hypothesis that MT dysfunction may be crucial in the pathogenesis of Parkinson's disease.
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Affiliation(s)
- Daniele Cartelli
- Department of Biosciences, Università degli Studi di Milano, Milano, Italy.
| | - Alida Amadeo
- Department of Biosciences, Università degli Studi di Milano, Milano, Italy
| | | | | | | | - Mariarosa Gioria
- Department of Biosciences, Università degli Studi di Milano, Milano, Italy
| | - Naoko Kuzumaki
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
| | - Ilaria Costa
- Department of Biosciences, Università degli Studi di Milano, Milano, Italy
| | - Jenny Sassone
- Division of Neuroscience, San Raffaele Scientific Institute and Vita-Salute University, Milano, Italy
| | - Andrea Ciammola
- Department of Neurology and Laboratory of Neuroscience, IRCCS Istituto Auxologico Italiano, Cusano Milanino, MI, Italy
| | - Nobutaka Hattori
- Department of Neurology, Juntendo University School of Medicine, Tokyo, Japan
| | - Hideyuki Okano
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
| | | | - Laurent Roybon
- Stem Cell laboratory for CNS Disease Modeling, Wallenberg Neuroscience Center, Department of Experimental Medical Science, Lund University, BMC A10, Lund, Sweden; Strategic Research Area MultiPark and Lund Stem Cell Center, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Gianni Pezzoli
- Parkinson Institute, ASST G.Pini-CTO, ex ICP, Milano, Italy
| | - Graziella Cappelletti
- Department of Biosciences, Università degli Studi di Milano, Milano, Italy; Center of Excellence of Neurodegenerative Diseases, Università degli Studi di Milano, Milano, Italy.
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105
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Human histone deacetylase 6 shows strong preference for tubulin dimers over assembled microtubules. Sci Rep 2017; 7:11547. [PMID: 28912522 PMCID: PMC5599508 DOI: 10.1038/s41598-017-11739-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 08/29/2017] [Indexed: 12/31/2022] Open
Abstract
Human histone deacetylase 6 (HDAC6) is the major deacetylase responsible for removing the acetyl group from Lys40 of α-tubulin (αK40), which is located lumenally in polymerized microtubules. Here, we provide a detailed kinetic analysis of tubulin deacetylation and HDAC6/microtubule interactions using individual purified components. Our data unequivocally show that free tubulin dimers represent the preferred HDAC6 substrate, with a K M value of 0.23 µM and a deacetylation rate over 1,500-fold higher than that of assembled microtubules. We attribute the lower deacetylation rate of microtubules to both longitudinal and lateral lattice interactions within tubulin polymers. Using TIRF microscopy, we directly visualized stochastic binding of HDAC6 to assembled microtubules without any detectable preferential binding to microtubule tips. Likewise, indirect immunofluorescence microscopy revealed that microtubule deacetylation by HDAC6 is carried out stochastically along the whole microtubule length, rather than from the open extremities. Our data thus complement prior studies on tubulin acetylation and further strengthen the rationale for the correlation between tubulin acetylation and microtubule age.
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106
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RCCD1 depletion attenuates TGF-β-induced EMT and cell migration by stabilizing cytoskeletal microtubules in NSCLC cells. Cancer Lett 2017; 400:18-29. [DOI: 10.1016/j.canlet.2017.04.021] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 03/23/2017] [Accepted: 04/16/2017] [Indexed: 12/22/2022]
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107
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ATAT1 is essential for regulation of homeostasis-retaining cellular responses in corticotrophs along hypothalamic-pituitary-adrenal axis. Cell Tissue Res 2017; 370:169-178. [PMID: 28687926 DOI: 10.1007/s00441-017-2654-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 05/30/2017] [Indexed: 12/22/2022]
Abstract
The production and secretion of adrenocorticotropin, a proopiomelanocortin (POMC)-derived hormone, by corticotrophs in the anterior pituitary, is regulated by corticotrophin-releasing hormone (CRH) and glucocorticoids. We have previously demonstrated that adrenalectomy induces α-tubulin N-acetyltransferase 1 (ATAT1) expression and α-tubulin acetylation in corticotrophs. However, the regulatory mechanism of ATAT1 expression and the function of acetylated microtubules in corticotrophs are unclear. Here, we analyze the effect of CRH or dexamethasone on Atat1 expression in the mouse corticotroph AtT20 cell line. The expression of Atat1 was increased by CRH and decreased by dexamethasone in AtT20 cells. We examined the effect of Atat1 knockdown on the expression of POMC-associated genes and the dexamethasone-induced nuclear translocation of glucocorticoid receptor (GR) by real-time polymerase chain reaction and Western blot analysis, respectively. Atat1 knockdown resulted in a significant increase in the expression of ACTH-producing genes and decreased the dexamethasone-induced nuclear translocation of GR accompanied with a reduction in α-tubulin acetylation. Atat1 overexpression resulted in a significant increase in α-tubulin acetylation and the dexamethasone-induced nuclear translocation of GR. These results suggest that the acetylated microtubules function as the rail-line for the transportation of GR into the nucleus. We conclude that ATAT1 finely tunes the cellular responses of corticotrophs to hormonal stimulation through an intracellular feedback circuit.
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108
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Wloga D, Joachimiak E, Louka P, Gaertig J. Posttranslational Modifications of Tubulin and Cilia. Cold Spring Harb Perspect Biol 2017; 9:cshperspect.a028159. [PMID: 28003186 DOI: 10.1101/cshperspect.a028159] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Tubulin undergoes several highly conserved posttranslational modifications (PTMs) including acetylation, detyrosination, glutamylation, and glycylation. These PTMs accumulate on a subset of microtubules that are long-lived, including those in the basal bodies and axonemes. Tubulin PTMs are distributed nonuniformly. In the outer doublet microtubules of the axoneme, the B-tubules are highly enriched in the detyrosinated, polyglutamylated, and polyglycylated tubulin, whereas the A-tubules contain mostly unmodified tubulin. The nonuniform patterns of tubulin PTMs may functionalize microtubules in a position-dependent manner. Recent studies indicate that tubulin PTMs contribute to the assembly, disassembly, maintenance, and motility of cilia. In particular, tubulin glutamylation has emerged as a key PTM that affects ciliary motility through regulation of axonemal dynein arms and controls the stability and length of the axoneme.
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Affiliation(s)
- Dorota Wloga
- Laboratory of Cytoskeleton and Cilia Biology, Department of Cell Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland
| | - Ewa Joachimiak
- Laboratory of Cytoskeleton and Cilia Biology, Department of Cell Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland
| | - Panagiota Louka
- Department of Cellular Biology, University of Georgia, Athens, Georgia 30602
| | - Jacek Gaertig
- Department of Cellular Biology, University of Georgia, Athens, Georgia 30602
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109
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Barlan K, Gelfand VI. Microtubule-Based Transport and the Distribution, Tethering, and Organization of Organelles. Cold Spring Harb Perspect Biol 2017; 9:9/5/a025817. [PMID: 28461574 DOI: 10.1101/cshperspect.a025817] [Citation(s) in RCA: 127] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
SUMMARYMicrotubules provide long tracks along which a broad range of organelles and vesicles are transported by kinesin and dynein motors. Motor protein complexes also tether cargoes to cytoskeletal filaments, helping facilitate their interaction and communication. The generation of biochemically distinct microtubule subpopulations allows subsets of motors to recognize a given microtubule identity, allowing further organization within the cytoplasm. Both transport and tethering are spatiotemporally regulated through multiple modes, including acute modification of both motor-cargo and motor-track associations by various physiological signals. Strict regulation of intracellular transport is particularly important in specialized cell types such as neurons. Here, we review general mechanisms by which cargo transport is controlled and also highlight examples of transport regulated by multiple mechanisms.
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Affiliation(s)
- Kari Barlan
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, Illinois 60637
| | - Vladimir I Gelfand
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611
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110
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Plaud C, Joshi V, Marinello M, Pastré D, Galli T, Curmi PA, Burgo A. Spastin regulates VAMP7-containing vesicles trafficking in cortical neurons. Biochim Biophys Acta Mol Basis Dis 2017; 1863:1666-1677. [PMID: 28392418 DOI: 10.1016/j.bbadis.2017.04.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 04/04/2017] [Accepted: 04/06/2017] [Indexed: 01/03/2023]
Abstract
Alteration of axonal transport has emerged as a common precipitating factor in several neurodegenerative disorders including Human Spastic Paraplegia (HSP). Mutations of the SPAST (SPG4) gene coding for the spastin protein account for 40% of all autosomal dominant uncomplicated HSP. By cleaving microtubules, spastin regulates several cellular processes depending on microtubule dynamics including intracellular membrane trafficking. Axonal transport is fundamental for the viability of motor neurons which often have very long axons and thus require efficient communication between the cell body and its periphery. Here we found that the anterograde velocity of VAMP7 vesicles, but not that of VAMP2, two vesicular-SNARE proteins implicated in neuronal development, is enhanced in SPG4-KO neurons. We showed that this effect is associated with a slight increase of the level of acetylated tubulin in SPG4-KO neurons and correlates with an enhanced activity of kinesin-1 motors. Interestingly, we demonstrated that an artificial increase of acetylated tubulin by drugs reproduces the effect of Spastin KO on VAMP7 axonal dynamics but also increased its retrograde velocity. Finally, we investigated the effect of microtubule targeting agents which rescue axonal swellings, on VAMP7 and microtubule dynamics. Our results suggest that microtubule stabilizing agents, such as taxol, may prevent the morphological defects observed in SPG4-KO neurons not simply by restoring the altered anterograde transport to basal levels but rather by increasing the retrograde velocity of axonal cargoes.
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Affiliation(s)
- C Plaud
- Structure and Activity of Normal and Pathological Biomolecules, INSERM U1204, Université Paris-Saclay, Université d' Evry, France
| | - V Joshi
- Structure and Activity of Normal and Pathological Biomolecules, INSERM U1204, Université Paris-Saclay, Université d' Evry, France
| | - M Marinello
- Structure and Activity of Normal and Pathological Biomolecules, INSERM U1204, Université Paris-Saclay, Université d' Evry, France
| | - D Pastré
- Structure and Activity of Normal and Pathological Biomolecules, INSERM U1204, Université Paris-Saclay, Université d' Evry, France
| | - T Galli
- Inserm URL U950, Institut Jacques Monod, France
| | - P A Curmi
- Structure and Activity of Normal and Pathological Biomolecules, INSERM U1204, Université Paris-Saclay, Université d' Evry, France
| | - A Burgo
- Structure and Activity of Normal and Pathological Biomolecules, INSERM U1204, Université Paris-Saclay, Université d' Evry, France.
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111
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Portran D, Schaedel L, Xu Z, Théry M, Nachury MV. Tubulin acetylation protects long-lived microtubules against mechanical ageing. Nat Cell Biol 2017; 19:391-398. [PMID: 28250419 PMCID: PMC5376231 DOI: 10.1038/ncb3481] [Citation(s) in RCA: 295] [Impact Index Per Article: 42.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 01/27/2017] [Indexed: 12/13/2022]
Abstract
Long-lived microtubules endow the eukaryotic cell with long-range transport abilities. While long-lived microtubules are acetylated on Lys40 of α-tubulin (αK40), acetylation takes place after stabilization and does not protect against depolymerization. Instead, αK40 acetylation has been proposed to mechanically stabilize microtubules. Yet how modification of αK40, a residue exposed to the microtubule lumen and inaccessible to microtubule-associated proteins and motors, could affect microtubule mechanics remains an open question. Here we develop FRET-based assays that report on the lateral interactions between protofilaments and find that αK40 acetylation directly weakens inter-protofilament interactions. Congruently, αK40 acetylation affects two processes largely governed by inter-protofilament interactions, reducing the nucleation frequency and accelerating the shrinkage rate. Most relevant to the biological function of acetylation, microfluidics manipulations demonstrate that αK40 acetylation enhances flexibility and confers resilience against repeated mechanical stresses. Thus, unlike deacetylated microtubules that accumulate damage when subjected to repeated stresses, long-lived microtubules are protected from mechanical ageing through their acquisition of αK40 acetylation. In contrast to other tubulin post-translational modifications that act through microtubule-associated proteins, motors and severing enzymes, intraluminal acetylation directly tunes the compliance and resilience of microtubules.
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Affiliation(s)
- Didier Portran
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, CA 94305, USA
| | - Laura Schaedel
- Laboratoire de Physiologie Cellulaire et Végétale, Institut de Recherche en Technologie et Science pour le Vivant, UMR5168, CEA/INRA/CNRS/UGA, 38054 Grenoble, France
| | - Zhenjie Xu
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, CA 94305, USA
| | - Manuel Théry
- Laboratoire de Physiologie Cellulaire et Végétale, Institut de Recherche en Technologie et Science pour le Vivant, UMR5168, CEA/INRA/CNRS/UGA, 38054 Grenoble, France
- Unité de Thérapie Cellulaire, Hôpital Saint Louis, Institut Universitaire d’Hématologie, UMRS1160, INSERM/AP-HP/Université Paris Diderot, 75010 Paris, France
| | - Maxence V. Nachury
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, CA 94305, USA
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112
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Zagni C, Floresta G, Monciino G, Rescifina A. The Search for Potent, Small-Molecule HDACIs in Cancer Treatment: A Decade After Vorinostat. Med Res Rev 2017; 37:1373-1428. [PMID: 28181261 DOI: 10.1002/med.21437] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 12/05/2016] [Accepted: 12/12/2016] [Indexed: 12/12/2022]
Abstract
Histone deacetylases (HDACs) play a crucial role in the remodeling of chromatin, and are involved in the epigenetic regulation of gene expression. In the last decade, inhibition of HDACs came out as a target for specific epigenetic changes associated with cancer and other diseases. Until now, more than 20 HDAC inhibitors (HDACIs) have entered clinical studies, and some of them (e.g., vorinostat, romidepsin) have been approved for the treatment of cutaneous T-cell lymphoma. This review provides an overview of current knowledge, progress, and molecular mechanisms of HDACIs, covering a period from 2011 until 2015.
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Affiliation(s)
- Chiara Zagni
- Dipartimento di Scienze del Farmaco, Università degli Studi di Catania, Viale Andrea Doria 6, 95125, Catania, Italy
| | - Giuseppe Floresta
- Dipartimento di Scienze del Farmaco, Università degli Studi di Catania, Viale Andrea Doria 6, 95125, Catania, Italy.,Dipartimento di Scienze Chimiche, Università degli Studi di Catania, Viale Andrea Doria 6, 95125, Catania, Italy
| | - Giulia Monciino
- Dipartimento di Scienze del Farmaco, Università degli Studi di Catania, Viale Andrea Doria 6, 95125, Catania, Italy
| | - Antonio Rescifina
- Dipartimento di Scienze del Farmaco, Università degli Studi di Catania, Viale Andrea Doria 6, 95125, Catania, Italy
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113
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Morley SJ, Qi Y, Iovino L, Andolfi L, Guo D, Kalebic N, Castaldi L, Tischer C, Portulano C, Bolasco G, Shirlekar K, Fusco CM, Asaro A, Fermani F, Sundukova M, Matti U, Reymond L, De Ninno A, Businaro L, Johnsson K, Lazzarino M, Ries J, Schwab Y, Hu J, Heppenstall PA. Acetylated tubulin is essential for touch sensation in mice. eLife 2016; 5. [PMID: 27976998 PMCID: PMC5158137 DOI: 10.7554/elife.20813] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Accepted: 11/29/2016] [Indexed: 01/11/2023] Open
Abstract
At its most fundamental level, touch sensation requires the translation of mechanical energy into mechanosensitive ion channel opening, thereby generating electro-chemical signals. Our understanding of this process, especially how the cytoskeleton influences it, remains unknown. Here we demonstrate that mice lacking the α-tubulin acetyltransferase Atat1 in sensory neurons display profound deficits in their ability to detect mechanical stimuli. We show that all cutaneous afferent subtypes, including nociceptors have strongly reduced mechanosensitivity upon Atat1 deletion, and that consequently, mice are largely insensitive to mechanical touch and pain. We establish that this broad loss of mechanosensitivity is dependent upon the acetyltransferase activity of Atat1, which when absent leads to a decrease in cellular elasticity. By mimicking α-tubulin acetylation genetically, we show both cellular rigidity and mechanosensitivity can be restored in Atat1 deficient sensory neurons. Hence, our results indicate that by influencing cellular stiffness, α-tubulin acetylation sets the force required for touch. DOI:http://dx.doi.org/10.7554/eLife.20813.001
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Affiliation(s)
- Shane J Morley
- EMBL Mouse Biology Unit, Monterotondo, Italy.,Molecular Medicine Partnership Unit (MMPU), Heidelberg, Germany
| | - Yanmei Qi
- Centre for Integrative Neuroscience, Tuebingen, Germany
| | - Loredana Iovino
- EMBL Mouse Biology Unit, Monterotondo, Italy.,Molecular Medicine Partnership Unit (MMPU), Heidelberg, Germany
| | | | - Da Guo
- Centre for Integrative Neuroscience, Tuebingen, Germany
| | - Nereo Kalebic
- EMBL Mouse Biology Unit, Monterotondo, Italy.,Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | | | | | | | | | | | | | | | | | | | - Ulf Matti
- European Molecular Biology Laboratory, Heidelberg, Germany
| | - Luc Reymond
- Ecole Polytechnique Federale de Lausanne, Lausanne, Switzerland
| | | | | | - Kai Johnsson
- Ecole Polytechnique Federale de Lausanne, Lausanne, Switzerland
| | | | - Jonas Ries
- European Molecular Biology Laboratory, Heidelberg, Germany
| | - Yannick Schwab
- European Molecular Biology Laboratory, Heidelberg, Germany
| | - Jing Hu
- Centre for Integrative Neuroscience, Tuebingen, Germany
| | - Paul A Heppenstall
- EMBL Mouse Biology Unit, Monterotondo, Italy.,Molecular Medicine Partnership Unit (MMPU), Heidelberg, Germany
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114
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Mechanism of microtubule lumen entry for the α-tubulin acetyltransferase enzyme αTAT1. Proc Natl Acad Sci U S A 2016; 113:E7176-E7184. [PMID: 27803321 DOI: 10.1073/pnas.1605397113] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Microtubules are structural polymers inside of cells that are subject to posttranslational modifications. These posttranslational modifications create functionally distinct subsets of microtubule networks in the cell, and acetylation is the only modification that takes place in the hollow lumen of the microtubule. Although it is known that the α-tubulin acetyltransferase (αTAT1) is the primary enzyme responsible for microtubule acetylation, the mechanism for how αTAT1 enters the microtubule lumen to access its acetylation sites is not well understood. By performing biochemical assays, fluorescence and electron microscopy experiments, and computational simulations, we found that αTAT1 enters the microtubule lumen through the microtubule ends, and through bends or breaks in the lattice. Thus, microtubule structure is an important determinant in the acetylation process. In addition, once αTAT1 enters the microtubule lumen, the mobility of αTAT1 within the lumen is controlled by the affinity of αTAT1 for its acetylation sites, due to the rapid rebinding of αTAT1 onto highly concentrated α-tubulin acetylation sites. These results have important implications for how acetylation could gradually accumulate on stable subsets of microtubules inside of the cell.
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115
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αTAT1 controls longitudinal spreading of acetylation marks from open microtubules extremities. Sci Rep 2016; 6:35624. [PMID: 27752143 PMCID: PMC5067677 DOI: 10.1038/srep35624] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 09/27/2016] [Indexed: 01/23/2023] Open
Abstract
Acetylation of the lysine 40 of α-tubulin (K40) is a post-translational modification occurring in the lumen of microtubules (MTs) and is controlled by the α-tubulin acetyl-transferase αTAT1. How αTAT1 accesses the lumen and acetylates α-tubulin there has been an open question. Here, we report that acetylation starts at open ends of MTs and progressively spreads longitudinally from there. We observed acetylation marks at the open ends of in vivo MTs re-growing after a Nocodazole block, and acetylated segments growing in length with time. Bias for MTs extremities was even more pronounced when using non-dynamic MTs extracted from HeLa cells. In contrast, K40 acetylation was mostly uniform along the length of MTs reconstituted from purified tubulin in vitro. Quantitative modelling of luminal diffusion of αTAT1 suggested that the uniform acetylation pattern observed in vitro is consistent with defects in the MT lattice providing lateral access to the lumen. Indeed, we observed that in vitro MTs are permeable to macromolecules along their shaft while cellular MTs are not. Our results demonstrate αTAT1 enters the lumen from open extremities and spreads K40 acetylation marks longitudinally along cellular MTs. This mode of tip-directed microtubule acetylation may allow for selective acetylation of subsets of microtubules.
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116
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Microtubule Destabilization Paves the Way to Parkinson's Disease. Mol Neurobiol 2016; 54:6762-6774. [PMID: 27757833 DOI: 10.1007/s12035-016-0188-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 09/30/2016] [Indexed: 01/20/2023]
Abstract
Microtubules are dynamic structures normally associated to the cell division, during which they form the mitotic spindle, as well as to the initial phases of specification and polarization of various cell types, including neurons. Although microtubules could have a role in the death of many cells and tissues, the microtubule-based degenerative mechanisms have been poorly investigated; nevertheless, during the last two decades, many clues have been accumulated suggesting the importance of the microtubule system during neurodegeneration. Thus, the aim of this review is to analyse how the changes of the microtubule cytoskeleton, in terms of organization and dynamics, as well as the failure of the microtubule-dependent neuronal processes, as axonal transport, may play a pivotal role in the chain of events leading to Parkinson's disease. Last but not least, since disease-modifying or neuroprotective strategies are a clinical priority in Parkinson's disease, we will also present the hints about the concrete possibility of a microtubule-targeted therapy, which would have the potentiality to block the running degenerative events and to prompt the regeneration of the lost tissues.
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117
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Galdieri L, Gatla H, Vancurova I, Vancura A. Activation of AMP-activated Protein Kinase by Metformin Induces Protein Acetylation in Prostate and Ovarian Cancer Cells. J Biol Chem 2016; 291:25154-25166. [PMID: 27733682 DOI: 10.1074/jbc.m116.742247] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 09/29/2016] [Indexed: 12/13/2022] Open
Abstract
AMP-activated protein kinase (AMPK) is an energy sensor and master regulator of metabolism. AMPK functions as a fuel gauge monitoring systemic and cellular energy status. Activation of AMPK occurs when the intracellular AMP/ATP ratio increases and leads to a metabolic switch from anabolism to catabolism. AMPK phosphorylates and inhibits acetyl-CoA carboxylase (ACC), which catalyzes carboxylation of acetyl-CoA to malonyl-CoA, the first and rate-limiting reaction in de novo synthesis of fatty acids. AMPK thus regulates homeostasis of acetyl-CoA, a key metabolite at the crossroads of metabolism, signaling, chromatin structure, and transcription. Nucleocytosolic concentration of acetyl-CoA affects histone acetylation and links metabolism and chromatin structure. Here we show that activation of AMPK with the widely used antidiabetic drug metformin or with the AMP mimetic 5-aminoimidazole-4-carboxamide ribonucleotide increases the inhibitory phosphorylation of ACC and decreases the conversion of acetyl-CoA to malonyl-CoA, leading to increased protein acetylation and altered gene expression in prostate and ovarian cancer cells. Direct inhibition of ACC with allosteric inhibitor 5-(tetradecyloxy)-2-furoic acid also increases acetylation of histones and non-histone proteins. Because AMPK activation requires liver kinase B1, metformin does not induce protein acetylation in liver kinase B1-deficient cells. Together, our data indicate that AMPK regulates the availability of nucleocytosolic acetyl-CoA for protein acetylation and that AMPK activators, such as metformin, have the capacity to increase protein acetylation and alter patterns of gene expression, further expanding the plethora of metformin's physiological effects.
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Affiliation(s)
- Luciano Galdieri
- From the Department of Biological Sciences, St. John's University, Queens, New York 11439
| | - Himavanth Gatla
- From the Department of Biological Sciences, St. John's University, Queens, New York 11439
| | - Ivana Vancurova
- From the Department of Biological Sciences, St. John's University, Queens, New York 11439
| | - Ales Vancura
- From the Department of Biological Sciences, St. John's University, Queens, New York 11439
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118
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Pagliassotti MJ, Kim PY, Estrada AL, Stewart CM, Gentile CL. Endoplasmic reticulum stress in obesity and obesity-related disorders: An expanded view. Metabolism 2016; 65:1238-46. [PMID: 27506731 PMCID: PMC4980576 DOI: 10.1016/j.metabol.2016.05.002] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 04/01/2016] [Accepted: 05/06/2016] [Indexed: 02/07/2023]
Abstract
The endoplasmic reticulum (ER) is most notable for its central roles in calcium ion storage, lipid biosynthesis, and protein sorting and processing. By virtue of its extensive membrane contact sites that connect the ER to most other organelles and to the plasma membrane, the ER can also regulate diverse cellular processes including inflammatory and insulin signaling, nutrient metabolism, and cell proliferation and death via a signaling pathway called the unfolded protein response (UPR). Chronic UPR activation has been observed in liver and/or adipose tissue of dietary and genetic murine models of obesity, and in human obesity and non-alcoholic fatty liver disease (NAFLD). Activation of the UPR in obesity and obesity-related disorders likely has two origins. One linked to classic ER stress involving the ER lumen and one linked to alterations to the ER membrane environment. This review discusses both of these origins and also considers the role of post-translational protein modifications, such as acetylation and palmitoylation, and ER-mitochondrial interactions to obesity-mediated impairments in the ER and activation of the UPR.
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Affiliation(s)
| | - Paul Y Kim
- Department of Biological Sciences, Grambling State University
| | - Andrea L Estrada
- Department of Food Science and Human Nutrition, Colorado State University
| | - Claire M Stewart
- Department of Food Science and Human Nutrition, Colorado State University
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119
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120
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Hai Y, Christianson DW. Histone deacetylase 6 structure and molecular basis of catalysis and inhibition. Nat Chem Biol 2016; 12:741-7. [PMID: 27454933 PMCID: PMC4990478 DOI: 10.1038/nchembio.2134] [Citation(s) in RCA: 315] [Impact Index Per Article: 39.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 04/11/2016] [Indexed: 12/11/2022]
Abstract
Histone deacetylase 6 (HDAC6) is a critical target for drug design due to its role in oncogenic transformation and cancer metastasis, and is unique among all histone deacetylases in that it contains tandem catalytic domains designated CD1 and CD2. We now report the crystal structures of CD2 from Homo sapiens and CD1 and CD2 from Danio rerio HDAC6, and we correlate these structures with activity measurements using a panel of 13 different substrates. The catalytic activity of CD2 from both species exhibits broad substrate specificity, whereas that of CD1 is highly specific for substrates bearing C-terminal acetyllysine residues. Crystal structures of substrate complexes yield unprecedented snapshots of the catalytic mechanism. Additionally, crystal structures of complexes with 8 different inhibitors, including Belinostat and Panobinostat (currently used in cancer chemotherapy), the macrocyclic tetrapeptide HC toxin, and the HDAC6-specific inhibitor N-hydroxy-4-(2-[(2-hydroxyethyl)(phenyl)amino]-2-oxoethyl)benzamide, reveal surprising new insight regarding changes in Zn2+ coordination and isozyme-specific inhibition.
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Affiliation(s)
- Yang Hai
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - David W Christianson
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Radcliffe Institute for Advanced Study and Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, USA
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121
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Structural insights into HDAC6 tubulin deacetylation and its selective inhibition. Nat Chem Biol 2016; 12:748-54. [DOI: 10.1038/nchembio.2140] [Citation(s) in RCA: 181] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 06/22/2016] [Indexed: 12/31/2022]
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122
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The growing landscape of tubulin acetylation: lysine 40 and many more. Biochem J 2016; 473:1859-68. [DOI: 10.1042/bcj20160172] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 03/29/2016] [Indexed: 11/17/2022]
Abstract
Tubulin heterodimers are the building block of microtubules, which are major elements of the cytoskeleton. Several types of post-translational modifications are found on tubulin subunits as well as on the microtubule polymer to regulate the multiple roles of microtubules. Acetylation of lysine 40 (K40) of the α-tubulin subunit is one of these post-translational modifications which has been extensively studied. We summarize the current knowledge about the structural aspects of K40 acetylation, the functional consequences, the enzymes involved and their regulation. Most importantly, we discuss the potential importance of the recently discovered additional acetylation acceptor lysines in tubulin subunits and highlight the urgent need to study tubulin acetylation in a more integrated perspective.
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123
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Barisic M, Maiato H. The Tubulin Code: A Navigation System for Chromosomes during Mitosis. Trends Cell Biol 2016; 26:766-775. [PMID: 27344407 DOI: 10.1016/j.tcb.2016.06.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 05/27/2016] [Accepted: 06/02/2016] [Indexed: 10/25/2022]
Abstract
Before chromosomes segregate during mitosis in metazoans, they align at the cell equator by a process known as chromosome congression. This is in part mediated by the coordinated activities of kinetochore motors with opposite directional preferences that transport peripheral chromosomes along distinct spindle microtubule populations. Because spindle microtubules are all made from the same α/β-tubulin heterodimers, a critical longstanding question has been how chromosomes are guided to specific locations during mitosis. This implies the existence of spatial cues/signals on specific spindle microtubules that are read by kinetochore motors on chromosomes and ultimately indicate the way towards the equator. Here, we discuss the emerging concept that tubulin post-translational modifications (PTMs), as part of the so-called tubulin code, work as a navigation system for kinetochore-based chromosome motility during early mitosis.
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Affiliation(s)
- Marin Barisic
- Danish Cancer Society Research Center, Cell Division Laboratory, Strandboulevarden 49, 2100 Copenhagen, Denmark.
| | - Helder Maiato
- Chromosome Instability and Dynamics Laboratory, Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; Instituto de Investigação e Inovação em Saúde - i3S, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; Cell Division Unit, Department of Experimental Biology, Faculdade de Medicina, Universidade do Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal.
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124
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Skoge RH, Ziegler M. SIRT2 inactivation reveals a subset of hyperacetylated perinuclear microtubules inaccessible to HDAC6. J Cell Sci 2016; 129:2972-82. [PMID: 27311481 DOI: 10.1242/jcs.187518] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 06/10/2016] [Indexed: 01/07/2023] Open
Abstract
Deacetylation of α-tubulin at lysine 40 is catalyzed by two enzymes, the NAD-dependent deacetylase SIRT2 and the NAD-independent deacetylase HDAC6, in apparently redundant reactions. In the present study, we tested whether these two enzymes might have distinguishable preferences for the deacetylation of different microtubule structures. Using various agents, we induced tubulin hyperacetylation and analyzed the ensuing formation of distinct microtubule structures. HDAC6 inhibition led to general hyperacetylation of the microtubule network throughout the cell, whereas hyperacetylation induced by SIRT2 inactivation was limited to perinuclear microtubules. Hyperacetylation of these perinuclear microtubules was undiminished following HDAC6 overexpression, whereas reactivation of SIRT2 restored the basal acetylation level and a normal microtubule network. By contrast, SIRT2 and HDAC6 acted similarly on the morphologically different, hyperacetylated microtubule structures induced by taxol, MAP2c overexpression or hyperosmotic stress. These results indicate overlapping and distinct functions of HDAC6 and SIRT2. We propose that the differential activity of the two deacetylases, which target the same acetylated lysine residue, might be related to the recognition of specific structural contexts.
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Affiliation(s)
- Renate Hvidsten Skoge
- Department of Molecular Biology, University of Bergen, Postbox 7803, Bergen 5020, Norway
| | - Mathias Ziegler
- Department of Molecular Biology, University of Bergen, Postbox 7803, Bergen 5020, Norway
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125
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Yu J, Ma Z, Shetty S, Ma M, Fu J. Selective HDAC6 inhibition prevents TNF-α-induced lung endothelial cell barrier disruption and endotoxin-induced pulmonary edema. Am J Physiol Lung Cell Mol Physiol 2016; 311:L39-47. [PMID: 27190059 DOI: 10.1152/ajplung.00051.2016] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 05/17/2016] [Indexed: 12/16/2022] Open
Abstract
Lung endothelial damage contributes to the pathogenesis of acute lung injury. New strategies against lung endothelial barrier dysfunction may provide therapeutic benefits against lung vascular injury. Cell-cell junctions and microtubule cytoskeleton are basic components in maintaining endothelial barrier integrity. HDAC6, a deacetylase primarily localized in the cytoplasm, has been reported to modulate nonnuclear protein function through deacetylation. Both α-tubulin and β-catenin are substrates for HDAC6. Here, we examined the effects of tubastatin A, a highly selective HDAC6 inhibitor, on TNF-α induced lung endothelial cell barrier disruption and endotoxin-induced pulmonary edema. Selective HDAC6 inhibition by tubastatin A blocked TNF-α-induced lung endothelial cell hyperpermeability, which was associated with increased α-tubulin acetylation and microtubule stability. Tubastatin A pretreatment inhibited TNF-α-induced endothelial cell contraction and actin stress fiber formation with reduced myosin light chain phosphorylation. Selective HDAC6 inhibition by tubastatin A also induced β-catenin acetylation in human lung endothelial cells, which was associated with increased membrane localization of β-catenin and stabilization of adherens junctions. HDAC6 knockdown by small interfering RNA also prevented TNF-α-induced barrier dysfunction and increased α-tubulin and β-catenin acetylation in endothelial cells. Furthermore, in a mouse model of endotoxemia, tubastatin A was able to prevent endotoxin-induced deacetylation of α-tubulin and β-catenin in lung tissues, which was associated with reduced pulmonary edema. Collectively, our data indicate that selective HDAC6 inhibition by tubastatin A is a potent approach against lung endothelial barrier dysfunction.
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Affiliation(s)
- Jinyan Yu
- The Second Hospital of Jilin University, Jilin, China; Center for Research on Environmental Disease, College of Medicine, University of Kentucky, Lexington, Kentucky; Department of Toxicology and Cancer Biology, College of Medicine, University of Kentucky, Lexington, Kentucky; and
| | - Zhongsen Ma
- The Second Hospital of Jilin University, Jilin, China
| | - Sreerama Shetty
- Center for Biomedical Research, University of Texas Health Science Center, Tyler, Texas
| | - Mengshi Ma
- The Second Hospital of Jilin University, Jilin, China; Center for Research on Environmental Disease, College of Medicine, University of Kentucky, Lexington, Kentucky
| | - Jian Fu
- Center for Research on Environmental Disease, College of Medicine, University of Kentucky, Lexington, Kentucky; Department of Toxicology and Cancer Biology, College of Medicine, University of Kentucky, Lexington, Kentucky; and
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126
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Chakraborti S, Natarajan K, Curiel J, Janke C, Liu J. The emerging role of the tubulin code: From the tubulin molecule to neuronal function and disease. Cytoskeleton (Hoboken) 2016; 73:521-550. [PMID: 26934450 DOI: 10.1002/cm.21290] [Citation(s) in RCA: 102] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 02/18/2016] [Accepted: 02/26/2016] [Indexed: 11/11/2022]
Abstract
Across different cell types and tissues, microtubules are assembled from highly conserved dimers of α- and β-tubulin. Despite their highly similar structures, microtubules have functional heterogeneity, generated either by the expression of different tubulin genes, encoding distinct isotypes, or by posttranslational modifications of tubulin. This genetically encoded and posttranslational generated heterogeneity of tubulin-the "tubulin code"-has the potential to modulate microtubule structure, dynamics, and interactions with associated proteins. The tubulin code is therefore believed to regulate microtubule functions on a cellular and sub-cellular level. This review highlights the importance of the tubulin code for tubulin structure, as well as on microtubule dynamics and functions in neurons. It further summarizes recent developments in the understanding of mutations in tubulin genes, and how they are linked to neurodegenerative and neurodevelopmental disorders. The current advances in the knowledge of the tubulin code on the molecular and the functional level will certainly lead to a better understanding of how complex signaling events control microtubule functions, especially in cells of the nervous system. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Soumyananda Chakraborti
- Institut Curie, PSL Research University, CNRS, INSERM, UMR 3348, Orsay, F-91405, France.,Université Paris Sud, Université Paris-Saclay, CNRS, UMR 3348, Orsay, F-91405, France
| | - Kathiresan Natarajan
- Institut Curie, PSL Research University, CNRS, INSERM, UMR 3348, Orsay, F-91405, France.,Université Paris Sud, Université Paris-Saclay, CNRS, UMR 3348, Orsay, F-91405, France
| | - Julian Curiel
- Children's National Health System, Center for Neuroscience Research, Washington, District of Columbia
| | - Carsten Janke
- Institut Curie, PSL Research University, CNRS, INSERM, UMR 3348, Orsay, F-91405, France. .,Université Paris Sud, Université Paris-Saclay, CNRS, UMR 3348, Orsay, F-91405, France.
| | - Judy Liu
- Children's National Health System, Center for Neuroscience Research, Washington, District of Columbia.
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127
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Liang Y, Meng D, Zhu B, Pan J. Mechanism of ciliary disassembly. Cell Mol Life Sci 2016; 73:1787-802. [PMID: 26869233 PMCID: PMC11108551 DOI: 10.1007/s00018-016-2148-7] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 01/22/2016] [Accepted: 01/25/2016] [Indexed: 12/19/2022]
Abstract
As motile organelles and sensors, cilia play pivotal roles in cell physiology, development and organ homeostasis. Ciliary defects are associated with a class of cilia-related diseases or developmental disorders, termed ciliopathies. Even though the presence of cilia is required for diverse functions, cilia can be removed through ciliary shortening or resorption that necessitates disassembly of the cilium, which occurs normally during cell cycle progression, cell differentiation and in response to cellular stress. The functional significance of ciliary resorption is highlighted in controlling the G1-S transition during cell cycle progression. Internal or external cues that trigger ciliary resorption initiate signaling cascades that regulate several downstream events including depolymerization of axonemal microtubules, dynamic changes in actin and the ciliary membrane, regulation of intraflagellar transport and posttranslational modifications of ciliary proteins. To ensure ciliary resorption, both the active disassembly of the cilium and the simultaneous inhibition of ciliary assembly must be coordinately regulated.
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Affiliation(s)
- Yinwen Liang
- MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Dan Meng
- MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Bing Zhu
- MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Junmin Pan
- MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong, China.
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128
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Vemu A, Atherton J, Spector JO, Szyk A, Moores CA, Roll-Mecak A. Structure and Dynamics of Single-isoform Recombinant Neuronal Human Tubulin. J Biol Chem 2016; 291:12907-15. [PMID: 27129203 PMCID: PMC4933209 DOI: 10.1074/jbc.c116.731133] [Citation(s) in RCA: 96] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Indexed: 12/31/2022] Open
Abstract
Microtubules are polymers that cycle stochastically between polymerization and depolymerization, i.e. they exhibit "dynamic instability." This behavior is crucial for cell division, motility, and differentiation. Although studies in the last decade have made fundamental breakthroughs in our understanding of how cellular effectors modulate microtubule dynamics, analysis of the relationship between tubulin sequence, structure, and dynamics has been held back by a lack of dynamics measurements with and structural characterization of homogeneous isotypically pure engineered tubulin. Here, we report for the first time the cryo-EM structure and in vitro dynamics parameters of recombinant isotypically pure human tubulin. α1A/βIII is a purely neuronal tubulin isoform. The 4.2-Å structure of post-translationally unmodified human α1A/βIII microtubules shows overall similarity to that of heterogeneous brain microtubules, but it is distinguished by subtle differences at polymerization interfaces, which are hot spots for sequence divergence between tubulin isoforms. In vitro dynamics assays show that, like mosaic brain microtubules, recombinant homogeneous microtubules undergo dynamic instability, but they polymerize slower and have fewer catastrophes. Interestingly, we find that epitaxial growth of α1A/βIII microtubules from heterogeneous brain seeds is inefficient but can be fully rescued by incorporating as little as 5% of brain tubulin into the homogeneous α1A/βIII lattice. Our study establishes a system to examine the structure and dynamics of mammalian microtubules with well defined tubulin species and is a first and necessary step toward uncovering how tubulin genetic and chemical diversity is exploited to modulate intrinsic microtubule dynamics.
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Affiliation(s)
| | - Joseph Atherton
- the Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck College, University of London, London WC1E, United Kingdom
| | | | | | - Carolyn A Moores
- the Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck College, University of London, London WC1E, United Kingdom
| | - Antonina Roll-Mecak
- From the Cell Biology and Biophysics Unit, NINDS, and Biophysics Center, NHLBI, National Institutes of Health, Bethesda, Maryland 20892 and
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129
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Alonso VL, Ritagliati C, Cribb P, Cricco JA, Serra EC. Overexpression of bromodomain factor 3 inTrypanosoma cruzi(TcBDF3) affects differentiation of the parasite and protects it against bromodomain inhibitors. FEBS J 2016; 283:2051-66. [DOI: 10.1111/febs.13719] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2015] [Revised: 02/16/2016] [Accepted: 03/22/2016] [Indexed: 12/01/2022]
Affiliation(s)
- Victoria Lucia Alonso
- Facultad de Ciencias Bioquímicas y Farmacéuticas; Universidad Nacional de Rosario; Argentina
| | - Carla Ritagliati
- Instituto de Biología Molecular y Celular de Rosario (IBR); CONICET; Rosario Argentina
| | - Pamela Cribb
- Facultad de Ciencias Bioquímicas y Farmacéuticas; Universidad Nacional de Rosario; Argentina
- Instituto de Biología Molecular y Celular de Rosario (IBR); CONICET; Rosario Argentina
| | - Julia Alejandra Cricco
- Facultad de Ciencias Bioquímicas y Farmacéuticas; Universidad Nacional de Rosario; Argentina
- Instituto de Biología Molecular y Celular de Rosario (IBR); CONICET; Rosario Argentina
| | - Esteban Carlos Serra
- Facultad de Ciencias Bioquímicas y Farmacéuticas; Universidad Nacional de Rosario; Argentina
- Instituto de Biología Molecular y Celular de Rosario (IBR); CONICET; Rosario Argentina
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130
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Zhang DX, Zhang JP, Hu JY, Huang YS. The potential regulatory roles of NAD(+) and its metabolism in autophagy. Metabolism 2016; 65:454-62. [PMID: 26975537 DOI: 10.1016/j.metabol.2015.11.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 10/29/2015] [Accepted: 11/25/2015] [Indexed: 02/02/2023]
Abstract
(Macro)autophagy mediates the bulk degradation of defective organelles, long-lived proteins and protein aggregates in lysosomes and plays a critical role in cellular and tissue homeostasis. Defective autophagy processes have been found to contribute to a variety of metabolic diseases. However, the regulatory mechanisms of autophagy are not fully understood. Increasing data indicate that nicotinamide adenine nucleotide (NAD(+)) homeostasis correlates intimately with autophagy. NAD(+) is a ubiquitous coenzyme that functions primarily as an electron carrier of oxidoreductase in multiple redox reactions. Both NAD(+) homeostasis and its metabolism are thought to play critical roles in regulating autophagy. In this review, we discuss how the regulation of NAD(+) and its metabolism can influence autophagy. We focus on the regulation of NAD(+)/NADH homeostasis and the effects of NAD(+) consumption by poly(ADP-ribose) (PAR) polymerase-1 (PARP-1), NAD(+)-dependent deacetylation by sirtuins and NAD(+) metabolites on autophagy processes and the underlying mechanisms. Future studies should provide more direct evidence for the regulation of autophagy processes by NAD(+). A better understanding of the critical roles of NAD(+) and its metabolites on autophagy will shed light on the complexity of autophagy regulation, which is essential for the discovery of new therapeutic tools for autophagy-related diseases.
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Affiliation(s)
- Dong-Xia Zhang
- Institute of Burn Research, Southwest Hospital, Third Military Medical University, State Key Laboratory of Trauma, Burns and Combined Injury, Chongqing, PR China, 400038
| | - Jia-Ping Zhang
- Institute of Burn Research, Southwest Hospital, Third Military Medical University, State Key Laboratory of Trauma, Burns and Combined Injury, Chongqing, PR China, 400038
| | - Jiong-Yu Hu
- Endocrinology Department, Southwest Hospital, State Key Laboratory of Trauma, Burns and Combined Injury, Third Military Medical University, Chongqing, PR China, 400038
| | - Yue-Sheng Huang
- Institute of Burn Research, Southwest Hospital, Third Military Medical University, State Key Laboratory of Trauma, Burns and Combined Injury, Chongqing, PR China, 400038.
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131
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Hotta T, Fujita S, Uchimura S, Noguchi M, Demura T, Muto E, Hashimoto T. Affinity Purification and Characterization of Functional Tubulin from Cell Suspension Cultures of Arabidopsis and Tobacco. PLANT PHYSIOLOGY 2016; 170:1189-205. [PMID: 26747285 PMCID: PMC4775104 DOI: 10.1104/pp.15.01173] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 12/29/2015] [Indexed: 05/02/2023]
Abstract
Microtubules assemble into several distinct arrays that play important roles in cell division and cell morphogenesis. To decipher the mechanisms that regulate the dynamics and organization of this versatile cytoskeletal component, it is essential to establish in vitro assays that use functional tubulin. Although plant tubulin has been purified previously from protoplasts by reversible taxol-induced polymerization, a simple and efficient purification method has yet to be developed. Here, we used a Tumor Overexpressed Gene (TOG) column, in which the tubulin-binding domains of a yeast (Saccharomyces cerevisiae) TOG homolog are immobilized on resin, to isolate functional plant tubulin. We found that several hundred micrograms of pure tubulin can readily be purified from cell suspension cultures of tobacco (Nicotiana tabacum) and Arabidopsis (Arabidopsis thaliana). The tubulin purified by the TOG column showed high assembly competence, partly because of low levels of polymerization-inhibitory phosphorylation of α-tubulin. Compared with porcine brain tubulin, Arabidopsis tubulin is highly dynamic in vitro at both the plus and minus ends, exhibiting faster shrinkage rates and more frequent catastrophe events, and exhibits frequent spontaneous nucleation. Furthermore, our study shows that an internal histidine tag in α-tubulin can be used to prepare particular isotypes and specifically engineered versions of α-tubulin. In contrast to previous studies of plant tubulin, our mass spectrometry and immunoblot analyses failed to detect posttranslational modification of the isolated Arabidopsis tubulin or detected only low levels of posttranslational modification. This novel technology can be used to prepare assembly-competent, highly dynamic pure tubulin from plant cell cultures.
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Affiliation(s)
- Takashi Hotta
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan (T.Ho., S.F., M.N., T.D., T.Ha.); andLaboratory of Molecular Biophysics, RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan (S.U., E.M.)
| | - Satoshi Fujita
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan (T.Ho., S.F., M.N., T.D., T.Ha.); andLaboratory of Molecular Biophysics, RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan (S.U., E.M.)
| | - Seiichi Uchimura
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan (T.Ho., S.F., M.N., T.D., T.Ha.); andLaboratory of Molecular Biophysics, RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan (S.U., E.M.)
| | - Masahiro Noguchi
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan (T.Ho., S.F., M.N., T.D., T.Ha.); andLaboratory of Molecular Biophysics, RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan (S.U., E.M.)
| | - Taku Demura
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan (T.Ho., S.F., M.N., T.D., T.Ha.); andLaboratory of Molecular Biophysics, RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan (S.U., E.M.)
| | - Etsuko Muto
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan (T.Ho., S.F., M.N., T.D., T.Ha.); andLaboratory of Molecular Biophysics, RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan (S.U., E.M.)
| | - Takashi Hashimoto
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan (T.Ho., S.F., M.N., T.D., T.Ha.); andLaboratory of Molecular Biophysics, RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan (S.U., E.M.)
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132
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He Z, Wu J, Su X, Zhang Y, Pan L, Wei H, Fang Q, Li H, Wang DL, Sun FL. JMJD5 (Jumonji Domain-containing 5) Associates with Spindle Microtubules and Is Required for Proper Mitosis. J Biol Chem 2016; 291:4684-97. [PMID: 26710852 PMCID: PMC4813491 DOI: 10.1074/jbc.m115.672642] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 12/17/2015] [Indexed: 11/06/2022] Open
Abstract
Precise mitotic spindle assembly is a guarantee of proper chromosome segregation during mitosis. Chromosome instability caused by disturbed mitosis is one of the major features of various types of cancer. JMJD5 has been reported to be involved in epigenetic regulation of gene expression in the nucleus, but little is known about its function in mitotic process. Here we report the unexpected localization and function of JMJD5 in mitotic progression. JMJD5 partially accumulates on mitotic spindles during mitosis, and depletion of JMJD5 results in significant mitotic arrest, spindle assembly defects, and sustained activation of the spindle assembly checkpoint (SAC). Inactivating SAC can efficiently reverse the mitotic arrest caused by JMJD5 depletion. Moreover, JMJD5 is found to interact with tubulin proteins and associate with microtubules during mitosis. JMJD5-depleted cells show a significant reduction of α-tubulin acetylation level on mitotic spindles and fail to generate enough interkinetochore tension to satisfy the SAC. Further, JMJD5 depletion also increases the susceptibility of HeLa cells to the antimicrotubule agent. Taken together, these results suggest that JMJD5 plays an important role in regulating mitotic progression, probably by modulating the stability of spindle microtubules.
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Affiliation(s)
- Zhimin He
- From the Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China and
| | - Junyu Wu
- From the Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China and
| | - Xiaonan Su
- From the Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China and
| | - Ye Zhang
- From the Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China and
| | - Lixia Pan
- From the Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China and
| | - Huimin Wei
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200092/200120, China
| | - Qiang Fang
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200092/200120, China
| | - Haitao Li
- From the Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China and
| | - Da-Liang Wang
- From the Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China and
| | - Fang-Lin Sun
- From the Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China and Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200092/200120, China
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133
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Valenstein ML, Roll-Mecak A. Graded Control of Microtubule Severing by Tubulin Glutamylation. Cell 2016; 164:911-21. [PMID: 26875866 DOI: 10.1016/j.cell.2016.01.019] [Citation(s) in RCA: 193] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 11/17/2015] [Accepted: 01/13/2016] [Indexed: 10/22/2022]
Abstract
Microtubule-severing enzymes are critical for the biogenesis and maintenance of complex microtubule arrays in axons, spindles, and cilia where tubulin detyrosination, acetylation, and glutamylation are abundant. These modifications exhibit stereotyped patterns suggesting spatial and temporal control of microtubule functions. Using human-engineered and differentially modified microtubules we find that glutamylation is the main regulator of the hereditary spastic paraplegia microtubule severing enzyme spastin. Glutamylation acts as a rheostat and tunes microtubule severing as a function of glutamate number added per tubulin. Unexpectedly, glutamylation is a non-linear biphasic tuner and becomes inhibitory beyond a threshold. Furthermore, the inhibitory effect of localized glutamylation propagates across neighboring microtubules, modulating severing in trans. Our work provides the first quantitative evidence for a graded response to a tubulin posttranslational modification and a biochemical link between tubulin glutamylation and complex architectures of microtubule arrays such as those in neurons where spastin deficiency causes disease.
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Affiliation(s)
- Max L Valenstein
- Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA
| | - Antonina Roll-Mecak
- Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA; National Heart, Lung and Blood Institute, Bethesda, MD 20892, USA.
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134
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Dhital B, Labadie C, Stallmach F, Möller HE, Turner R. Temperature dependence of water diffusion pools in brain white matter. Neuroimage 2016; 127:135-143. [DOI: 10.1016/j.neuroimage.2015.11.064] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Revised: 11/15/2015] [Accepted: 11/25/2015] [Indexed: 10/22/2022] Open
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135
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Nogales E, Zhang R. Visualizing microtubule structural transitions and interactions with associated proteins. Curr Opin Struct Biol 2016; 37:90-6. [PMID: 26803284 DOI: 10.1016/j.sbi.2015.12.009] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 12/14/2015] [Accepted: 12/28/2015] [Indexed: 11/25/2022]
Abstract
Microtubules (MTs) have been the subject of cryo-electron microscopy (cryo-EM) studies since the birth of this technique. Although MTs pose some unique challenges, having to do with the presence of a MT seam, lattice variability and disorder, MT cryo-EM reconstructions are steadily improving in resolution and providing exciting new insights into MT structure and function. Recent work has lead to the atomic-detail visualization of lateral contacts between tubulin subunits and the conformational changes that give rise to strain in the MT lattice accompanying GTP hydrolysis. Cryo-EM has also been invaluable in describing the interactions between MTs and MT associated proteins (MAPs), which function to regulate MT dynamic instability, move cargoes, or contribute to other MT cellular processes.
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Affiliation(s)
- Eva Nogales
- Molecular and Cell Biology Department and QB3 Institute, UC Berkeley, CA 94720, United States; Howard Hughes Medical Institute, UC Berkeley, CA 94720, United States; Molecular Biophysics and Integrative Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States.
| | - Rui Zhang
- Howard Hughes Medical Institute, UC Berkeley, CA 94720, United States; Molecular Biophysics and Integrative Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States
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136
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TgATAT-Mediated α-Tubulin Acetylation Is Required for Division of the Protozoan Parasite Toxoplasma gondii. mSphere 2016; 1:mSphere00088-15. [PMID: 27303695 PMCID: PMC4863603 DOI: 10.1128/msphere.00088-15] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 01/05/2016] [Indexed: 01/05/2023] Open
Abstract
Toxoplasma gondii is an opportunistic parasite that infects at least one-third of the world population. New treatments for the disease (toxoplasmosis) are needed since current drugs are toxic to patients. Microtubules are essential cellular structures built from tubulin that show promise as antimicrobial drug targets. Microtubules can be regulated by chemical modification, such as acetylation on lysine 40 (K40). To determine the role of K40 acetylation in Toxoplasma and whether it is a liability to the parasite, we performed mutational analyses of the α-tubulin gene. Our results indicate that parasites cannot survive without K40 acetylation unless microtubules are stabilized with a secondary mutation. Additionally, we identified the parasite enzyme that acetylates α-tubulin (TgATAT). Genetic disruption of TgATAT caused severe defects in parasite replication, further highlighting the importance of α-tubulin K40 acetylation in Toxoplasma and its promise as a potential new drug target. Toxoplasma gondii is a widespread protozoan parasite that causes potentially life-threatening opportunistic disease. New inhibitors of parasite replication are urgently needed, as the current antifolate treatment is also toxic to patients. Microtubules are essential cytoskeletal components that have been selectively targeted in microbial pathogens; further study of tubulin in Toxoplasma may reveal novel therapeutic opportunities. It has been noted that α-tubulin acetylation at lysine 40 (K40) is enriched during daughter parasite formation, but the impact of this modification on Toxoplasma division and the enzyme mediating its delivery have not been identified. We performed mutational analyses to provide evidence that K40 acetylation stabilizes Toxoplasma microtubules and is required for parasite replication. We also show that an unusual Toxoplasma homologue of α-tubulin acetyltransferase (TgATAT) is expressed in a cell cycle-regulated manner and that its expression peaks during division. Disruption of TgATAT with CRISPR/Cas9 ablates K40 acetylation and induces replication defects; parasites appear to initiate mitosis yet exhibit incomplete or improper nuclear division. Together, these findings establish the importance of tubulin acetylation, exposing a new vulnerability in Toxoplasma that could be pharmacologically targeted. IMPORTANCEToxoplasma gondii is an opportunistic parasite that infects at least one-third of the world population. New treatments for the disease (toxoplasmosis) are needed since current drugs are toxic to patients. Microtubules are essential cellular structures built from tubulin that show promise as antimicrobial drug targets. Microtubules can be regulated by chemical modification, such as acetylation on lysine 40 (K40). To determine the role of K40 acetylation in Toxoplasma and whether it is a liability to the parasite, we performed mutational analyses of the α-tubulin gene. Our results indicate that parasites cannot survive without K40 acetylation unless microtubules are stabilized with a secondary mutation. Additionally, we identified the parasite enzyme that acetylates α-tubulin (TgATAT). Genetic disruption of TgATAT caused severe defects in parasite replication, further highlighting the importance of α-tubulin K40 acetylation in Toxoplasma and its promise as a potential new drug target.
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137
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Shen B, He Y, Kim Y, Wang Y, Lee M. Spontaneous Capture of Carbohydrate Guests through Folding and Zipping of Self-Assembled Ribbons. Angew Chem Int Ed Engl 2016; 55:2382-6. [DOI: 10.1002/anie.201509190] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 11/22/2015] [Indexed: 11/06/2022]
Affiliation(s)
- Bowen Shen
- State Key Laboratory of Supramolecular Structure and Materials; College of Chemistry; Jilin University; Changchun 130012 China
| | - Ying He
- State Key Laboratory of Supramolecular Structure and Materials; College of Chemistry; Jilin University; Changchun 130012 China
| | - Yongju Kim
- State Key Laboratory of Supramolecular Structure and Materials; College of Chemistry; Jilin University; Changchun 130012 China
| | - Yanqiu Wang
- State Key Laboratory of Supramolecular Structure and Materials; College of Chemistry; Jilin University; Changchun 130012 China
| | - Myongsoo Lee
- State Key Laboratory of Supramolecular Structure and Materials; College of Chemistry; Jilin University; Changchun 130012 China
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138
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Shen B, He Y, Kim Y, Wang Y, Lee M. Spontaneous Capture of Carbohydrate Guests through Folding and Zipping of Self-Assembled Ribbons. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201509190] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Bowen Shen
- State Key Laboratory of Supramolecular Structure and Materials; College of Chemistry; Jilin University; Changchun 130012 China
| | - Ying He
- State Key Laboratory of Supramolecular Structure and Materials; College of Chemistry; Jilin University; Changchun 130012 China
| | - Yongju Kim
- State Key Laboratory of Supramolecular Structure and Materials; College of Chemistry; Jilin University; Changchun 130012 China
| | - Yanqiu Wang
- State Key Laboratory of Supramolecular Structure and Materials; College of Chemistry; Jilin University; Changchun 130012 China
| | - Myongsoo Lee
- State Key Laboratory of Supramolecular Structure and Materials; College of Chemistry; Jilin University; Changchun 130012 China
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139
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Li X, Guo Y, Yao Y, Hua J, Ma Y, Liu C, Guan W. Reversine Increases the Plasticity of Long-Term Cryopreserved Fibroblasts to Multipotent Progenitor Cells through Activation of Oct4. Int J Biol Sci 2016; 12:53-62. [PMID: 26722217 PMCID: PMC4679398 DOI: 10.7150/ijbs.12199] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Accepted: 09/23/2015] [Indexed: 12/28/2022] Open
Abstract
Reversine, a purine analog, had been evidenced that it could induce dedifferentiation of differentiated cells into multipotent progenitor cells. Here, we showed that reversine could increase the plasticity of long-term cryopreserved bovine fibroblasts, and reversine-treated cells achieved the ability to differentiate into all three germ layers cells, such as osteoblasts and adipocytes from mesoblast, neurocyte from ectoderm, hepatocytes and smooth muscle cells from endoderm. Moreover, treatment of reversine caused the grow arrest of fibroblasts at G2/M and distinct cell swelling resulting in the formation of polyploid cells. In parallel, reversine treatment induced a multipotency of fibroblasts might be attributed to the activation of histone modifications, especially the degression of DNA methylation. However, molecular and cellular experiments suggested that reversine treatment enhanced selectively the expression of pluripotent marker gene Oct4 and mesenchymal marker genes CD29, CD44 and CD73, but Sox2 and Nanog were not detected. Taken together, these results clearly demonstrate the ability of reversine to dedifferentiation of long-term cryopreserved somatic cells through activation of pluripotent gene Oct4.
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Affiliation(s)
- Xiangchen Li
- 1. Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Yu Guo
- 1. Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China. ; 2. Department of Bioscience, Department of laboratory medicine, Bengbu Medical College, Bengbu 233000, China
| | - Yaxin Yao
- 1. Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Jinlian Hua
- 3. Key Lab for Animal Biotechnology of Agriculture Ministry of China, Northwest A & F University, Yangling, 712100, China
| | - Yuehui Ma
- 1. Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Changqing Liu
- 1. Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China. ; 2. Department of Bioscience, Department of laboratory medicine, Bengbu Medical College, Bengbu 233000, China
| | - Weijun Guan
- 1. Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
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140
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Gartz Hanson M, Aiken J, Sietsema DV, Sept D, Bates EA, Niswander L, Moore JK. Novel α-tubulin mutation disrupts neural development and tubulin proteostasis. Dev Biol 2015; 409:406-19. [PMID: 26658218 DOI: 10.1016/j.ydbio.2015.11.022] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 11/10/2015] [Accepted: 11/27/2015] [Indexed: 10/22/2022]
Abstract
Mutations in the microtubule cytoskeleton are linked to cognitive and locomotor defects during development, and neurodegeneration in adults. How these mutations impact microtubules, and how this alters function at the level of neurons is an important area of investigation. Using a forward genetic screen in mice, we identified a missense mutation in Tuba1a α-tubulin that disrupts cortical and motor neuron development. Homozygous mutant mice exhibit cortical dysgenesis reminiscent of human tubulinopathies. Motor neurons fail to innervate target muscles in the limbs and show synapse defects at proximal targets. To directly examine effects on tubulin function, we created analogous mutations in the α-tubulin isotypes in budding yeast. These mutations sensitize yeast cells to microtubule stresses including depolymerizing drugs and low temperatures. Furthermore, we find that mutant α-tubulin is depleted from the cell lysate and from microtubules, thereby altering ratios of α-tubulin isotypes. Tubulin-binding cofactors suppress the effects of the mutation, indicating an important role for these cofactors in regulating the quality of the α-tubulin pool. Together, our results give new insights into the functions of Tuba1a, mechanisms for regulating tubulin proteostasis, and how compromising these may lead to neural defects.
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Affiliation(s)
- M Gartz Hanson
- Department of Pediatrics, University of Colorado, Anschutz Medical Campus, Aurora, CO, USA
| | - Jayne Aiken
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Daniel V Sietsema
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO, USA
| | - David Sept
- Department of Biomedical Engineering and Center for Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Emily A Bates
- Department of Pediatrics, University of Colorado, Anschutz Medical Campus, Aurora, CO, USA
| | - Lee Niswander
- Department of Pediatrics, University of Colorado, Anschutz Medical Campus, Aurora, CO, USA
| | - Jeffrey K Moore
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO, USA.
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141
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Abstract
We investigate single file diffusion (SFD) of large particles entering a semi-infinite tube, such as luminal diffusion of proteins into microtubules or flagella. While single-file effects have no impact on the evolution of particle density, we report significant single-file effects for individually tracked tracer particle motion. Both exact and approximate ordering statistics of particles entering semi-infinite tubes agree well with our stochastic simulations. Considering initially empty semi-infinite tubes, with particles entering at one end starting from an initial time t = 0, tracked particles are initially super-diffusive after entering the system, but asymptotically diffusive at later times. For finite time intervals, the ratio of the net displacement of individual single-file particles to the average displacement of untracked particles is reduced at early times and enhanced at later times. When each particle is numbered, from the first to enter (n = 1) to the most recent (n = N), we find good scaling collapse of this distance ratio for all n. Experimental techniques that track individual particles, or local groups of particles, such as photo-activation or photobleaching of fluorescently tagged proteins, should be able to observe these single-file effects. However, biological phenomena that depend on local concentration, such as flagellar extension or luminal enzymatic activity, should not exhibit single-file effects.
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Affiliation(s)
- Spencer G Farrell
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, NS, B3H 4R2, Canada
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142
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Li W, Mukherjee A, Wu J, Zhang L, Teves ME, Li H, Nambiar S, Henderson SC, Horwitz AR, Strauss JF, Fang X, Zhang Z. Sperm Associated Antigen 6 (SPAG6) Regulates Fibroblast Cell Growth, Morphology, Migration and Ciliogenesis. Sci Rep 2015; 5:16506. [PMID: 26585507 PMCID: PMC4653743 DOI: 10.1038/srep16506] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 10/15/2015] [Indexed: 11/09/2022] Open
Abstract
Mammalian Spag6 is the orthologue of Chlamydomonas PF16, which encodes a protein localized in the axoneme central apparatus, and regulates flagella/cilia motility. Most Spag6-deficient mice are smaller in size than their littermates. Because SPAG6 decorates microtubules, we hypothesized that SPAG6 has other roles related to microtubule function besides regulating flagellar/cilia motility. Mouse embryonic fibroblasts (MEFs) were isolated from Spag6-deficient and wild-type embryos for these studies. Both primary and immortalized Spag6-deficient MEFs proliferated at a much slower rate than the wild-type MEFs, and they had a larger surface area. Re-expression of SPAG6 in the Spag6-deficient MEFs rescued the abnormal cell morphology. Spag6-deficient MEFs were less motile than wild-type MEFs, as shown by both chemotactic analysis and wound-healing assays. Spag6-deficient MEFs also showed reduced adhesion associated with a non-polarized F-actin distribution. Multiple centrosomes were observed in the Spag6-deficient MEF cultures. The percentage of cells with primary cilia was significantly reduced compared to the wild-type MEFs, and some Spag6-deficient MEFs developed multiple cilia. Furthermore, SPAG6 selectively increased expression of acetylated tubulin, a microtubule stability marker. The Spag6-deficient MEFs were more sensitive to paclitaxel, a microtubule stabilizer. Our studies reveal new roles for SPAG6 in modulation of cell morphology, proliferation, migration, and ciliogenesis.
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Affiliation(s)
- Wei Li
- Department of Obstetrics &Gynecology, Virginia Commonwealth University, Richmond, VA, 23298
| | - Abir Mukherjee
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, VA, 23298
| | - Jinhua Wu
- Department of Obstetrics &Gynecology, Virginia Commonwealth University, Richmond, VA, 23298
| | - Ling Zhang
- Department of Obstetrics &Gynecology, Virginia Commonwealth University, Richmond, VA, 23298.,School of Public Health, Wuhan University of Science and Technology, Wuhan, Hubei 430065, China
| | - Maria E Teves
- Department of Obstetrics &Gynecology, Virginia Commonwealth University, Richmond, VA, 23298
| | - Hongfei Li
- Department of Obstetrics &Gynecology, Virginia Commonwealth University, Richmond, VA, 23298
| | - Shanti Nambiar
- Department of Obstetrics &Gynecology, Virginia Commonwealth University, Richmond, VA, 23298
| | - Scott C Henderson
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA, 23298
| | - Alan R Horwitz
- Department of Cell Biology, University of Virginia, Charlottesville, VA 22908, USA
| | - Jerome F Strauss
- Department of Obstetrics &Gynecology, Virginia Commonwealth University, Richmond, VA, 23298.,Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, VA, 23298
| | - Xianjun Fang
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, VA, 23298
| | - Zhibing Zhang
- Department of Obstetrics &Gynecology, Virginia Commonwealth University, Richmond, VA, 23298.,Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, VA, 23298
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143
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Li L, Yang XJ. Tubulin acetylation: responsible enzymes, biological functions and human diseases. Cell Mol Life Sci 2015; 72:4237-55. [PMID: 26227334 PMCID: PMC11113413 DOI: 10.1007/s00018-015-2000-5] [Citation(s) in RCA: 178] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 07/22/2015] [Accepted: 07/24/2015] [Indexed: 12/28/2022]
Abstract
Microtubules have important functions ranging from maintenance of cell morphology to subcellular transport, cellular signaling, cell migration, and formation of cell polarity. At the organismal level, microtubules are crucial for various biological processes, such as viral entry, inflammation, immunity, learning and memory in mammals. Microtubules are subject to various covalent modifications. One such modification is tubulin acetylation, which is associated with stable microtubules and conserved from protists to humans. In the past three decades, this reversible modification has been studied extensively. In mammals, its level is mainly governed by opposing actions of α-tubulin acetyltransferase 1 (ATAT1) and histone deacetylase 6 (HDAC6). Knockout studies of the mouse enzymes have yielded new insights into biological functions of tubulin acetylation. Abnormal levels of this modification are linked to neurological disorders, cancer, heart diseases and other pathological conditions, thereby yielding important therapeutic implications. This review summarizes related studies and concludes that tubulin acetylation is important for regulating microtubule architecture and maintaining microtubule integrity. Together with detyrosination, glutamylation and other modifications, tubulin acetylation may form a unique 'language' to regulate microtubule structure and function.
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Affiliation(s)
- Lin Li
- Rosalind and Morris Goodman Cancer Research Center, Montreal, QC, H3A 1A3, Canada
- Department of Medicine, Montreal, QC, H3A 1A3, Canada
| | - Xiang-Jiao Yang
- Rosalind and Morris Goodman Cancer Research Center, Montreal, QC, H3A 1A3, Canada.
- Department of Medicine, Montreal, QC, H3A 1A3, Canada.
- Department of Biochemistry, McGill University, Montreal, QC, H3A 1A3, Canada.
- McGill University Health Center, Montreal, QC, H3A 1A3, Canada.
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144
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Biotechnological aspects of cytoskeletal regulation in plants. Biotechnol Adv 2015; 33:1043-62. [DOI: 10.1016/j.biotechadv.2015.03.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2014] [Revised: 03/03/2015] [Accepted: 03/09/2015] [Indexed: 11/23/2022]
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145
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Chauhan S, Ahmed Z, Bradfute SB, Arko-Mensah J, Mandell MA, Won Choi S, Kimura T, Blanchet F, Waller A, Mudd MH, Jiang S, Sklar L, Timmins GS, Maphis N, Bhaskar K, Piguet V, Deretic V. Pharmaceutical screen identifies novel target processes for activation of autophagy with a broad translational potential. Nat Commun 2015; 6:8620. [PMID: 26503418 PMCID: PMC4624223 DOI: 10.1038/ncomms9620] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2015] [Accepted: 09/11/2015] [Indexed: 02/06/2023] Open
Abstract
Autophagy is a conserved homeostatic process active in all human cells and affecting a spectrum of diseases. Here we use a pharmaceutical screen to discover new mechanisms for activation of autophagy. We identify a subset of pharmaceuticals inducing autophagic flux with effects in diverse cellular systems modelling specific stages of several human diseases such as HIV transmission and hyperphosphorylated tau accumulation in Alzheimer's disease. One drug, flubendazole, is a potent inducer of autophagy initiation and flux by affecting acetylated and dynamic microtubules in a reciprocal way. Disruption of dynamic microtubules by flubendazole results in mTOR deactivation and dissociation from lysosomes leading to TFEB (transcription factor EB) nuclear translocation and activation of autophagy. By inducing microtubule acetylation, flubendazole activates JNK1 leading to Bcl-2 phosphorylation, causing release of Beclin1 from Bcl-2-Beclin1 complexes for autophagy induction, thus uncovering a new approach to inducing autophagic flux that may be applicable in disease treatment. Autophagy is a homeostatic process that could be a potential drug target in the treatment of disease. Here the authors identify in a pharmaceutical screen flubendazole as an inducer of autophagy initiation and flux by affecting microtubules, mTOR, TFEB and Beclin 1 activity.
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Affiliation(s)
- Santosh Chauhan
- Department of Molecular Genetics and Microbiology, School of Medicine, University of New Mexico Health Sciences Center, 915 Camino de Salud, NE, Albuquerque, New Mexico 87131, USA
| | - Zahra Ahmed
- Cardiff Institute of Infection &Immunity, Cardiff University, School of Medicine, Henry Wellcome Building, Heath Park CF14 4XN, Cardiff, UK
| | - Steven B Bradfute
- Department of Molecular Genetics and Microbiology, School of Medicine, University of New Mexico Health Sciences Center, 915 Camino de Salud, NE, Albuquerque, New Mexico 87131, USA
| | - John Arko-Mensah
- Department of Molecular Genetics and Microbiology, School of Medicine, University of New Mexico Health Sciences Center, 915 Camino de Salud, NE, Albuquerque, New Mexico 87131, USA
| | - Michael A Mandell
- Department of Molecular Genetics and Microbiology, School of Medicine, University of New Mexico Health Sciences Center, 915 Camino de Salud, NE, Albuquerque, New Mexico 87131, USA
| | - Seong Won Choi
- Department of Molecular Genetics and Microbiology, School of Medicine, University of New Mexico Health Sciences Center, 915 Camino de Salud, NE, Albuquerque, New Mexico 87131, USA
| | - Tomonori Kimura
- Department of Molecular Genetics and Microbiology, School of Medicine, University of New Mexico Health Sciences Center, 915 Camino de Salud, NE, Albuquerque, New Mexico 87131, USA
| | - Fabien Blanchet
- Cardiff Institute of Infection &Immunity, Cardiff University, School of Medicine, Henry Wellcome Building, Heath Park CF14 4XN, Cardiff, UK
| | - Anna Waller
- Department of Pathology, School of Medicine, University of New Mexico Health Sciences Center, 915 Camino de Salud, NE, Albuquerque, New Mexico 87131, USA
| | - Michal H Mudd
- Department of Molecular Genetics and Microbiology, School of Medicine, University of New Mexico Health Sciences Center, 915 Camino de Salud, NE, Albuquerque, New Mexico 87131, USA
| | - Shanya Jiang
- Department of Molecular Genetics and Microbiology, School of Medicine, University of New Mexico Health Sciences Center, 915 Camino de Salud, NE, Albuquerque, New Mexico 87131, USA
| | - Larry Sklar
- Department of Pathology, School of Medicine, University of New Mexico Health Sciences Center, 915 Camino de Salud, NE, Albuquerque, New Mexico 87131, USA
| | - Graham S Timmins
- College of Pharmacy, University of New Mexico Health Sciences Center, 915 Camino de Salud, NE, Albuquerque, New Mexico 87131, USA
| | - Nicole Maphis
- Department of Molecular Genetics and Microbiology, School of Medicine, University of New Mexico Health Sciences Center, 915 Camino de Salud, NE, Albuquerque, New Mexico 87131, USA
| | - Kiran Bhaskar
- Department of Molecular Genetics and Microbiology, School of Medicine, University of New Mexico Health Sciences Center, 915 Camino de Salud, NE, Albuquerque, New Mexico 87131, USA.,Department of Neurology, School of Medicine, University of New Mexico Health Sciences Center, 915 Camino de Salud, NE, Albuquerque, New Mexico 87131, USA
| | - Vincent Piguet
- Cardiff Institute of Infection &Immunity, Cardiff University, School of Medicine, Henry Wellcome Building, Heath Park CF14 4XN, Cardiff, UK
| | - Vojo Deretic
- Department of Molecular Genetics and Microbiology, School of Medicine, University of New Mexico Health Sciences Center, 915 Camino de Salud, NE, Albuquerque, New Mexico 87131, USA.,Department of Neurology, School of Medicine, University of New Mexico Health Sciences Center, 915 Camino de Salud, NE, Albuquerque, New Mexico 87131, USA
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146
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Kim Y, Kang J, Shen B, Wang Y, He Y, Lee M. Open-closed switching of synthetic tubular pores. Nat Commun 2015; 6:8650. [PMID: 26456695 PMCID: PMC4633957 DOI: 10.1038/ncomms9650] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 09/16/2015] [Indexed: 01/28/2023] Open
Abstract
While encouraging progress has been made on switchable nanopores to mimic biological channels and pores, it remains a great challenge to realize long tubular pores with a dynamic open-closed motion. Here we report μm-long, dynamic tubular pores that undergo rapid switching between open and closed states in response to a thermal signal in water. The tubular walls consist of laterally associated primary fibrils stacked from disc-shaped molecules in which the discs readily tilt by means of thermally regulated dehydration of the oligoether chains placed on the wall surfaces. Notably, this pore switching mediates a controlled water-pumping catalytic action for the dehydrative cyclization of adenosine monophosphate to produce metabolically active cyclic adenosine monophosphate. We believe that our work may allow the creation of a variety of dynamic pore structures with complex functions arising from open-closed motion.
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Affiliation(s)
- Yongju Kim
- State Key Laboratory for Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, China
| | - Jiheong Kang
- Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Bowen Shen
- State Key Laboratory for Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, China
| | - Yanqiu Wang
- State Key Laboratory for Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, China
| | - Ying He
- State Key Laboratory for Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, China
| | - Myongsoo Lee
- State Key Laboratory for Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, China
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147
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Barlow PW. The natural history of consciousness, and the question of whether plants are conscious, in relation to the Hameroff-Penrose quantum-physical 'Orch OR' theory of universal consciousness. Commun Integr Biol 2015; 8:e1041696. [PMID: 26478778 PMCID: PMC4594572 DOI: 10.1080/19420889.2015.1041696] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 03/28/2015] [Accepted: 04/13/2015] [Indexed: 12/23/2022] Open
Affiliation(s)
- Peter W Barlow
- School of Biological Sciences; University of Bristol; Bristol Life Sciences Building; Bristol, UK
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148
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Structural basis of cofactor-mediated stabilization and substrate recognition of the α-tubulin acetyltransferase αTAT1. Biochem J 2015; 467:103-13. [PMID: 25602620 DOI: 10.1042/bj20141193] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The functions of microtubules are controlled in part by tubulin post-translational modification including acetylation of Lys⁴⁰ in α-tubulin. αTAT1 (α-tubulin acetyltransferase 1), an enzyme evolutionarily conserved among eukaryotes, has recently been identified as the major α-tubulin Lys⁴⁰ acetyltransferase, in which AcCoA (acetyl-CoA) serves as an acetyl group donor. The regulation and substrate recognition of this enzyme, however, have not been fully understood. In the present study, we show that AcCoA and CoA each form a stable complex with human αTAT1 to maintain the protein integrity both in vivo and in vitro. The invariant residues Arg¹³² and Ser¹⁶⁰ in αTAT1 participate in the stable interaction not only with AcCoA but also with CoA, which is supported by analysis of the present crystal structures of the αTAT1 catalytic domain in complex with CoA. Alanine substitution for Arg¹³² or Ser¹⁶⁰ leads to a drastic misfolding of the isolated αTAT1 catalytic domain in the absence of CoA and AcCoA but not in the presence of excess amounts of either cofactor. A mutant αTAT1 carrying the R132A or S160A substitution is degraded much faster than the wild-type protein when expressed in mammalian Madin-Darby canine kidney cells. Furthermore, alanine-scanning experiments using Lys⁴⁰-containing peptides reveal that α-tubulin Ser³⁸ is crucial for substrate recognition of αTAT1, whereas Asp³⁹, Ile⁴², the glycine stretch (amino acid residues 43-45) and Asp⁴⁶ are also involved. The requirement for substrate selection is totally different from that in various histone acetyltransferases, which appears to be consistent with the inability of αTAT1 to acetylate histones.
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149
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Abstract
Microtubules give rise to intracellular structures with diverse morphologies and dynamics that are crucial for cell division, motility, and differentiation. They are decorated with abundant and chemically diverse posttranslational modifications that modulate their stability and interactions with cellular regulators. These modifications are important for the biogenesis and maintenance of complex microtubule arrays such as those found in spindles, cilia, neuronal processes, and platelets. Here we discuss the nature and subcellular distribution of these posttranslational marks whose patterns have been proposed to constitute a tubulin code that is interpreted by cellular effectors. We review the enzymes responsible for writing the tubulin code, explore their functional consequences, and identify outstanding challenges in deciphering the tubulin code.
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Affiliation(s)
- Ian Yu
- From the Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, NINDS, and
| | - Christopher P Garnham
- From the Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, NINDS, and
| | - Antonina Roll-Mecak
- From the Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, NINDS, and NHLBI, National Institutes of Health, Bethesda, Maryland 20892
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150
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Garnham CP, Vemu A, Wilson-Kubalek EM, Yu I, Szyk A, Lander GC, Milligan RA, Roll-Mecak A. Multivalent Microtubule Recognition by Tubulin Tyrosine Ligase-like Family Glutamylases. Cell 2015; 161:1112-1123. [PMID: 25959773 DOI: 10.1016/j.cell.2015.04.003] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2014] [Revised: 01/29/2015] [Accepted: 03/11/2015] [Indexed: 12/30/2022]
Abstract
Glutamylation, the most prevalent tubulin posttranslational modification, marks stable microtubules and regulates recruitment and activity of microtubule- interacting proteins. Nine enzymes of the tubulin tyrosine ligase-like (TTLL) family catalyze glutamylation. TTLL7, the most abundant neuronal glutamylase, adds glutamates preferentially to the β-tubulin tail. Coupled with ensemble and single-molecule biochemistry, our hybrid X-ray and cryo-electron microscopy structure of TTLL7 bound to the microtubule delineates a tripartite microtubule recognition strategy. The enzyme uses its core to engage the disordered anionic tails of α- and β-tubulin, and a flexible cationic domain to bind the microtubule and position itself for β-tail modification. Furthermore, we demonstrate that all single-chain TTLLs with known glutamylase activity utilize a cationic microtubule-binding domain analogous to that of TTLL7. Therefore, our work reveals the combined use of folded and intrinsically disordered substrate recognition elements as the molecular basis for specificity among the enzymes primarily responsible for chemically diversifying cellular microtubules.
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Affiliation(s)
- Christopher P Garnham
- Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA
| | - Annapurna Vemu
- Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA
| | | | - Ian Yu
- Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA
| | - Agnieszka Szyk
- Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA
| | | | | | - Antonina Roll-Mecak
- Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA; National Heart, Lung and Blood Institute, Bethesda, MD 20892, USA.
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