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Oddoux S, Randazzo D, Kenea A, Alonso B, Zaal KJM, Ralston E. Misplaced Golgi Elements Produce Randomly Oriented Microtubules and Aberrant Cortical Arrays of Microtubules in Dystrophic Skeletal Muscle Fibers. Front Cell Dev Biol 2019; 7:176. [PMID: 31620435 PMCID: PMC6759837 DOI: 10.3389/fcell.2019.00176] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 08/13/2019] [Indexed: 12/14/2022] Open
Abstract
Differentiated mammalian cells and tissues, such as skeletal muscle fibers, acquire an organization of Golgi complex and microtubules profoundly different from that in proliferating cells and still poorly understood. In adult rodent skeletal muscle, the multinucleated muscle fibers have hundreds of Golgi elements (GE), small stacks of cisternae that serve as microtubule-organizing centers. We are interested in the role of the GE in organizing a peculiar grid of microtubules located in the fiber cortex, against the sarcolemma. Modifications of this grid in the mdx mouse model of Duchenne muscular dystrophy have led to identifying dystrophin, the protein missing in both human disease and mouse model, as a microtubule guide. Compared to wild-type (WT), mdx microtubules are disordered and more dense and they have been linked to the dystrophic pathology. GE themselves are disordered in mdx. Here, to identify the causes of GE and microtubule alterations in the mdx muscle, we follow GFP-tagged microtubule markers in live mdx fibers and investigate the recovery of GE and microtubules after treatment with nocodazole. We find that mdx microtubules grow 10% faster but in 30% shorter bouts and that they begin to form a tangled network, rather than an orthogonal grid, right after nucleation from GE. Strikingly, a large fraction of microtubules in mdx muscle fibers seem to dissociate from GE after nucleation. Moreover, we report that mdx GE are mispositioned and increased in number and size. These results were replicated in WT fibers overexpressing the beta-tubulin tubb6, which is elevated in Duchenne muscular dystrophy, in mdx and in regenerating muscle. Finally, we examine the association of GE with ER exit sites and ER-to-Golgi intermediate compartment, which starts during muscle differentiation, and find it persisting in mdx and tubb6 overexpressing fibers. We conclude that GE are full, small, Golgi complexes anchored, and positioned through ER Exit Sites. We propose a model in which GE mispositioning, together with the absence of microtubule guidance due to the lack of dystrophin, determines the differences in GE and microtubule organization between WT and mdx muscle fibers.
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Affiliation(s)
- Sarah Oddoux
- Light Imaging Section, Office of Science and Technology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Davide Randazzo
- Light Imaging Section, Office of Science and Technology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Aster Kenea
- Light Imaging Section, Office of Science and Technology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Bruno Alonso
- Light Imaging Section, Office of Science and Technology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Kristien J M Zaal
- Light Imaging Section, Office of Science and Technology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Evelyn Ralston
- Light Imaging Section, Office of Science and Technology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, United States
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2
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Rodríguez-Cruz F, Torres-Cruz FM, Monroy-Ramírez HC, Escobar-Herrera J, Basurto-Islas G, Avila J, García-Sierra F. Fragmentation of the Golgi Apparatus in Neuroblastoma Cells Is Associated with Tau-Induced Ring-Shaped Microtubule Bundles. J Alzheimers Dis 2019; 65:1185-1207. [PMID: 30124450 DOI: 10.3233/jad-180547] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Abnormal fibrillary aggregation of tau protein is a pathological condition observed in Alzheimer's disease and other tauopathies; however, the presence and pathological significance of early non-fibrillary aggregates of tau remain under investigation. In cell and animal models expressing normal or modified tau, toxic effects altering the structure and function of several membranous organelles have also been reported in the absence of fibrillary structures; however, how these abnormalities are produced is an issue yet to be addressed. In order to obtain more insights into the mechanisms by which tau may disturb intracellular membranous elements, we transiently overexpressed human full-length tau and several truncated tau variants in cultured neuroblastoma cells. After 48 h of transfection, either full-length or truncated tau forms produced significant fragmentation of the Golgi apparatus (GA) with no changes in cell viability. Noteworthy is that in the majority of cells exhibiting dispersion of the GA, a ring-shaped array of cortical or perinuclear microtubule (Mt) bundles was also generated under the expression of either variant of tau. In contrast, Taxol treatment of non-transfected cells increased the amount of Mt bundles but not sufficiently to produce fragmentation of the GA. Tau-induced ring-shaped Mt bundles appeared to be well-organized and stable structures because they were resistant to Nocodazole post-treatment and displayed a high level of tubulin acetylation. These results further indicate that a mechanical force generated by tau-induced Mt-bundling may be responsible for Golgi fragmentation and that the repeated domain region of tau may be the main promoter of this effect.
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Affiliation(s)
- Fanny Rodríguez-Cruz
- Department of Cell Biology, Center of Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV), Mexico City, Mexico
| | - Francisco Miguel Torres-Cruz
- Department of Cell Biology, Center of Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV), Mexico City, Mexico
| | | | - Jaime Escobar-Herrera
- Department of Cell Biology, Center of Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV), Mexico City, Mexico
| | | | - Jesús Avila
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM) Universidad Autónoma de Madrid, Madrid, Spain
| | - Francisco García-Sierra
- Department of Cell Biology, Center of Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV), Mexico City, Mexico
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3
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She ZY, Pan MY, Tan FQ, Yang WX. Minus end-directed kinesin-14 KIFC1 regulates the positioning and architecture of the Golgi apparatus. Oncotarget 2018; 8:36469-36483. [PMID: 28430595 PMCID: PMC5482669 DOI: 10.18632/oncotarget.16863] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 03/27/2017] [Indexed: 11/25/2022] Open
Abstract
The Golgi apparatus is the central organelle along the eukaryotic secretory and endocytic pathway. In non-polarized mammalian cells, the Golgi complex is usually located proximal to the nucleus at the cell center and is closely associated with the microtubule organizing center. Microtubule networks are essential in the organization and central localization of the Golgi apparatus, but the molecular basis underlying these processes are poorly understood. Here we reveal that minus end-directed kinesin-14 KIFC1 proteins are required for the structural integrity and positioning of the Golgi complex in non-polarized mammalian cells. Remarkably, we found that the motor domain of kinesin-14 KIFC1 regulates the recognition and binding of the Golgi and KIFC1 also statically binds to the microtubules via its tail domain. These findings reveal a new stationary binding model that kinesin-14 KIFC1 proteins function as crosslinkers between the Golgi apparatus and the microtubules and contribute to the central positioning and structural maintenance of the Golgi apparatus.
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Affiliation(s)
- Zhen-Yu She
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Meng-Ying Pan
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Fu-Qing Tan
- The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, China
| | - Wan-Xi Yang
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
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4
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Bjørklund G, Dadar M, Mutter J, Aaseth J. The toxicology of mercury: Current research and emerging trends. ENVIRONMENTAL RESEARCH 2017; 159:545-554. [PMID: 28889024 DOI: 10.1016/j.envres.2017.08.051] [Citation(s) in RCA: 240] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 08/27/2017] [Accepted: 08/30/2017] [Indexed: 05/16/2023]
Abstract
Mercury (Hg) is a persistent bio-accumulative toxic metal with unique physicochemical properties of public health concern since their natural and anthropogenic diffusions still induce high risk to human and environmental health. The goal of this review was to analyze scientific literature evaluating the role of global concerns over Hg exposure due to human exposure to ingestion of contaminated seafood (methyl-Hg) as well as elemental Hg levels of dental amalgam fillings (metallic Hg), vaccines (ethyl-Hg) and contaminated water and air (Hg chloride). Mercury has been recognized as a neurotoxicant as well as immunotoxic and designated by the World Health Organization as one of the ten most dangerous chemicals to public health. It has been shown that the half-life of inorganic Hg in human brains is several years to several decades. Mercury occurs in the environment under different chemical forms as elemental Hg (metallic), inorganic and organic Hg. Despite the raising understanding of the Hg toxicokinetics, there is still fully justified to further explore the emerging theories about its bioavailability and adverse effects in humans. In this review, we describe current research and emerging trends in Hg toxicity with the purpose of providing up-to-date information for a better understanding of the kinetics of this metal, presenting comprehensive knowledge on published data analyzing its metabolism, interaction with other metals, distribution, internal doses and targets, and reservoir organs.
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Affiliation(s)
- Geir Bjørklund
- Council for Nutritional and Environmental Medicine, Toften 24, 8610 Mo i Rana, Norway.
| | - Maryam Dadar
- Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran
| | | | - Jan Aaseth
- Innlandet Hospital Trust and Inland Norway University of Applied Sciences, Elverum, Norway
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5
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van de Meene AML, Doblin MS, Bacic A. The plant secretory pathway seen through the lens of the cell wall. PROTOPLASMA 2017; 254:75-94. [PMID: 26993347 DOI: 10.1007/s00709-016-0952-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 01/27/2016] [Accepted: 02/01/2016] [Indexed: 05/18/2023]
Abstract
Secretion in plant cells is often studied by looking at well-characterised, evolutionarily conserved membrane proteins associated with particular endomembrane compartments. Studies using live cell microscopy and fluorescent proteins have illuminated the highly dynamic nature of trafficking, and electron microscopy studies have resolved the ultrastructure of many compartments. Biochemical and molecular analyses have further informed about the function of particular proteins and endomembrane compartments. In plants, there are over 40 cell types, each with highly specialised functions, and hence potential variations in cell biological processes and cell wall structure. As the primary function of secretion in plant cells is for the biosynthesis of cell wall polysaccharides and apoplastic transport complexes, it follows that utilising our knowledge of cell wall glycosyltransferases (GTs) and their polysaccharide products will inform us about secretion. Indeed, this knowledge has led to novel insights into the secretory pathway, including previously unseen post-TGN secretory compartments. Conversely, our knowledge of trafficking routes of secretion will inform us about polarised and localised deposition of cell walls and their constituent polysaccharides/glycoproteins. In this review, we look at what is known about cell wall biosynthesis and the secretory pathway and how the different approaches can be used in a complementary manner to study secretion and provide novel insights into these processes.
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Affiliation(s)
- A M L van de Meene
- ARC Centre of Excellence in Plant Cell Walls, School of BioSciences, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - M S Doblin
- ARC Centre of Excellence in Plant Cell Walls, School of BioSciences, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Antony Bacic
- ARC Centre of Excellence in Plant Cell Walls, School of BioSciences, The University of Melbourne, Parkville, Victoria, 3010, Australia.
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6
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CAMSAP3-dependent microtubule dynamics regulates Golgi assembly in epithelial cells. J Genet Genomics 2017; 44:39-49. [DOI: 10.1016/j.jgg.2016.11.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 11/19/2016] [Accepted: 11/30/2016] [Indexed: 11/24/2022]
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7
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Tisdale EJ, Talati NK, Artalejo CR, Shisheva A. GAPDH binds Akt to facilitate cargo transport in the early secretory pathway. Exp Cell Res 2016; 349:310-319. [PMID: 27818247 DOI: 10.1016/j.yexcr.2016.10.025] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 10/12/2016] [Accepted: 10/31/2016] [Indexed: 01/12/2023]
Abstract
Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) undergoes numerous post-translational modifications, which impart new function and influence intracellular location. For example, atypical PKC ι/λ phosphorylates GAPDH that locates to vesicular tubular clusters and is required for retrograde membrane trafficking in the early secretory pathway. GAPDH is also required in the endocytic pathway; substitution of Pro234 to Ser (Pro234Ser) rendered CHO cells defective in endocytosis. To determine if GAPDH (Pro234Ser) could inhibit endoplasmic reticulum to Golgi trafficking, we introduced the recombinant mutant enzyme into several biochemical and morphological transport assays. The mutant protein efficiently blocked vesicular stomatitis virus-G protein transport. Because GAPDH binds to microtubules (MTs), we evaluated MT binding and MT intracellular distribution in the presence of the mutant. Although these properties were not changed relative to wild-type, GAPDH (Pro234Ser) altered Golgi complex morphology. We determined that the GAPDH point mutation disrupted association between the enzyme and the serine/threonine kinase Akt. Interestingly Rab1, which functions in anterograde-directed trafficking, stimulates GAPDH-Akt association with membranes in a quantitative binding assay. In contrast, Rab2 does not stimulate GAPDH-Akt membrane binding but instead recruits GAPDH-aPKC. We propose a mechanism whereby the association of GAPDH with Akt or with aPKC serves as a switch to discriminate between anterograde directed cargo and recycling cargo retrieved back to the ER, respectively.
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Affiliation(s)
- Ellen J Tisdale
- Department of Pharmacology, Wayne State University School of Medicine, 540 E. Canfield Ave., 6374 Scott Hall, Detroit, MI 48201, USA.
| | - Nikunj K Talati
- Department of Pharmacology, Wayne State University School of Medicine, 540 E. Canfield Ave., 6374 Scott Hall, Detroit, MI 48201, USA
| | - Cristina R Artalejo
- Department of Pharmacology, Wayne State University School of Medicine, 540 E. Canfield Ave., 6374 Scott Hall, Detroit, MI 48201, USA
| | - Assia Shisheva
- Department of Physiology, Wayne State University School of Medicine, 540 E. Canfield Ave., 6374 Scott Hall, Detroit, MI 48201, USA
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8
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Antón-Fernández A, Aparicio-Torres G, Tapia S, DeFelipe J, Muñoz A. Morphometric alterations of Golgi apparatus in Alzheimer's disease are related to tau hyperphosphorylation. Neurobiol Dis 2016; 97:11-23. [PMID: 27793637 PMCID: PMC5176038 DOI: 10.1016/j.nbd.2016.10.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 10/03/2016] [Accepted: 10/23/2016] [Indexed: 12/19/2022] Open
Abstract
The Golgi apparatus (GA) is a highly dynamic organelle, which is mainly involved in the post-translational processing and targeting of cellular proteins and which undergoes significant morphological changes in response to different physiological and pathological conditions. In the present study, we have analyzed the possible alterations of GA in neurons from the temporal neocortex and hippocampus of Alzheimer's disease (AD) patients, using double immunofluorescence techniques, confocal microscopy and 3D quantification techniques. We found that in AD patients, the percentage of temporal neocortical and CA1 hippocampal pyramidal neurons with a highly altered GA is much higher (approximately 65%) in neurons with neurofibrillary tangles (NFT) than in NFT-free neurons (approximately 6%). Quantitative analysis of the surface area and volume of GA elements in neurons revealed that, compared with NFT-free neurons, NFT-bearing neurons had a reduction of approximately one half in neocortical neurons and one third in CA1 neurons. In both regions, neurons with a pre-tangle stage of phospho-tau accumulation had surface area and GA volume values that were intermediate, that is, between those of NFT-free and NFT-bearing neurons. These findings support the idea that the progressive accumulation of phospho-tau is associated with structural alterations of the GA including fragmentation and a decrease in the surface area and volume of GA elements. These alterations likely impact the processing and trafficking of proteins, which might contribute to neuronal dysfunction in AD.
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Affiliation(s)
- Alejandro Antón-Fernández
- Instituto Cajal, CSIC, Madrid, Spain; Laboratorio Cajal de Circuitos Corticales (CTB), Universidad Politécnica de Madrid, Madrid, Spain
| | - Guillermo Aparicio-Torres
- Instituto Cajal, CSIC, Madrid, Spain; Laboratorio Cajal de Circuitos Corticales (CTB), Universidad Politécnica de Madrid, Madrid, Spain
| | - Silvia Tapia
- Instituto Cajal, CSIC, Madrid, Spain; Laboratorio Cajal de Circuitos Corticales (CTB), Universidad Politécnica de Madrid, Madrid, Spain
| | - Javier DeFelipe
- Instituto Cajal, CSIC, Madrid, Spain; Laboratorio Cajal de Circuitos Corticales (CTB), Universidad Politécnica de Madrid, Madrid, Spain; CIBERNED, Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas, Spain
| | - Alberto Muñoz
- Instituto Cajal, CSIC, Madrid, Spain; Laboratorio Cajal de Circuitos Corticales (CTB), Universidad Politécnica de Madrid, Madrid, Spain; Department of Cell Biology, Complutense University, Madrid, Spain.
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9
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Dynein Dysfunction Reproduces Age-Dependent Retromer Deficiency: Concomitant Disruption of Retrograde Trafficking Is Required for Alteration in β-Amyloid Precursor Protein Metabolism. THE AMERICAN JOURNAL OF PATHOLOGY 2016; 186:1952-1966. [PMID: 27179390 DOI: 10.1016/j.ajpath.2016.03.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 03/01/2016] [Accepted: 03/07/2016] [Indexed: 11/21/2022]
Abstract
It is widely accepted that β-amyloid (Aβ) protein plays a pivotal role in Alzheimer disease pathogenesis, and accumulating evidence suggests that endocytic dysfunction is involved in Aβ pathology. Retromer, a conserved multisubunit complex, mediates the retrograde transport of numerous kinds of cargo from endosomes to the trans-Golgi network. Several studies have found that retromer deficiency enhances Aβ pathology both in vitro and in vivo. Cytoplasmic dynein, a microtubule-based motor protein, mediates minus-end-directed vesicle transport via interactions with dynactin, another microtubule-associated protein that also interacts with retromer. Aging attenuates the dynein-dynactin interaction, and dynein dysfunction reproduces age-dependent endocytic disturbance, resulting in the intracellular accumulation of beta-amyloid precursor protein (APP) and its β-cleavage products, including Aβ. Here, we report that aging itself affects retromer trafficking in cynomolgus monkey brains. In addition, dynein dysfunction reproduces this type of age-dependent retromer deficiency (ie, the endosomal accumulation of retromer-related proteins and APP. Moreover, we found that knockdown of Rab7, Rab9, or Rab11 did not alter endogenous APP metabolism, such as that observed in aged monkey brains and in dynein-depleted cells. These findings suggest that dynein dysfunction can cause retromer deficiency and that concomitant disruption of retrograde trafficking may be the key factor underlying age-dependent Aβ pathology.
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10
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Copeland SJ, Thurston SF, Copeland JW. Actin- and microtubule-dependent regulation of Golgi morphology by FHDC1. Mol Biol Cell 2015; 27:260-76. [PMID: 26564798 PMCID: PMC4713130 DOI: 10.1091/mbc.e15-02-0070] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 11/04/2015] [Indexed: 01/08/2023] Open
Abstract
The coordinated action of the actin and microtubule cytoskeletal networks is required for Golgi ribbon assembly. The novel formin FHDC1 accumulates on the Golgi-derived microtubule network, where it acts to regulate Golgi ribbon assembly in an actin- and microtubule-dependent manner. The Golgi apparatus is the central hub of intracellular trafficking and consists of tethered stacks of cis, medial, and trans cisternae. In mammalian cells, these cisternae are stitched together as a perinuclear Golgi ribbon, which is required for the establishment of cell polarity and normal subcellular organization. We previously identified FHDC1 (also known as INF1) as a unique microtubule-binding member of the formin family of cytoskeletal-remodeling proteins. We show here that endogenous FHDC1 regulates Golgi ribbon formation and has an apparent preferential association with the Golgi-derived microtubule network. Knockdown of FHDC1 expression results in defective Golgi assembly and suggests a role for FHDC1 in maintenance of the Golgi-derived microtubule network. Similarly, overexpression of FHDC1 induces dispersion of the Golgi ribbon into functional ministacks. This effect is independent of centrosome-derived microtubules and instead likely requires the interaction between the FHDC1 microtubule-binding domain and the Golgi-derived microtubule network. These effects also depend on the interaction between the FHDC1 FH2 domain and the actin cytoskeleton. Thus our results suggest that the coordination of actin and microtubule dynamics by FHDC1 is required for normal Golgi ribbon formation.
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Affiliation(s)
- Sarah J Copeland
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Susan F Thurston
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - John W Copeland
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
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11
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Vasiliev JM, Samoylov VI. Regulatory functions of microtubules. BIOCHEMISTRY (MOSCOW) 2014; 78:37-40. [PMID: 23379557 DOI: 10.1134/s0006297913010045] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
This mini-review summarizes literature and original data about the role of microtubules in interphase animal cells. Recent data have shown that functioning of microtubules is essential for such diverse phenomena as directional cell movements, distribution of organelles in the cytoplasm, and neuronal memory in the central nervous system. It is suggested that microtubules can act as an important regulatory system in eukaryotic cells. Possible mechanisms of these functions are discussed.
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Affiliation(s)
- J M Vasiliev
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.
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12
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Deakin NO, Turner CE. Paxillin inhibits HDAC6 to regulate microtubule acetylation, Golgi structure, and polarized migration. ACTA ACUST UNITED AC 2014; 206:395-413. [PMID: 25070956 PMCID: PMC4121979 DOI: 10.1083/jcb.201403039] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Polarized cell migration is essential for normal organism development and is also a critical component of cancer cell invasion and disease progression. Directional cell motility requires the coordination of dynamic cell-extracellular matrix interactions as well as repositioning of the Golgi apparatus, both of which can be controlled by the microtubule (MT) cytoskeleton. In this paper, we have identified a new and conserved role for the focal adhesion scaffold protein paxillin in regulating the posttranslational modification of the MT cytoskeleton through an inhibitory interaction with the α-tubulin deacetylase HDAC6. We also determined that through HDAC6-dependent regulation of the MT cytoskeleton, paxillin regulates both Golgi organelle integrity and polarized cell invasion and migration in both three-dimensional and two-dimensional matrix microenvironments. Importantly, these data reveal a fundamental role for paxillin in coordinating MT acetylation-dependent cell polarization and migration in both normal and transformed cells.
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Affiliation(s)
- Nicholas O Deakin
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, NY 13210
| | - Christopher E Turner
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, NY 13210
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13
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Berto GE, Iobbi C, Camera P, Scarpa E, Iampietro C, Bianchi F, Gai M, Sgrò F, Cristofani F, Gärtner A, Dotti CG, Di Cunto F. The DCR protein TTC3 affects differentiation and Golgi compactness in neurons through specific actin-regulating pathways. PLoS One 2014; 9:e93721. [PMID: 24695496 PMCID: PMC3973554 DOI: 10.1371/journal.pone.0093721] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Accepted: 03/06/2014] [Indexed: 01/10/2023] Open
Abstract
In neuronal cells, actin remodeling plays a well known role in neurite extension but is also deeply involved in the organization of intracellular structures, such as the Golgi apparatus. However, it is still not very clear which mechanisms may regulate actin dynamics at the different sites. In this report we show that high levels of the TTC3 protein, encoded by one of the genes of the Down Syndrome Critical Region (DCR), prevent neurite extension and disrupt Golgi compactness in differentiating primary neurons. These effects largely depend on the capability of TTC3 to promote actin polymerization through signaling pathways involving RhoA, ROCK, CIT-N and PIIa. However, the functional relationships between these molecules differ significantly if considering the TTC3 activity on neurite extension or on Golgi organization. Finally, our results reveal an unexpected stage-dependent requirement for F-actin in Golgi organization at different stages of neuronal differentiation.
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Affiliation(s)
- Gaia Elena Berto
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
- * E-mail: (GEB); (FDC)
| | - Cristina Iobbi
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Paola Camera
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Elena Scarpa
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Corinne Iampietro
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Federico Bianchi
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Marta Gai
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Francesco Sgrò
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Flavio Cristofani
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Annette Gärtner
- VIB Center for the Biology of Disease – VIB, Leuven, Belgium
| | - Carlos G. Dotti
- VIB Center for the Biology of Disease – VIB, Leuven, Belgium
- Centro de Biología Molecular Severo Ochoa, CSIC/UAM, Madrid, Spain
| | - Ferdinando Di Cunto
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
- * E-mail: (GEB); (FDC)
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14
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Dong Z, Zuber C, Pierce M, Stanley P, Roth J. Reduction in Golgi apparatus dimension in the absence of a residential protein, N-acetylglucosaminyltransferase V. Histochem Cell Biol 2014; 141:153-64. [PMID: 24078077 PMCID: PMC4085668 DOI: 10.1007/s00418-013-1146-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/04/2013] [Indexed: 11/28/2022]
Abstract
Various proteins are involved in the generation and maintenance of the membrane complex known as the Golgi apparatus. We have used mutant Chinese hamster ovary (CHO) cell lines Lec4 and Lec4A lacking N-acetylglucosaminyltransferase V (GlcNAcT-V, MGAT5) activity and protein in the Golgi apparatus to study the effects of the absence of a single glycosyltransferase on the Golgi apparatus dimension. Quantification of immunofluorescence in serial confocal sections for Golgi α-mannosidase II and electron microscopic morphometry revealed a reduction in Golgi volume density up to 49 % in CHO Lec4 and CHO Lec4A cells compared to parental CHO cells. This reduction in Golgi volume density could be reversed by stable transfection of Lec4 cells with a cDNA encoding Mgat5. Inhibition of the synthesis of β1,6-branched N-glycans by swainsonine had no effect on Golgi volume density. In addition, no effect on Golgi volume density was observed in CHO Lec1 cells that contain enzymatically active GlcNAcT-V, but cannot synthesize β1,6-branched glycans due to an inactive GlcNAcT-I in their Golgi apparatus. These results indicate that it may be the absence of the GlcNAcT-V protein that is the determining factor in reducing Golgi volume density. No dimensional differences existed in cross-sectioned cisternal stacks between Lec4 and control CHO cells, but significantly reduced Golgi stack hits were observed in cross-sectioned Lec4 cells. Therefore, the Golgi apparatus dimensional change in Lec4 and Lec4A cells may be due to a compaction of the organelle.
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Affiliation(s)
- Zhizhong Dong
- Division of Cell and Molecular Pathology, Department of Pathology, University of Zürich, 8091 Zürich, Switzerland
| | - Christian Zuber
- Division of Cell and Molecular Pathology, Department of Pathology, University of Zürich, 8091 Zürich, Switzerland
| | - Michael Pierce
- Complex Carbohydrate Research Center, Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Pamela Stanley
- Department of Cell Biology, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Jürgen Roth
- Division of Cell and Molecular Pathology, Department of Pathology, University of Zürich, 8091 Zürich, Switzerland
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15
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Teamwork in microtubule motors. Trends Cell Biol 2013; 23:575-82. [PMID: 23877011 DOI: 10.1016/j.tcb.2013.06.003] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 06/11/2013] [Accepted: 06/17/2013] [Indexed: 01/10/2023]
Abstract
Diverse cellular processes are driven by the collective force from multiple motor proteins. Disease-causing mutations cause aberrant function of motors, but the impact is observed at a cellular level and beyond, therefore necessitating an understanding of cell mechanics at the level of motor molecules. One way to do this is by measuring the force generated by ensembles of motors in vivo at single-motor resolution. This has been possible for microtubule motor teams that transport intracellular organelles, revealing unexpected differences between collective and single-molecule function. Here we review how the biophysical properties of single motors, and differences therein, may translate into collective motor function during organelle transport and perhaps in other processes outside transport.
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16
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Abstract
The Golgi complex is considered the central station of the secretory pathway where cargo proteins and lipids are properly modified, classified, packed into specific carriers and delivered to their final destinations. Early electron microscope studies showed the extraordinary structural complexity of this organelle. However, despite the large volume of incoming and outgoing traffic, it is able to maintain its architecture, although it is also flexible enough to adapt to the functional status of the cell. Many components of the molecular machinery involved in membrane traffic and other Golgi functions have been identified. However, some basic aspects of Golgi functioning remain unsolved. For instance, how cargo moves through the stack remains controversial and two classical models have been proposed: vesicular transport and cisternal maturation. Since neither of these models explains all the experimental data, a combination of these models as well as new models have been proposed. In this context, the specific role of the cisternae, vesicles and tubules needs to be clarified. In this review, we summarize our current knowledge of the Golgi organization and function, focusing on the mechanisms of intra-Golgi transport.
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17
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Ryan SD, Bhanot K, Ferrier A, De Repentigny Y, Chu A, Blais A, Kothary R. Microtubule stability, Golgi organization, and transport flux require dystonin-a2-MAP1B interaction. ACTA ACUST UNITED AC 2012; 196:727-42. [PMID: 22412020 PMCID: PMC3308695 DOI: 10.1083/jcb.201107096] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Loss of interaction between the dystonin-a2 isoform and the microtubule-associated protein MAP1B induces microtubule instability and trafficking defects that may underlie certain neuropathies. Loss of function of dystonin cytoskeletal linker proteins causes neurodegeneration in dystonia musculorum (dt) mutant mice. Although much investigation has focused on understanding dt pathology, the diverse cellular functions of dystonin isoforms remain poorly characterized. In this paper, we highlight novel functions of the dystonin-a2 isoform in mediating microtubule (MT) stability, Golgi organization, and flux through the secretory pathway. Using dystonin mutant mice combined with isoform-specific loss-of-function analysis, we found dystonin-a2 bound to MT-associated protein 1B (MAP1B) in the centrosomal region, where it maintained MT acetylation. In dt neurons, absence of the MAP1B–dystonin-a2 interaction resulted in altered MAP1B perikaryal localization, leading to MT deacetylation and instability. Deacetylated MT accumulation resulted in Golgi fragmentation and prevented anterograde trafficking via motor proteins. Maintenance of MT acetylation through trichostatin A administration or MAP1B overexpression mitigated the observed defect. These cellular aberrations are apparent in prephenotype dorsal root ganglia and primary sensory neurons from dt mice, suggesting they are causal in the disorder.
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Affiliation(s)
- Scott D Ryan
- Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada
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18
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Vinogradova T, Paul R, Grimaldi AD, Loncarek J, Miller PM, Yampolsky D, Magidson V, Khodjakov A, Mogilner A, Kaverina I. Concerted effort of centrosomal and Golgi-derived microtubules is required for proper Golgi complex assembly but not for maintenance. Mol Biol Cell 2012; 23:820-33. [PMID: 22262454 PMCID: PMC3290642 DOI: 10.1091/mbc.e11-06-0550] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Using computational modeling and laser microsurgery, we establish that neither the centrosomal microtubule array nor the Golgi-derived array is solely sufficient for correct Golgi assembly. Only the concerted effort of both MT arrays results in the integral, polarized Golgi complex necessary for polarized trafficking and cell motility. Assembly of an integral Golgi complex is driven by microtubule (MT)-dependent transport. Conversely, the Golgi itself functions as an unconventional MT-organizing center (MTOC). This raises the question of whether Golgi assembly requires centrosomal MTs or can be self-organized, relying on its own MTOC activity. The computational model presented here predicts that each MT population is capable of gathering Golgi stacks but not of establishing Golgi complex integrity or polarity. In contrast, the concerted effort of two MT populations would assemble an integral, polarized Golgi complex. Indeed, while laser ablation of the centrosome did not alter already-formed Golgi complexes, acentrosomal cells fail to reassemble an integral complex upon nocodazole washout. Moreover, polarity of post-Golgi trafficking was compromised under these conditions, leading to strong deficiency in polarized cell migration. Our data indicate that centrosomal MTs complement Golgi self-organization for proper Golgi assembly and motile-cell polarization.
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Affiliation(s)
- Tatiana Vinogradova
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
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Manneville JB, Etienne-Manneville S. Positioning centrosomes and spindle poles: looking at the periphery to find the centre. Biol Cell 2012; 98:557-65. [PMID: 16907664 DOI: 10.1042/bc20060017] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Centrosome positioning is tightly controlled throughout the cell cycle and probably shares common regulatory mechanisms with spindle-pole positioning. In this article, we detail the possible mechanisms controlling centrosome and spindle positioning in various organisms both in interphase and mitotic cells, and discuss recent findings showing how microtubule plus-end-associated proteins interact with the cell cortex. We suggest that microtubule plus-end complexes simultaneously regulate microtubule dynamics and microtubule anchoring at the cell periphery to allow proper centrosome and spindle-pole positioning.
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20
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Zilberman Y, Alieva NO, Miserey-Lenkei S, Lichtenstein A, Kam Z, Sabanay H, Bershadsky A. Involvement of the Rho-mDia1 pathway in the regulation of Golgi complex architecture and dynamics. Mol Biol Cell 2011; 22:2900-11. [PMID: 21680709 PMCID: PMC3154885 DOI: 10.1091/mbc.e11-01-0007] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
A study of the role of actin cytoskeleton regulation in Golgi organization and function shows that Rho regulates Golgi fragmentation into ministacks, as well as formation of Rab6-positive Golgi-derived vesicles, via mDia1 formin activation. The Rho–mDia1 pathway affects the Golgi complex by controlling fusion and fission of Golgi membranes. In mammalian cells, the Golgi apparatus is a ribbon-like, compact structure composed of multiple membrane stacks connected by tubular bridges. Microtubules are known to be important to Golgi integrity, but the role of the actin cytoskeleton in the maintenance of Golgi architecture remains unclear. Here we show that an increase in Rho activity, either by treatment of cells with lysophosphatidic acid or by expression of constitutively active mutants, resulted in pronounced fragmentation of the Golgi complex into ministacks. Golgi dispersion required the involvement of mDia1 formin, a downstream target of Rho and a potent activator of actin polymerization; moreover, constitutively active mDia1, in and of itself, was sufficient for Golgi dispersion. The dispersion process was accompanied by formation of dynamic F-actin patches in the Golgi area. Experiments with cytoskeletal inhibitors (e.g., latrunculin B, blebbistatin, and Taxol) revealed that actin polymerization, myosin-II–driven contractility, and microtubule-based intracellular movement were all involved in the process of Golgi dispersion induced by Rho–mDia1 activation. Live imaging of Golgi recovery revealed that fusion of the small Golgi stacks into larger compartments was repressed in cells with active mDia1. Furthermore, the formation of Rab6-positive transport vesicles derived from the Golgi complex was enhanced upon activation of the Rho–mDia1 pathway. Transient localization of mDia1 to Rab6-positive vesicles was detected in cells expressing active RhoA. Thus, the Rho–mDia1 pathway is involved in regulation of the Golgi structure, affecting remodeling of Golgi membranes.
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Affiliation(s)
- Yuliya Zilberman
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
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21
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Structural organization of the Golgi apparatus. Curr Opin Cell Biol 2011; 23:85-93. [DOI: 10.1016/j.ceb.2010.10.004] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2010] [Revised: 10/07/2010] [Accepted: 10/17/2010] [Indexed: 11/21/2022]
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22
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Intracellular Movements: Integration at the Cellular Level as Reflected in the Organization of Organelle Movements. MECHANICAL INTEGRATION OF PLANT CELLS AND PLANTS 2011. [DOI: 10.1007/978-3-642-19091-9_4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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23
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Tan SC, Scherer J, Vallee RB. Recruitment of dynein to late endosomes and lysosomes through light intermediate chains. Mol Biol Cell 2010; 22:467-77. [PMID: 21169557 PMCID: PMC3038645 DOI: 10.1091/mbc.e10-02-0129] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Cytoplasmic dynein is involved in a wide range of cellular processes, but how it is regulated and how it recognizes an extremely wide range of cargo are incompletely understood. The dynein light intermediate chains, LIC1 and LIC2 (DYNC1LI1 and DYNC1LI2, respectively), have been implicated in cargo binding, but their full range of functions is unknown. Using LIC isoform-specific antibodies, we report the first characterization of their subcellular distribution and identify a specific association with elements of the late endocytic pathway, but not other vesicular compartments. LIC1 and LIC2 RNA interference (RNAi) each specifically disrupts the distribution of lysosomes and late endosomes. Stimulation of dynein-mediated late-endosomal transport by the Rab7-interacting lysosomal protein (RILP) is reversed by LIC1 RNAi, which displaces dynein, but not dynactin, from these structures. Conversely, expression of ΔN-RILP or the dynactin subunit dynamitin each fails to displace dynein, but not dynactin. Thus, using a variety of complementary approaches, our results indicate a novel specific role for the LICs in dynein recruitment to components of the late endocytic pathway.
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Affiliation(s)
- Serena C Tan
- Department of Pathology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
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24
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Rab11-FIP3 binds dynein light intermediate chain 2 and its overexpression fragments the Golgi complex. Biochem Biophys Res Commun 2010; 394:387-92. [DOI: 10.1016/j.bbrc.2010.03.028] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Accepted: 03/04/2010] [Indexed: 01/06/2023]
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25
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Horgan CP, Hanscom SR, Jolly RS, Futter CE, McCaffrey MW. Rab11-FIP3 links the Rab11 GTPase and cytoplasmic dynein to mediate transport to the endosomal-recycling compartment. J Cell Sci 2010; 123:181-91. [DOI: 10.1242/jcs.052670] [Citation(s) in RCA: 147] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Several protein families control intracellular transport processes in eukaryotic cells. Here, we show that the Rab11 GTPase effector protein Rab11-FIP3 (henceforth, FIP3) directly interacts with the dynein light intermediate chain 1 (DLIC-1, gene symbol DYNC1LI1) subunit of the cytoplasmic dynein 1 motor protein complex. We show that Rab11a, FIP3 and DLIC-1 form a ternary complex and that DLIC-1 colocalises with endogenous FIP3 and Rab11a in A431 cells. We demonstrate that association between FIP3 and DLIC-1 at the cell periphery precedes minus-end-directed microtubule-based transport, that FIP3 recruits DLIC-1 onto membranes, and that knockdown of DLIC-1 inhibits pericentrosomal accumulation of key endosomal-recycling compartment (ERC) proteins. In addition, we demonstrate that expression of a DLIC-1-binding truncation mutant of FIP3 disrupts the ability of ERC proteins to accumulate pericentrosomally. On the basis of these and other data, we propose that FIP3 links the Rab11 GTPase and cytoplasmic dynein to mediate transport of material from peripheral sorting endosomes to the centrally located ERC.
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Affiliation(s)
- Conor P. Horgan
- Molecular Cell Biology Laboratory, Department of Biochemistry, Biosciences Institute, University College Cork, Cork, Ireland
| | - Sara R. Hanscom
- Molecular Cell Biology Laboratory, Department of Biochemistry, Biosciences Institute, University College Cork, Cork, Ireland
| | - Rushee S. Jolly
- Division of Cell Biology, Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Clare E. Futter
- Division of Cell Biology, Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Mary W. McCaffrey
- Molecular Cell Biology Laboratory, Department of Biochemistry, Biosciences Institute, University College Cork, Cork, Ireland
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26
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Wei L, Zhang W, Liu Z, Li Y. AtKinesin-13A is located on Golgi-associated vesicle and involved in vesicle formation/budding in Arabidopsis root-cap peripheral cells. BMC PLANT BIOLOGY 2009; 9:138. [PMID: 19939242 PMCID: PMC2790454 DOI: 10.1186/1471-2229-9-138] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2009] [Accepted: 11/25/2009] [Indexed: 05/17/2023]
Abstract
BACKGROUND AtKinesin-13A is an internal-motor kinesin from Arabidopsis (Arabidopsis thaliana). Previous immunofluorescent results showed that AtKinesin-13A localized to Golgi stacks in plant cells. However, its precise localization and biological function in Golgi apparatus is unclear. RESULTS In this paper, immunofluorescent labeling and confocal microscopic observation revealed that AtKinesin-13A was co-localized with Golgi stacks in Arabidopsis root tip cells. Immuno-electron microscopic observations indicated that AtKinesin-13A is primarily localized on Golgi-associated vesicles in Arabidopsis root-cap cells. By T-DNA insertion, the inactivation of the AtKinesin-13A gene (NM-112536) resulted in a sharp decrease of size and number of Golgi vesicles in root-cap peripheral cells. At the same time, these cells were vacuolated in comparison to the corresponding cells of the wild type. CONCLUSION These results suggest that AtKinesin-13A decorates Golgi-associated vesicles and may be involved in regulating the formation of Golgi vesicles in the root-cap peripheral cells in Arabidopsis.
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Affiliation(s)
- Liqin Wei
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, PR China
- Research Center of Molecular and Developmental Biology, Key Laboratory of Photosynthesis and Environmental Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, PR China
| | - Wei Zhang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, PR China
| | - Zhaohui Liu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, PR China
| | - Yan Li
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, PR China
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27
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Jamal BT, Nita-Lazar M, Gao Z, Amin B, Walker J, Kukuruzinska MA. N-glycosylation status of E-cadherin controls cytoskeletal dynamics through the organization of distinct β-catenin- and γ-catenin-containing AJs. ACTA ACUST UNITED AC 2009; 2009:67-80. [PMID: 20502620 DOI: 10.2147/chc.s5965] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
N-glycosylation of E-cadherin has been shown to inhibit cell-cell adhesion. Specifically, our recent studies have provided evidence that the reduction of E-cadherin N-glycosylation promoted the recruitment of stabilizing components, vinculin and serine/threonine protein phosphatase 2A (PP2A), to adherens junctions (AJs) and enhanced the association of AJs with the actin cytoskeleton. Here, we examined the details of how N-glycosylation of E-cadherin affected the molecular organization of AJs and their cytoskeletal interactions. Using the hypoglycosylated E-cadherin variant, V13, we show that V13/β-catenin complexes preferentially interacted with PP2A and with the microtubule motor protein dynein. This correlated with dephosphorylation of the microtubule-associated protein tau, suggesting that increased association of PP2A with V13-containing AJs promoted their tethering to microtubules. On the other hand V13/γ-catenin complexes associated more with vinculin, suggesting that they mediated the interaction of AJs with the actin cytoskeleton. N-glycosylation driven changes in the molecular organization of AJs were physiologically significant because transfection of V13 into A253 cancer cells, lacking both mature AJs and tight junctions (TJs), promoted the formation of stable AJs and enhanced the function of TJs to a greater extent than wild-type E-cadherin. These studies provide the first mechanistic insights into how N-glycosylation of E-cadherin drives changes in AJ composition through the assembly of distinct β-catenin- and γ-catenin-containing scaffolds that impact the interaction with different cytoskeletal components.
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Affiliation(s)
- Basem T Jamal
- Department of Molecular and Cell Biology, Boston University Medical Center, Boston, MA, USA
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28
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Miller PM, Folkmann AW, Maia ARR, Efimova N, Efimov A, Kaverina I. Golgi-derived CLASP-dependent microtubules control Golgi organization and polarized trafficking in motile cells. Nat Cell Biol 2009; 11:1069-80. [PMID: 19701196 PMCID: PMC2748871 DOI: 10.1038/ncb1920] [Citation(s) in RCA: 230] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2008] [Accepted: 05/22/2009] [Indexed: 01/10/2023]
Abstract
Microtubules are indispensable for Golgi complex assembly and maintenance, which are integral parts of cytoplasm organization during interphase in mammalian cells. Here, we show that two discrete microtubule subsets drive two distinct, yet simultaneous, stages of Golgi assembly. In addition to the radial centrosomal microtubule array, which positions the Golgi in the centre of the cell, we have identified a role for microtubules that form at the Golgi membranes in a manner dependent on the microtubule regulators CLASPs. These Golgi-derived microtubules draw Golgi ministacks together in tangential fashion and are crucial for establishing continuity and proper morphology of the Golgi complex. We propose that specialized functions of these two microtubule arrays arise from their specific geometries. Further, we demonstrate that directional post-Golgi trafficking and cell migration depend on Golgi-associated CLASPs, suggesting that correct organization of the Golgi complex by microtubules is essential for cell polarization and motility.
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Affiliation(s)
- Paul M Miller
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
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29
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Kang BH, Staehelin LA. ER-to-Golgi transport by COPII vesicles in Arabidopsis involves a ribosome-excluding scaffold that is transferred with the vesicles to the Golgi matrix. PROTOPLASMA 2008; 234:51-64. [PMID: 18810574 DOI: 10.1007/s00709-008-0015-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2008] [Accepted: 08/04/2008] [Indexed: 05/02/2023]
Abstract
Plant Golgi stacks are mobile organelles that can travel along actin filaments. How COPII (coat complex II) vesicles are transferred from endoplasmic reticulum (ER) export sites to the moving Golgi stacks is not understood. We have examined COPII vesicle transfer in high-pressure frozen/freeze-substituted plant cells by electron tomography. Formation of each COPII vesicle is accompanied by the assembly of a ribosome-excluding scaffold layer that extends approximately 40 nm beyond the COPII coat. These COPII scaffolds can attach to the cis-side of the Golgi matrix, and the COPII vesicles are then transferred to the Golgi together with their scaffolds. When Atp115-GFP, a green fluorescent protein (GFP) fusion protein of an Arabidopsis thaliana homolog of the COPII vesicle-tethering factor p115, was expressed, the GFP localized to the COPII scaffold and to the cis-side of the Golgi matrix. Time-lapse imaging of Golgi stacks in live root meristem cells demonstrated that the Golgi stacks alternate between phases of fast, linear, saltatory movements (0.9-1.25 microm/s) and slower, wiggling motions (<0.4 microm/s). In root meristem cells, approximately 70% of the Golgi stacks were connected to an ER export site via a COPII scaffold, and these stacks possessed threefold more COPII vesicles than the Golgi not associated with the ER; in columella cells, only 15% of Golgi stacks were located in the vicinity of the ER. We postulate that the COPII scaffold first binds to and then fuses with the cis-side of the Golgi matrix, transferring its enclosed COPII vesicle to the cis-Golgi.
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Affiliation(s)
- Byung-Ho Kang
- Department of Molecular Cellular and Developmental Biology, University of Colorado at Boulder, Boulder, CO 80309, USA.
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30
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Zhou L, Chan WK, Xu N, Xiao K, Luo H, Luo KQ, Chang DC. Tanshinone IIA, an isolated compound from Salvia miltiorrhiza Bunge, induces apoptosis in HeLa cells through mitotic arrest. Life Sci 2008; 83:394-403. [PMID: 18721815 DOI: 10.1016/j.lfs.2008.07.011] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2007] [Revised: 06/27/2008] [Accepted: 07/04/2008] [Indexed: 10/21/2022]
Abstract
AIMS Tanshinone IIA (Tan IIA) is a compound isolated from Salvia miltiorrhiza Bunge (Danshen). The aim of this study is to investigate the mechanisms of its anti-cancer effect. MAIN METHODS To clearly delineate the cell cycle-dependent effects of Tan IIA, we used either synchronized cells or single living cell analysis to conduct our studies. Subcellular fractionation, Western blot analysis, immuno-fluorescence staining and FACS analysis were also employed in our study. KEY FINDINGS We found that Tan IIA could arrest cancer cells in mitosis by disrupting the mitotic spindle and subsequently triggered cells to enter apoptosis through the mitochondria-dependent apoptotic pathway. Thus, Tan IIA could selectively kill mitotic cells over interphase cells. In comparison with other existing anti-cancer drugs that cause mitotic arrest by interfering with the microtubule structure (such as vincristine or taxol), Tan IIA destroyed only the mitotic spindle during the M phase but not the microtubule structure in interphase cells. Furthermore, Tan IIA could trigger the mitotic arrested cells to enter apoptosis faster than vincristine or taxol. SIGNIFICANCE Since Tan IIA can selectively induce cancer cells to enter apoptosis through mitotic arrest, it has the potential to be developed into an anti-cancer drug.
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Affiliation(s)
- Lingli Zhou
- Department of Biology, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
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31
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Iyadurai SJP, Robinson JT, Ma L, He Y, Mische S, Li MG, Brown W, Guichard A, Bier E, Hays TS. Dynein and Star interact in EGFR signaling and ligand trafficking. J Cell Sci 2008; 121:2643-51. [PMID: 18653542 DOI: 10.1242/jcs.027144] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Intracellular transport and processing of ligands is critical to the activation of signal transduction pathways that guide development. Star is an essential gene in Drosophila that has been implicated in the trafficking of ligands for epidermal growth factor (EGF) receptor signaling. The role of cytoplasmic motors in the endocytic and secretory pathways is well known, but the specific requirement of motors in EGF receptor transport has not been investigated. We identified Star in a screen designed to recover second-site modifiers of the dominant rough eye phenotype of the Glued mutation Gl(1). The Glued (Gl) locus encodes the p150 subunit of the dynactin complex, an activator of cytoplasmic dynein-driven motility. We show that alleles of Gl and dynein genetically interact with both Star and EGFR alleles. Similarly to mutations in Star, the Gl(1) mutation is capable of modifying the phenotypes of the EGFR mutation Ellipse. These genetic interactions suggest a model in which Star, dynactin and dynein cooperate in the trafficking of EGF ligands. In support of this model, overexpression of the cleaved, active Spitz ligand can partially bypass defective trafficking and suppress the genetic interactions. Our direct observations of live S2 cells show that export of Spitz-GFP from the endoplasmic reticulum, as well as the trafficking of Spitz-GFP vesicles, depends on both Star and dynein.
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Affiliation(s)
- Stanley J P Iyadurai
- University of Minnesota, Department of Genetics, Cell Biology and Development, Minneapolis, MN 55455, USA
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32
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Maier KC, Godfrey JE, Echeverri CJ, Cheong FKY, Schroer TA. Dynamitin mutagenesis reveals protein-protein interactions important for dynactin structure. Traffic 2008; 9:481-91. [PMID: 18182012 PMCID: PMC4157825 DOI: 10.1111/j.1600-0854.2008.00702.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Dynactin is a highly conserved, multiprotein complex that works in conjunction with microtubule-based motors to power a variety of intracellular motile events. Dynamitin (p50) is a core element of dynactin structure. In the present study, we use targeted mutagenesis to evaluate how dynamitin's different structural domains contribute to its ability to self-associate, interact with dynactin and assemble into a complex with its close binding partner, p24. We show that these interactions involve three distinct structural elements: (i) a previously unidentified dimerization motif in the N-terminal 100 amino acids, (ii) an alpha-helical motif spanning aa 106-162 and (iii) the C-terminal half of the molecule (aa 213-406), which is predicted to fold into an antiparallel alpha-helix bundle. The N-terminal half of dynamitin by itself is sufficient to disrupt dynactin, although very high concentrations are required. The ability of mutations in dynamitin's interaction domains to disrupt dynactin in vitro was found to correlate with their inhibitory effects when expressed in cells. We determined that the dynactin subunit, p24, governs dynamitin oligomerization by binding dynamitin along its length. This suppresses aberrant multimerization and drives formation of a protein complex that is identical to the native dynactin shoulder.
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Affiliation(s)
- Kerstin C Maier
- Department of Biology, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA
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To C, Kulkarni S, Pawson T, Honda T, Gribble GW, Sporn MB, Wrana JL, Di Guglielmo GM. The synthetic triterpenoid 2-cyano-3,12-dioxooleana-1,9-dien-28-oic acid-imidazolide alters transforming growth factor beta-dependent signaling and cell migration by affecting the cytoskeleton and the polarity complex. J Biol Chem 2008; 283:11700-13. [PMID: 18283107 DOI: 10.1074/jbc.m704064200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The anti-tumor synthetic triterpenoid 2-cyano-3,12-dioxooleana-1,9-dien-28-oic acid (CDDO)-imidazolide (CDDO-Im) ectopically activates the transforming growth factor beta (TGFbeta)-Smad pathway and extends the duration of signaling by an undefined mechanism. Here we show that CDDO-Imdependent persistence of Smad2 phosphorylation is independent of Smad2 phosphatase activity and correlates with delayed TGFbeta receptor degradation and trafficking. Altered TGFbeta trafficking parallels the dispersal of EEA1-positive endosomes from the perinuclear region of CDDO-Im-treated cells. The effect of CDDO-Im on the EEA1 compartment led to an analysis of the cytoskeleton, and we observed that CDDO-Im alters microtubule dynamics by disrupting the microtubule-capping protein, Clip-170. Interestingly, biotinylated triterpenoid was found to localize to the polarity complex at the leading edge of migrating cells. Furthermore, CDDO-Im disrupted the localization of IQGAP1, PKCzeta, Par6, and TGFbeta receptors from the leading edge of migrating cells and inhibited TGFbeta-dependent cell migration. Thus, the synthetic triterpenoid CDDO-Im interferes with TGFbeta receptor trafficking and turnover and disrupts cell migration by severing the link between members of the polarity complex and the microtubule network.
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Affiliation(s)
- Ciric To
- Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario N6A 5C1, Canada
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34
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Rismanchi N, Soderblom C, Stadler J, Zhu PP, Blackstone C. Atlastin GTPases are required for Golgi apparatus and ER morphogenesis. Hum Mol Genet 2008; 17:1591-604. [PMID: 18270207 DOI: 10.1093/hmg/ddn046] [Citation(s) in RCA: 162] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The hereditary spastic paraplegias (SPG1-33) comprise a cluster of inherited neurological disorders characterized principally by lower extremity spasticity and weakness due to a length-dependent, retrograde axonopathy of corticospinal motor neurons. Mutations in the gene encoding the large oligomeric GTPase atlastin-1 are responsible for SPG3A, a common autosomal dominant hereditary spastic paraplegia. Here we describe a family of human GTPases, atlastin-2 and -3 that are closely related to atlastin-1. Interestingly, while atlastin-1 is predominantly localized to vesicular tubular complexes and cis-Golgi cisternae, mostly in brain, atlastin-2 and -3 are localized to the endoplasmic reticulum (ER) and are most enriched in other tissues. Knockdown of atlastin-2 and -3 levels in HeLa cells using siRNA (small interfering RNA) causes disruption of Golgi morphology, and these Golgi structures remain sensitive to brefeldin A treatment. Interestingly, expression of SPG3A mutant or dominant-negative atlastin proteins lacking GTPase activity causes prominent inhibition of ER reticularization, suggesting a role for atlastin GTPases in the formation of three-way junctions in the ER. However, secretory pathway trafficking as assessed using vesicular stomatitis virus G protein fused to green fluorescent protein (VSVG-GFP) as a reporter was essentially normal in both knockdown and dominant-negative overexpression conditions for all atlastins. Thus, the atlastin family of GTPases functions prominently in both ER and Golgi morphogenesis, but they do not appear to be required generally for anterograde ER-to-Golgi trafficking. Abnormal morphogenesis of the ER and Golgi resulting from mutations in atlastin-1 may ultimately underlie SPG3A by interfering with proper membrane distribution or polarity of the long corticospinal motor neurons.
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Affiliation(s)
- Neggy Rismanchi
- Cellular Neurology Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
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Motil J, Dubey M, Chan WKH, Shea TB. Inhibition of dynein but not kinesin induces aberrant focal accumulation of neurofilaments within axonal neurites. Brain Res 2007; 1164:125-31. [PMID: 17640622 DOI: 10.1016/j.brainres.2006.09.108] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2006] [Revised: 09/29/2006] [Accepted: 09/30/2006] [Indexed: 01/25/2023]
Abstract
Studies from several laboratories indicate that the microtubule motors kinesin and dynein respectively participate in anterograde and retrograde axonal transport of neurofilaments. Inhibition of dynein function by transfection with a construct expressing dynamitin or intracellular delivery of anti-dynein antibodies accelerates anterograde transport, which has been interpreted to indicate that the opposing action of both motors mediates the normal distribution of neurofilaments along axons. Herein, we demonstrate that, while expression of relatively low levels of exogenous dynamitin indeed accelerated anterograde neurofilament transport along axonal neurites in culture, expression of progressively increasing levels of dynamitin induced focal accumulation of neurofilaments within axonal neurites and eventually caused neurite retraction. Inhibition of kinesin inhibited anterograde transport, but did not induce similar focal accumulations. These findings are consistent with studies indicating that perturbations in dynein activity can contribute to the aberrant accumulations of neurofilaments that accompany ALS/motor neuron disease.
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Affiliation(s)
- Jennifer Motil
- Center for Cellular Neurobiology and Neurodegeneration Research, Department of Biological Sciences, University of Massachusetts Lowell, One University Avenue, Lowell, MA 01854, USA
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36
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Hirosue S, Senn K, Clément N, Nonnenmacher M, Gigout L, Linden RM, Weber T. Effect of inhibition of dynein function and microtubule-altering drugs on AAV2 transduction. Virology 2007; 367:10-8. [PMID: 17588632 PMCID: PMC2099573 DOI: 10.1016/j.virol.2007.05.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2007] [Revised: 02/12/2007] [Accepted: 05/02/2007] [Indexed: 11/28/2022]
Abstract
Over the past decade, adeno-associated (AAV) virus has emerged as an important vector for gene therapy. As a result, understanding its basic biology, including intracellular trafficking, has become increasingly important. Here, we describe the effect of inhibiting dynein function or altering the state of microtubule polymerization on rAAV2 transduction. Overexpression of dynamitin, resulting in a functional inhibition of the minus-end-directed microtubule motor protein dynein, did not inhibit transduction. Equally, treatment of cells with nocodazole, or concentrations of vinblastine that result in the disruption of microtubules, had no significant effect on transduction. In contrast, high concentrations of Taxol and vinblastine, resulting in microtubule stabilization and the formation of tubulin paracrystals respectively, reduced rAAV2 transduction in a vector-dose-dependent manner. These results demonstrate that AAV2 can infect HeLa cells independently of dynein function or an intact microtubule network.
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Affiliation(s)
- Sachiko Hirosue
- Department of Gene and Cell Medicine, Mount Sinai School of Medicine, New York, NY 10029
| | - Karin Senn
- Department of Gene and Cell Medicine, Mount Sinai School of Medicine, New York, NY 10029
| | - Nathalie Clément
- Department of Gene and Cell Medicine, Mount Sinai School of Medicine, New York, NY 10029
| | - Mathieu Nonnenmacher
- Department of Gene and Cell Medicine, Mount Sinai School of Medicine, New York, NY 10029
| | - Laure Gigout
- Department of Gene and Cell Medicine, Mount Sinai School of Medicine, New York, NY 10029
| | - R. Michael Linden
- Department of Gene and Cell Medicine, Mount Sinai School of Medicine, New York, NY 10029
- Department of Microbiology, Mount Sinai School of Medicine, New York, NY 10029
| | - Thomas Weber
- Department of Gene and Cell Medicine, Mount Sinai School of Medicine, New York, NY 10029
- Department of Molecular, Cell and Developmental Biology, Mount Sinai School of Medicine, New York, NY 10029
- Correspondence should be addressed to T.W. 1 Gustave L. Levy Place, Box 1496, New York, New York 10029-6514, Tel. 1-212-659-8293; Fax. 1-212-849-2437; E-mail:
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Kim HS, Takahashi M, Matsuo K, Ono Y. Recruitment of CG-NAP to the Golgi apparatus through interaction with dynein-dynactin complex. Genes Cells 2007; 12:421-34. [PMID: 17352745 DOI: 10.1111/j.1365-2443.2007.01055.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The structural organization and position of the Golgi apparatus are highly regulated by microtubule cytoskeleton and microtubule motor proteins. The mechanisms linking these proteins to the Golgi apparatus remain elusive. Here, we found that centrosome and Golgi-localized PKN associated protein (CG-NAP) was localized to the Golgi apparatus in a microtubule-dependent manner. Microtubule-binding experiments revealed that CG-NAP possessed two microtubule-binding domains. We also found that CG-NAP was well co-localized with cytoplasmic dynein subunits during recovery from the on-ice treatment of cells that induced dissociation of CG-NAP from the Golgi. Similar co-localization was observed during recovery from the acetate treatment, which has been reported to inhibit the dynein-mediated transport. CG-NAP was co-immunoprecipitated with a dynactin subunit p150(Glued). Expressing the p150(Glued)-binding region of CG-NAP fused with mitochondria-targeting sequence induced recruitment of mitochondria to the pericentriolar area, suggesting that this region interacts with functional cytoplasmic dynein in vivo. Moreover, over-expression of this region caused fragmentation of the Golgi similar to that of dynamitin. These results suggest that CG-NAP is recruited to the minus ends of microtubules by interacting with cytoplasmic dynein, thereby localizes to the Golgi apparatus in a microtubule-dependent manner and possibly involved in the formation of the Golgi near the centrosomes.
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Affiliation(s)
- Hon-Song Kim
- Graduate School of Science and Technology, Kobe University, Kobe 657-8501, Japan
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38
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Abstract
The dynamics of axonal transport are often colloquially described using highway traffic as a model system. Examination of the physics of traffic patterns, with emphasis on traffic jams and accidents, provides unique and perhaps counterintuitive insight into the aberrant accumulation of neurofilaments that accompanies amyotrophic lateral sclerosis/motor neuron disease.
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Affiliation(s)
- Thomas B Shea
- Center for Cellular Neurobiology and Neurodegeneration Research, Department of Biological Sciences, University of Massachusetts Lowell, Lowell, MA 01854, USA.
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39
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Fink G, Steinberg G. Dynein-dependent motility of microtubules and nucleation sites supports polarization of the tubulin array in the fungus Ustilago maydis. Mol Biol Cell 2006; 17:3242-53. [PMID: 16672380 PMCID: PMC1483053 DOI: 10.1091/mbc.e05-12-1118] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Microtubules (MTs) are often organized by a nucleus-associated MT organizing center (MTOC). In addition, in neurons and epithelial cells, motor-based transport of assembled MTs determines the polarity of the MT array. Here, we show that MT motility participates in MT organization in the fungus Ustilago maydis. In budding cells, most MTs are nucleated by three to six small and motile gamma-tubulin-containing MTOCs at the boundary of mother and daughter cell, which results in a polarized MT array. In addition, free MTs and MTOCs move rapidly throughout the cytoplasm. Disruption of MTs with benomyl and subsequent washout led to an equal distribution of the MTOC and random formation of highly motile and randomly oriented MTs throughout the cytoplasm. Within 3 min after washout, MTOCs returned to the neck region and the polarized MT array was reestablished. MT motility and polarity of the MT array was lost in dynein mutants, indicating that dynein-based transport of MTs and MTOCs polarizes the MT cytoskeleton. Observation of green fluorescent protein-tagged dynein indicated that this is achieved by off-loading dynein from the plus-ends of motile MTs. We propose that MT organization in U. maydis involves dynein-mediated motility of MTs and nucleation sites.
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Affiliation(s)
- Gero Fink
- Max-Planck-Institut für terrestrische Mikrobiologie, D-35043 Marburg, Germany
| | - Gero Steinberg
- Max-Planck-Institut für terrestrische Mikrobiologie, D-35043 Marburg, Germany
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40
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Wei L, Liu B, Li Y. Distribution of a kinesin-related protein on Golgi apparatus of tobacco pollen tubes. CHINESE SCIENCE BULLETIN-CHINESE 2005. [DOI: 10.1007/bf03182668] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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41
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Jiang S, Storrie B. Cisternal rab proteins regulate Golgi apparatus redistribution in response to hypotonic stress. Mol Biol Cell 2005; 16:2586-96. [PMID: 15758030 PMCID: PMC1087260 DOI: 10.1091/mbc.e04-10-0861] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
We show that a physiological role of the extensively studied cisternal Golgi rab protein, rab6, is modulation of Golgi apparatus response to stress. Taking exposure of cells to hypotonic media as the best-known example of mammalian Golgi stress response, we found that hypotonic-induced tubule extension from the Golgi apparatus was sensitive to GDP-rab6a expression. Similarly, we found that Golgi tubulation induced by brefeldin A, a known microtubule-dependent process, was inhibited by GDP-restricted rab6a, rab6a', and rab33b, the most commonly studied cisternal rab proteins. These GDP-rab levels were sufficient to inhibit rab-induced redistribution of Golgi glycosyltransferases into the endoplasmic reticulum (ER), also a microtubule-dependent process, and to depress Golgi membrane association of the GTP-conformer of rab6. Nocodazole-induced Golgi scattering, a microtubule-independent process, also was inhibited by GDP-rab6a expression. In comparison, we found similar GDP-rab expression levels had little inhibitory effect on another microtubule-independent process, constitutive recycling of Golgi resident proteins to the ER. We conclude that Golgi cisternal rabs, and in particular rab6a, are regulators of the Golgi response to stress and presumably the molecular targets of stress-activated signaling pathway(s). Moreover, we conclude that rab6a can regulate select microtubule-independent processes as well as microtubule-dependent processes.
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Affiliation(s)
- Shu Jiang
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
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42
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Papoulas O, Hays TS, Sisson JC. The golgin Lava lamp mediates dynein-based Golgi movements during Drosophila cellularization. Nat Cell Biol 2004; 7:612-8. [PMID: 15908943 DOI: 10.1038/ncb1264] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2005] [Accepted: 05/03/2005] [Indexed: 01/16/2023]
Abstract
Drosophila melanogaster cellularization is a dramatic form of cytokinesis in which a membrane furrow simultaneously encapsulates thousands of cortical nuclei of the syncytial embryo to generate a polarized cell layer. Formation of this cleavage furrow depends on Golgi-based secretion and microtubules. During cellularization, specific Golgi move along microtubules, first to sites of furrow formation and later to accumulate within the apical cytoplasm of the newly forming cells. Here we show that Golgi movements and furrow formation depend on cytoplasmic dynein. Furthermore, we demonstrate that Lava lamp (Lva), a golgin protein that is required for cellularization, specifically associates with dynein, dynactin, cytoplasmic linker protein-190 (CLIP-190) and Golgi spectrin, and is required for the dynein-dependent targeting of the secretory machinery. The Lva domains that bind these microtubule-dependent motility factors inhibit Golgi movement and cellularization in a live embryo injection assay. Our results provide new evidence that golgins promote dynein-based motility of Golgi membranes.
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Affiliation(s)
- Ophelia Papoulas
- The Section of MCD Biology and the Institute for Cellular and Molecular Biology, The University of Texas at Austin, TX 78712, USA
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43
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Lewis ML. The cytoskeleton, apoptosis, and gene expression in T lymphocytes and other mammalian cells exposed to altered gravity. ADVANCES IN SPACE BIOLOGY AND MEDICINE 2003; 8:77-128. [PMID: 12951694 DOI: 10.1016/s1569-2574(02)08016-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Affiliation(s)
- Marian L Lewis
- Department of Biological Sciences, University of Alabama, Huntsville, AL 35899, USA
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44
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Abstract
The actin cytoskeleton and associated myosin motor proteins are essential for the transport and steady-state localization of vesicles and organelles and for the dynamic remodeling of the plasma membrane as well as for the maintenance of differentiated cell-surface structures. Myosin VI may be expected to have unique cellular functions, because it moves, unlike almost all other myosins, towards the minus end of actin filaments. Localization and functional studies indicate that myosin VI plays a role in a variety of different intracellular processes, such as endocytosis and secretion as well as cell migration. These diverse functions of myosin VI are mediated by interaction with a range of different binding partners.
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Affiliation(s)
- Folma Buss
- Cambridge Institute for Medical Research, University of Cambridge, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 2XY, UK.
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45
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Short B, Preisinger C, Schaletzky J, Kopajtich R, Barr FA. The Rab6 GTPase regulates recruitment of the dynactin complex to Golgi membranes. Curr Biol 2002; 12:1792-5. [PMID: 12401177 DOI: 10.1016/s0960-9822(02)01221-6] [Citation(s) in RCA: 168] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Dynactin is a multisubunit protein complex required for the activity of dynein in diverse intracellular motility processes, including membrane transport. Dynactin can bind to vesicles and liposomes containing acidic phospholipids, but general properties such as this are unlikely to explain the regulated recruitment of dynactin to specific sites on organelle membranes. Additional factors must therefore exist to control this process. Candidates for these factors are the Rab GTPases, which function in the tethering of vesicles to their target organelle prior to membrane fusion. In particular, Rab27a tethers melanosomes to the actin cytoskeleton. Other Rabs have been implicated in microtubule-dependent organelle motility; Rab7 controls lysosomal transport, and Rab6 is involved in microtubule-dependent transport pathways through the Golgi and from endosomes to the Golgi. We demonstrate that dynactin binds to Rab6 and shows a Rab6-dependent recruitment to Golgi membranes. Other Golgi Rabs do not bind to dynactin and are unable to support its recruitment to membranes. Rab6 therefore functions as a specificity or tethering factor controlling the recruitment of dynactin to membranes.
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Affiliation(s)
- Benjamin Short
- Department of Cell Biology, Max-Planck-Institute of Biochemistry, Martinsried, Germany
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46
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Burdett IDJ. Effects of Brefeldin A on disassembly of the Golgi body in MDCK cells subjected to a Ca2+ shift at low temperature. Eur J Cell Biol 2002; 81:525-8. [PMID: 12437186 DOI: 10.1078/0171-9335-00274] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
When Madin-Darby canine kidney (MDCK) cells were grown in low-Ca2+ medium (LCM) the trans-Golgi cisternae, like those of cells maintained in high-Ca2+ medium (HCM), showed discrete localization of reaction product after thiamine pyrophosphatase (TPPase) staining. After exposure to Brefeldin A (BFA, 5 microg/ml) in LCM at 19 degrees C, the Golgi body dispersed and reaction product was distributed to the nuclear envelope and endoplasmic reticulum. The Golgi body reassembled in cells shifted back to HCM at 37 degrees C, with or without BFA, suggesting that low temperature and LCM exert synergistic effects in aiding dispersal of the Golgi apparatus in the presence of BFA. However, these results appear to be more directly correlated with the lack of defined cell polarity. Cells in LCM are unpolarized and both the centrosomes and the Golgi body are sub-nuclear in position, in contrast to their location in HCM where both organelles lie above the nucleus. The effects of BFA on the disassembly of the Golgi body therefore suggest that MDCK cells grown in LCM at low temperature cells are comparable to those non-polarized cell lines that are sensitive to BFA.
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47
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Burdett IDJ, Sullivan KH. Desmosome assembly in MDCK cells: transport of precursors to the cell surface occurs by two phases of vesicular traffic and involves major changes in centrosome and Golgi location during a Ca(2+) shift. Exp Cell Res 2002; 276:296-309. [PMID: 12027459 DOI: 10.1006/excr.2002.5509] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Desmosome formation in MDCK cells was investigated using a Ca(2+) shift. Following preliminary treatment with cycloheximide at 37 degrees C, continued surface transport and subsequent endocytosis were minimized by incubating cells at 19 degrees C to trap nascent glycoproteins within the Golgi body. Release into high Ca(2+) medium (HCM) at 37 degrees C resulted in junction formation as well as relocation of the Golgi body and centrosomes to a subapical location. Desmosome formation occurred in two stages over 2 h, the first occurring within 30 min of the shift to HCM, in 60-nm vesicles containing chiefly Dsc2 and lower concentrations of Dsg and E-cadherin distributed to the entire cell surface. Much of this material was subsequently endocytosed. The second stage involved transport of Dsg, E-cadherin, plakoglobin, and beta-catenin, in more complex vesicles some 200 nm in size, directed to possible nucleation sites on the developing basolateral surface. Plaque proteins such as desmoplakin I/II were added subsequently. Stage-two vesicles, but possibly not those of stage one, were accessible to endocytic markers via retrograde transport from multivesicular bodies prelabeled at 19 degrees C.
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Affiliation(s)
- Ian D J Burdett
- Division of Membrane Biology, National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, United Kingdom.
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48
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Perez F, Pernet-Gallay K, Nizak C, Goodson HV, Kreis TE, Goud B. CLIPR-59, a new trans-Golgi/TGN cytoplasmic linker protein belonging to the CLIP-170 family. J Cell Biol 2002; 156:631-42. [PMID: 11854307 PMCID: PMC2174080 DOI: 10.1083/jcb.200111003] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
The microtubule cytoskeleton plays a fundamental role in cell organization and membrane traffic in higher eukaryotes. It is well established that molecular motors are involved in membrane-microtubule interactions, but it has also been proposed that nonmotor microtubule-binding (MTB) proteins known as CLIPs (cytoplasmic linker proteins) have basic roles in these processes. We report here the characterization of CLIPR-59, a CLIP-170-related protein localized to the trans-most part of the Golgi apparatus. CLIPR-59 contains an acidic region followed by three ankyrin-like repeats and two CLIP-170-related MTB motifs. We show that the 60-amino acid-long carboxy-terminal domain of CLIPR-59 is necessary and sufficient to achieve Golgi targeting, which represents the first identification of a membrane targeting domain in a CLIP-170-related protein. The MTB domain of CLIPR-59 is functional because it localizes to microtubules when expressed as a fragment in HeLa cells. However, our results suggest that this domain is normally inhibited by the presence of adjacent domains, because neither full-length CLIPR-59 nor a CLIPR-59 mutant missing its membrane-targeting region localize to microtubules. Consistent with this observation, overexpression of CLIPR-59 does not affect the microtubule network. However, CLIPR-59 overexpression strongly perturbs early/recycling endosome-TGN dynamics, implicating CLIPR-59 in the regulation of this pathway.
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Affiliation(s)
- Franck Perez
- Institut Curie, CNRS UMR144, 75248 Paris, France.
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49
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Jesch SA, Mehta AJ, Velliste M, Murphy RF, Linstedt AD. Mitotic Golgi is in a dynamic equilibrium between clustered and free vesicles independent of the ER. Traffic 2001; 2:873-84. [PMID: 11737825 DOI: 10.1034/j.1600-0854.2001.21203.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Golgi inheritance during cell division involves Golgi disassembly but it remains unclear whether the breakdown product is dispersed vesicles, clusters of vesicles or a fused ER/Golgi network. Evidence against the fused ER/Golgi hypothesis was previously obtained from subcellular fractionation studies, but left concerns about the means used to obtain and disrupt mitotic cells. Here, we performed velocity gradient analysis on otherwise untreated cells shaken from plates 9 h after release from an S-phase block. In addition, we used digitonin and freeze/thaw permeabilization as alternatives to mechanical homogenization. Under each of these conditions, approximately 75% of the Golgi was recovered in a population of small vesicles that lacked detectable ER. We also used multilabel fluorescent microscopy with optical sectioning by deconvolution to compare the 3D metaphase staining pattern of endogenous Golgi and ER markers. Although both ER and Golgi staining were primarily diffuse, only the ER was excluded from the mitotic spindle region. Surprisingly, only 2% of the Golgi fluorescence was present as resolvable structures previously characterized as vesicle clusters. These were not present in the ER pattern. Significantly, a portion of the diffuse Golgi fluorescence, presumably representing dispersed 60-nm vesicles, underwent an apparent rapid aggregation with the larger Golgi structures upon treatments that impaired microtubule integrity. Therefore, mitotic Golgi appears to be in a dynamic equilibrium between clustered and free vesicles, and accurate partitioning may be facilitated by microtubule-based motors acting on the clusters to insure random and uniform distribution of the vesicles.
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Affiliation(s)
- S A Jesch
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA
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50
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Lewis ML, Cubano LA, Zhao B, Dinh HK, Pabalan JG, Piepmeier EH, Bowman PD. cDNA microarray reveals altered cytoskeletal gene expression in space-flown leukemic T lymphocytes (Jurkat). FASEB J 2001; 15:1783-5. [PMID: 11481229 DOI: 10.1096/fj.00-0820fje] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- M L Lewis
- University of Alabama in Huntsville, Department of Biological Sciences, Huntsville, Alabama 35899, USA.
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