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Rao L, Gennerich A. Structure and Function of Dynein's Non-Catalytic Subunits. Cells 2024; 13:330. [PMID: 38391943 PMCID: PMC10886578 DOI: 10.3390/cells13040330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 02/05/2024] [Accepted: 02/09/2024] [Indexed: 02/24/2024] Open
Abstract
Dynein, an ancient microtubule-based motor protein, performs diverse cellular functions in nearly all eukaryotic cells, with the exception of land plants. It has evolved into three subfamilies-cytoplasmic dynein-1, cytoplasmic dynein-2, and axonemal dyneins-each differentiated by their cellular functions. These megadalton complexes consist of multiple subunits, with the heavy chain being the largest subunit that generates motion and force along microtubules by converting the chemical energy of ATP hydrolysis into mechanical work. Beyond this catalytic core, the functionality of dynein is significantly enhanced by numerous non-catalytic subunits. These subunits are integral to the complex, contributing to its stability, regulating its enzymatic activities, targeting it to specific cellular locations, and mediating its interactions with other cofactors. The diversity of non-catalytic subunits expands dynein's cellular roles, enabling it to perform critical tasks despite the conservation of its heavy chains. In this review, we discuss recent findings and insights regarding these non-catalytic subunits.
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Affiliation(s)
- Lu Rao
- Department of Biochemistry and Gruss Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Arne Gennerich
- Department of Biochemistry and Gruss Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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A role for Dynlt3 in melanosome movement, distribution, acidity and transfer. Commun Biol 2021; 4:423. [PMID: 33772156 PMCID: PMC7997999 DOI: 10.1038/s42003-021-01917-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 02/25/2021] [Indexed: 12/17/2022] Open
Abstract
Skin pigmentation is dependent on cellular processes including melanosome biogenesis, transport, maturation and transfer to keratinocytes. However, how the cells finely control these processes in space and time to ensure proper pigmentation remains unclear. Here, we show that a component of the cytoplasmic dynein complex, Dynlt3, is required for efficient melanosome transport, acidity and transfer. In Mus musculus melanocytes with decreased levels of Dynlt3, pigmented melanosomes undergo a more directional motion, leading to their peripheral location in the cell. Stage IV melanosomes are more acidic, but still heavily pigmented, resulting in a less efficient melanosome transfer. Finally, the level of Dynlt3 is dependent on β-catenin activity, revealing a function of the Wnt/β-catenin signalling pathway during melanocyte and skin pigmentation, by coupling the transport, positioning and acidity of melanosomes required for their transfer.
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Andrés-Benito P, Povedano M, Torres P, Portero-Otín M, Ferrer I. Altered Dynein Axonemal Assembly Factor 1 Expression in C-Boutons in Bulbar and Spinal Cord Motor-Neurons in Sporadic Amyotrophic Lateral Sclerosis. J Neuropathol Exp Neurol 2020; 78:416-425. [PMID: 30939186 DOI: 10.1093/jnen/nlz019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Dyneins are major components of microtubules. Dynein assembly is modulated by a heterogeneous group of dynein axonemal assembly factors (DNAAFs). The present study analyzes dynein axonemal assembly factor 1 (DNAAF1) and leucine-rich repeat-containing protein 50 (LRRC50), the corresponding encoded protein, in lower motor neurons in spinal cord of sALS postmortem samples and hSOD1-G93A transgenic mice compared with controls. DNAAF1 mRNA is significantly reduced in the anterior horn in sALS, and LRRC50 immunoreactivity is significantly reduced in C-boutons of the remaining motor neurons of the anterior horn, dorsal nucleus of the vagus nerve, and hypoglossal nuclei at terminal stages of ALS. LRRC50 immunoreactivity has a perinuclear distribution in motor neurons in sALS thus suggesting a disorder of transport. The number of LRRC50-/S1R-immunoreactive structures is also significantly decreased in hSOD1-G93A transgenic mice at the age of 90 days (preclinical stages), and the number of motor neurons with LRRC50-immunoreactive structures is significantly reduced in animals aged 150 days (clinical stages). These observations suggest cholinergic denervation of motor neurons as a pathogenic factor in motor neuron disease. LRRC50 protein levels were not detected in human CSF.
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Affiliation(s)
- Pol Andrés-Benito
- Department of Pathology and Experimental Therapeutics, University of Barcelona, Spain.,Institute Carlos III, Biomedical Network Research Center on Neurodegenerative Diseases (CIBERNED), Hospitalet de Llobregat, Spain.,Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat, Barcelona, Spain
| | - Mònica Povedano
- Functional Unit of Amyotrophic Lateral Sclerosis (UFELA), Service of Neurology, Bellvitge University Hospital, Hospitalet de Llobregat, Spain
| | - Pascual Torres
- Departament Medicina Experimental, Facultat de Medicina, Universitat de Lleida, IRBLLEIDA, Lleida, Spain
| | - Manuel Portero-Otín
- Departament Medicina Experimental, Facultat de Medicina, Universitat de Lleida, IRBLLEIDA, Lleida, Spain
| | - Isidro Ferrer
- Department of Pathology and Experimental Therapeutics, University of Barcelona, Spain.,Institute Carlos III, Biomedical Network Research Center on Neurodegenerative Diseases (CIBERNED), Hospitalet de Llobregat, Spain.,Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat, Barcelona, Spain.,Neuropathology, Pathologic Anatomy Service, Bellvitge University Hospital, IDIBELL, L'Hospitalet de Llobregat, Spain.,Institute of Neurosciences, University of Barcelona, Barcelona, Spain
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4
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Semerci F, Maletic-Savatic M. Transgenic mouse models for studying adult neurogenesis. ACTA ACUST UNITED AC 2016; 11:151-167. [PMID: 28473846 DOI: 10.1007/s11515-016-1405-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The mammalian hippocampus shows a remarkable capacity for continued neurogenesis throughout life. Newborn neurons, generated by the radial neural stem cells (NSCs), are important for learning and memory as well as mood control. During aging, the number and responses of NSCs to neurogenic stimuli diminish, leading to decreased neurogenesis and age-associated cognitive decline and psychiatric disorders. Thus, adult hippocampal neurogenesis has garnered significant interest because targeting it could be a novel potential therapeutic strategy for these disorders. However, if we are to use neurogenesis to halt or reverse hippocampal-related pathology, we need to understand better the core molecular machinery that governs NSC and their progeny. In this review, we summarize a wide variety of mouse models used in adult neurogenesis field, present their advantages and disadvantages based on specificity and efficiency of labeling of different cell types, and review their contribution to our understanding of the biology and the heterogeneity of different cell types found in adult neurogenic niches.
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Affiliation(s)
- Fatih Semerci
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA.,Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX 77030, USA
| | - Mirjana Maletic-Savatic
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA.,Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX 77030, USA.,Department of Pediatrics-Neurology, Department of Neuroscience, and Structural and Computational Biology and Molecular Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
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5
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Indu S, Sekhar SC, Sengottaiyan J, Kumar A, Pillai SM, Laloraya M, Kumar PG. Aberrant Expression of Dynein light chain 1 (DYNLT1) is Associated with Human Male Factor Infertility. Mol Cell Proteomics 2015; 14:3185-95. [PMID: 26432663 DOI: 10.1074/mcp.m115.050005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Indexed: 12/18/2022] Open
Abstract
DYNLT1 is a member of a gene family identified within the t-complex of the mouse, which has been linked with male germ cell development and function in the mouse and the fly. Though defects in the expression of this gene are associated with male sterility in both these models, there has been no study examining its association with spermatogenic defects in human males. In this study, we evaluated the levels of DYNLT1 and its expression product in the germ cells of fertile human males and males suffering from spermatogenic defects. We screened fertile (n = 14), asthenozoospermic (n = 15), oligozoospermic (n = 20) and teratozoospermic (n = 23) males using PCR and Western blot analysis. Semiquantitative PCR indicated either undetectable or significantly lower levels of expression of DYNLT1 in the germ cells from several patients from across the three infertility syndrome groups, when compared with that of fertile controls. DYNLT1 was localized on head, mid-piece, and tail segments of spermatozoa from fertile males. Spermatozoa from infertile males presented either a total absence of DYNLT1 or its absence in the tail region. Majority of the infertile individuals showed negligible levels of localization of DYNLT1 on the spermatozoa. Overexpression of DYNLT1 in GC1-spg cell line resulted in the up-regulation of several cytoskeletal proteins and molecular chaperones involved in cell cycle regulation. Defective expression of DYNLT1 was associated with male factor infertility syndromes in our study population. Proteome level changes in GC1-spg cells overexpressing DYNLT1 were suggestive of its possible function in germ cell development. We have discussed the implications of these observations in the light of the known functions of DYNLT1, which included protein trafficking, membrane vesiculation, cell cycle regulation, and stem cell differentiation.
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Affiliation(s)
- Sivankutty Indu
- From the ‡Rajiv Gandhi Centre for Biotechnology, Thycaud PO, Poojappura, Thiruvananthapuram 695 014, Kerala, India
| | - Sreeja C Sekhar
- From the ‡Rajiv Gandhi Centre for Biotechnology, Thycaud PO, Poojappura, Thiruvananthapuram 695 014, Kerala, India
| | - Jeeva Sengottaiyan
- From the ‡Rajiv Gandhi Centre for Biotechnology, Thycaud PO, Poojappura, Thiruvananthapuram 695 014, Kerala, India
| | - Anil Kumar
- From the ‡Rajiv Gandhi Centre for Biotechnology, Thycaud PO, Poojappura, Thiruvananthapuram 695 014, Kerala, India
| | - Sathy M Pillai
- §Dr. SathyPillai, Samad Hospital, V.V.Road, Pattoor, Thiruvananthapuram-695035. Kerala, India
| | - Malini Laloraya
- From the ‡Rajiv Gandhi Centre for Biotechnology, Thycaud PO, Poojappura, Thiruvananthapuram 695 014, Kerala, India
| | - Pradeep G Kumar
- From the ‡Rajiv Gandhi Centre for Biotechnology, Thycaud PO, Poojappura, Thiruvananthapuram 695 014, Kerala, India;
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Xu X, Zhang Q, Hu JY, Zhang DX, Jiang XP, Jia JZ, Zhu JC, Huang YS. Phosphorylation of DYNLT1 at serine 82 regulates microtubule stability and mitochondrial permeabilization in hypoxia. Mol Cells 2013; 36:322-32. [PMID: 24170091 PMCID: PMC3887991 DOI: 10.1007/s10059-013-0114-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 07/09/2013] [Accepted: 08/22/2013] [Indexed: 12/19/2022] Open
Abstract
Hypoxia-induced microtubule disruption and mitochondrial permeability transition (mPT) are crucial events leading to fatal cell damage and recent studies showed that microtubules (MTs) are involved in the modulation of mitochondrial function. Dynein light chain Tctex-type 1 (DYNLT1) is thought to be associated with MTs and mitochondria. Previously we demonstrated that DYNLT1 knockdown aggravates hypoxia-induced mitochondrial permeabilization, which indicates a role of DYNLT1 in hypoxic cytoprotection. But the underlying regulatory mechanism of DYNLT1 remains illusive. Here we aimed to investigate the phosphorylation alteration of DYNLT1 at serine 82 (S82) in hypoxia (1% O2). We therefore constructed recombinant adenoviruses to generate S82E and S82A mutants, used to transfect H9c2 and HeLa cell lines. Development of hypoxia-induced mPT (MMP examining, Cyt c release and mPT pore opening assay), hypoxic energy metabolism (cellular viability and ATP quantification), and stability of MTs were examined. Our results showed that phosph-S82 (S82-P) expression was increased in early hypoxia; S82E mutation (phosphomimic) aggravated mitochondrial damage, elevated the free tubulin in cytoplasm and decreased the cellular viability; S82A mutation (dephosphomimic) seemed to diminish the hypoxia-induced injury. These data suggest that DYNLT1 phosphorylation at S82 is involved in MTs and mitochondria regulation, and their interaction and cooperation contribute to the cellular hypoxic tolerance. Thus, we provide new insights into a DYNLT1 mechanism in stabilizing MTs and mitochondria, and propose a potential therapeutic target for hypoxia cytoprotective studies.
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Affiliation(s)
- Xue Xu
- School of Nursing, The Third Military Medical University, Chongqing, China
| | - Qiong Zhang
- Institute of Burn Research, State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, The Third Military Medical University, Chongqing 400038, China
| | - Jiong-yu Hu
- Institute of Burn Research, State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, The Third Military Medical University, Chongqing 400038, China
| | - Dong-xia Zhang
- Institute of Burn Research, State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, The Third Military Medical University, Chongqing 400038, China
| | - Xu-pin Jiang
- Institute of Burn Research, State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, The Third Military Medical University, Chongqing 400038, China
| | - jie-zhi Jia
- Institute of Burn Research, State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, The Third Military Medical University, Chongqing 400038, China
| | - Jing-ci Zhu
- School of Nursing, The Third Military Medical University, Chongqing, China
| | - Yue-sheng Huang
- Institute of Burn Research, State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, The Third Military Medical University, Chongqing 400038, China
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Toledo MAS, Favaro MTP, Alves RF, Santos CA, Beloti LL, Crucello A, Santiago AS, Mendes JS, Horta MAC, Aparicio R, Souza AP, Azzoni AR. Characterization of the human dynein light chain Rp3 and its use as a non-viral gene delivery vector. Appl Microbiol Biotechnol 2013; 98:3591-602. [PMID: 24077724 DOI: 10.1007/s00253-013-5239-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2013] [Revised: 08/30/2013] [Accepted: 09/04/2013] [Indexed: 12/01/2022]
Abstract
Dynein light chains mediate the interaction between the cargo and the dynein motor complex during retrograde microtubule-mediated transport in eukaryotic cells. In this study, we expressed and characterized the recombinant human dynein light chain Rp3 and developed a modified variant harboring an N-terminal DNA-binding domain (Rp3-Db). Our approach aimed to explore the retrograde cell machinery based on dynein to enhance plasmid DNA (pDNA) traffic along the cytosol toward the nucleus. In the context of non-viral gene delivery, Rp3-Db is expected to simultaneously interact with DNA and dynein, thereby enabling a more rapid and efficient transport of the genetic material across the cytoplasm. We successfully purified recombinant Rp3 and obtained a low-resolution structural model using small-angle X-ray scattering. Additionally, we observed that Rp3 is a homodimer under reducing conditions and remains stable over a broad pH range. The ability of Rp3 to interact with the dynein intermediate chain in vitro was also observed, indicating that the recombinant Rp3 is correctly folded and functional. Finally, Rp3-Db was successfully expressed and purified and exhibited the ability to interact with pDNA and mediate the transfection of cultured HeLa cells. Rp3-Db was also capable of interacting in vitro with dynein intermediate chains, indicating that the addition of the N-terminal DNA-binding domain does not compromise its function. The transfection level observed for Rp3-Db is far superior than that reported for protamine and is comparable to that of the cationic lipid Lipofectamine™. This report presents an initial characterization of a non-viral delivery vector based on the dynein light chain Rp3 and demonstrates the potential use of modified human light chains as gene delivery vectors.
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8
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Dhaliwal J, Lagace DC. Visualization and genetic manipulation of adult neurogenesis using transgenic mice. Eur J Neurosci 2011; 33:1025-36. [PMID: 21395845 DOI: 10.1111/j.1460-9568.2011.07600.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Many laboratories have focused efforts on the creation of transgenic mouse models to study adult neurogenesis. In the last decade several constitutive reporter, as well as inducible transgenic lines have been published that allowed for visualization, tracking and alteration of specific neurogenic cell populations in the adult brain. Given the popularity of this approach, multiple mouse lines are available, and this review summarizes the differences in the basic techniques that have been used to create these mice, highlighting the different constructs and reporter proteins used, as well as the strengths and limitations of each of these models. Representative examples from the literature demonstrate some of the diverse and seminal findings that have come to fruition through the laborious, yet highly rewarding work of creating transgenic mouse lines for adult neurogenesis research.
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Affiliation(s)
- Jagroop Dhaliwal
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
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Huang X, Wang HL, Qi ST, Wang ZB, Tong JS, Zhang QH, Ouyang YC, Hou Y, Schatten H, Qi ZQ, Sun QY. DYNLT3 is required for chromosome alignment during mouse oocyte meiotic maturation. Reprod Sci 2011; 18:983-9. [PMID: 21693773 DOI: 10.1177/1933719111401664] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Dynein light chain, Tctex-type 3 (DYNLT3), is a member of the cytoplasmic dynein DYNLT light chain family and has been reported to have a potential role in chromosome congression in human mitosis. However, its role in mammalian meiosis is unclear. In this study, we examined its localization, expression, and functions in mouse oocyte meiosis. Immunofluorescent staining showed that DYNLT3 was restricted to the germinal vesicle and associated with kinetochores at the germinal vesicle breakdown stage, metaphase I and metaphase II. The expression level of DYNLT3 was similar at all meiotic stages. Depletion of DYNLT3 by antibody injection resulted in chromosome misalignment and decrease of the polar body extrusion rate. We further found that DYNLT3-depleted oocytes displayed kinetochore-microtubule detachments. Chromosome-spread experiments showed that depletion of DYNLT3 inhibited the metaphase-anaphase transition by preventing homologous chromosome segregation in meiosis I. Our data suggest that DYNLT3 is required for chromosome alignment and homologous chromosome segregation during mouse oocyte meiosis.
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Affiliation(s)
- Xin Huang
- Organ Transplantation Institute, Xiamen University, Xiamen City, Fujian Province, China
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Tseng YY, Gruzdeva N, Li A, Chuang JZ, Sung CH. Identification of the Tctex-1 regulatory element that directs expression to neural stem/progenitor cells in developing and adult brain. J Comp Neurol 2010; 518:3327-42. [PMID: 20575070 DOI: 10.1002/cne.22402] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Previous studies showed that Tctex-1 immunoreactivity is selectively enriched in the germinal zones of adult brain. In this report we identify a regulatory region of the Tctex-1 gene that is capable of directing transgenic expression of green fluorescent protein (GFP) reporter that recapitulates the spatial and temporal expression pattern of endogenous Tctex-1. This construct specifically targeted expression to the nestin(+)/Pax6(+)/GLAST(+) radial glial cells and Tbr2(+) intermediate progenitors when the reporter construct was delivered to developing mouse neocortex via in utero electroporation. Characterization of mice transgenically expressing GFP under the same regulatory element showed that the GFP expression is faithful to endogenous Tctex-1 at the subgranular zone (SGZ) of dentate gyrus, ventricular/subventricular zone of lateral ventricles, and ependymal layer of 3rd ventricle of adult brains. Immunolocalization and bromodeoxyuridine incorporation studies of adult SGZ in four independent mouse lines showed that Tctex-1:GFP reporter selectively marks nestin(+)/GFAP(+)/Sox2(+) neural stem-like cells in two mouse lines (4 and 13). In two other mouse lines (17 and 18), Tctex-1:GFP is selectively expressed in Type-2 and Type-3 transient amplifying progenitors and a small subset of young neuronal progeny. The P/E-Tctex-1 reporter mouse studies independently confirmed the specific enrichment of Tctex-1 at adult SGZ stem/progenitor cells. Furthermore, these studies supported the notion that an analogous transcriptional program may be used to regulate neurogenesis in embryonic cerebral cortex and adult hippocampus. Finally, the genomic sequences and the reporter mouse lines described here provide useful experimental tools to advance adult neural stem cell research.
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Affiliation(s)
- Yun-Yu Tseng
- Margaret M. Dyson Vision Research Institute, Department of Ophthalmology, Weill Medical College of Cornell University, New York, New York 10065, USA
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Chuang JZ, Chou SY, Sung CH. Chloride intracellular channel 4 is critical for the epithelial morphogenesis of RPE cells and retinal attachment. Mol Biol Cell 2010; 21:3017-28. [PMID: 20610659 PMCID: PMC2929995 DOI: 10.1091/mbc.e09-10-0907] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
A plasmid-based transfection method was used to cell-autonomously silence chloride intracellular channel 4 (CLIC4) in RPE in situ. These results show CLIC4 is critical for epithelial morphogenesis and retinal attachment. Novel candidate targets for retinal detachment therapy have also been identified. Retinal detachment is a sight-threatening condition. The molecular mechanism underlying the adhesion between the RPE and photoreceptors is poorly understood because the intimate interactions between these two cell types are impossible to model and study in vitro. In this article, we show that chloride intracellular channel 4 (CLIC4) is enriched at apical RPE microvilli, which are interdigitated with the photoreceptor outer segment. We used a novel plasmid-based transfection method to cell-autonomously suppress CLIC4 in RPE in situ. CLIC4 silenced RPE cells exhibited a significant loss of apical microvilli and basal infoldings, reduced retinal adhesion, and epithelial-mesenchymal transition. Ectopically expressing ezrin failed to rescue the morphological changes exerted by CLIC4 silencing. Neural retinas adjacent to the CLIC4-suppressed RPE cells display severe dysplasia. Finally, a high level of aquaporin 1 unexpectedly appeared at the apical surfaces of CLIC4-suppressed RPE cells, together with a concomitant loss of basal surface expression of monocarboxylate transporter MCT3. Our results suggested that CLIC4 plays an important role in RPE-photoreceptor adhesion, perhaps by modulating the activity of cell surface channels/transporters. We propose that these changes may be attributable to subretinal fluid accumulation in our novel retinal detachment animal model.
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Affiliation(s)
- Jen-Zen Chuang
- Department of Ophthalmology, Weill Medical College of Cornell University, New York, NY 10021, USA
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12
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Sedmak T, Sehn E, Wolfrum U. Immunoelectron microscopy of vesicle transport to the primary cilium of photoreceptor cells. Methods Cell Biol 2009; 94:259-72. [PMID: 20362095 DOI: 10.1016/s0091-679x(08)94013-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Cilia are organelles of high structural complexity. Since the biosynthetic machinery is absent from cilia all their molecular components must be synthesized in organelles of the cytoplasm and subsequently transported to the cilium. Ciliary cargos are thought to be translocated in the membrane of transport vesicles or association with these vesicles to the base of the cilium where the vesicles fuse with the periciliary target membrane for further delivery of their cargo into the ciliary compartment by the intraflagellar transport (IFT). Here we describe a modified preembedding labeling method as an alternative technique to conventional postembedding methods eligible for analyses of ciliary cargo vesicles and the distribution of ciliary molecules in subciliary compartments for immunoelectron microscopy. The preembedding labeling method preserves the antigenicity of ciliary antigens and its application reveals differential localization of individual IFT proteins in vertebrate photoreceptor cilia. Since membrane vesicles are conserved, the preembedding protocol additionally allows the identification of ciliary cargo vesicles by immunolabeling of individual IFT proteins and ciliary targeting molecules in ciliary photoreceptor cells. These results do not only confirm the central function of IFT molecules in ciliary transport, but further strengthen their role in transport processes in the cytoplasm. Furthermore, evidence for different alternative transport routes of cargo vesicles directed to different target membranes is gathered.
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Affiliation(s)
- Tina Sedmak
- Department of Cell and Matrix Biology, Institute of Zoology, Johannes Gutenberg University, Mainz D-55099, Germany
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Gauthier-Fisher A, Lin DC, Greeve M, Kaplan DR, Rottapel R, Miller FD. Lfc and Tctex-1 regulate the genesis of neurons from cortical precursor cells. Nat Neurosci 2009; 12:735-44. [DOI: 10.1038/nn.2339] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2009] [Accepted: 03/31/2009] [Indexed: 12/20/2022]
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Diefenbach RJ, Miranda-Saksena M, Douglas MW, Cunningham AL. Transport and egress of herpes simplex virus in neurons. Rev Med Virol 2008; 18:35-51. [PMID: 17992661 DOI: 10.1002/rmv.560] [Citation(s) in RCA: 145] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The mechanisms of axonal transport of the alphaherpesviruses, HSV and pseudorabies virus (PrV), in neuronal axons are of fundamental interest, particularly in comparison with other viruses, and offer potential sites for antiviral intervention or development of gene therapy vectors. These herpesviruses are transported rapidly along microtubules (MTs) in the retrograde direction from the axon terminus to the dorsal root ganglion and then anterogradely in the opposite direction. Retrograde transport follows fusion and deenvelopment of the viral capsid at the axonal membrane followed by loss of most of the tegument proteins and then binding of the capsid via one or more viral proteins (VPs) to the retrograde molecular motor dynein. The HSV capsid protein pUL35 has been shown to bind to the dynein light chain Tctex1 but is likely to be accompanied by additional dynein binding of an inner tegument protein. The mechanism of anterograde transport is much more controversial with different processes being claimed for PrV and HSV: separate transport of HSV capsid/tegument and glycoproteins versus PrV transport as an enveloped virion. The controversy has not been resolved despite application, in several laboratories, of confocal microscopy (CFM), real-time fluorescence with viruses dual labelled on capsid and glycoprotein, electron microscopy in situ and immuno-electron microscopy. Different processes for each virus seem counterintuitive although they are the most divergent in the alphaherpesvirus subfamily. Current hypotheses suggest that unenveloped HSV capsids complete assembly in the axonal growth cones and varicosities, whereas with PrV unenveloped capsids are only found travelling in a retrograde direction.
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Affiliation(s)
- Russell J Diefenbach
- Centre for Virus Research, Westmead Millennium Institute, Westmead Hospital and the University of Sydney, Westmead, NSW 2145, Australia
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Lo KWH, Kogoy JM, Rasoul BA, King SM, Pfister KK. Interaction of the DYNLT (TCTEX1/RP3) light chains and the intermediate chains reveals novel intersubunit regulation during assembly of the dynein complex. J Biol Chem 2007; 282:36871-8. [PMID: 17965411 DOI: 10.1074/jbc.m705991200] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The cytoplasmic dynein 1 cargo binding domain is formed by five subunits including the intermediate chain and the DYNLT, DYNLL, and DYNLRB light chain families. Six isoforms of the intermediate chain and two isoforms of each of the light chain families have been identified in mammals. There is evidence that different subunit isoforms are involved in regulating dynein function, in particular linking dynein to different cargoes. However, it is unclear how the subunit isoforms are assembled or if there is any specificity to their interactions. Co-immunoprecipitation using DYNLT-specific antibodies reveals that dynein complexes with DYNLT light chains also contain the DYNLL and DYNLRB light chains. The DYNLT light chains, but not DYNLL light chains, associate exclusively with the dynein complex. Yeast two-hybrid and co-immunoprecipitation assays demonstrate that both members of the DYNLT family are capable of forming homodimers and heterodimers. In addition, both homodimers of the DYNLT family bind all six intermediate chain isoforms. However, DYNLT heterodimers do not bind to the intermediate chain. Thus, whereas all combinations of DYNLT light chain dimers can be made, not all of the possible combinations of the isoforms are utilized during the assembly of the dynein complex.
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Affiliation(s)
- Kevin W-H Lo
- Department of Cell Biology, School of Medicine, University of Virginia, Charlottesville, Virginia 22908, USA
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16
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Sachdev P, Menon S, Kastner DB, Chuang JZ, Yeh TY, Conde C, Caceres A, Sung CH, Sakmar TP. G protein beta gamma subunit interaction with the dynein light-chain component Tctex-1 regulates neurite outgrowth. EMBO J 2007; 26:2621-32. [PMID: 17491591 PMCID: PMC1888676 DOI: 10.1038/sj.emboj.7601716] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2006] [Accepted: 04/12/2007] [Indexed: 11/08/2022] Open
Abstract
Tctex-1, a light-chain component of the cytoplasmic dynein motor complex, can function independently of dynein to regulate multiple steps in neuronal development. However, how dynein-associated and dynein-free pools of Tctex-1 are maintained in the cell is not known. Tctex-1 was recently identified as a Gbetagamma-binding protein and shown to be identical to the receptor-independent activator of G protein signaling AGS2. We propose a novel role for the interaction of Gbetagamma with Tctex-1 in neurite outgrowth. Ectopic expression of either Tctex-1 or Gbetagamma promotes neurite outgrowth whereas interfering with their function inhibits neuritogenesis. Using embryonic mouse brain extracts, we demonstrate an endogenous Gbetagamma-Tctex-1 complex and show that Gbetagamma co-segregates with dynein-free fractions of Tctex-1. Furthermore, Gbeta competes with the dynein intermediate chain for binding to Tctex-1, regulating assembly of Tctex-1 into the dynein motor complex. We propose that Tctex-1 is a novel effector of Gbetagamma, and that Gbetagamma-Tctex-1 complex plays a key role in the dynein-independent function of Tctex-1 in regulating neurite outgrowth in primary hippocampal neurons, most likely by modulating actin and microtubule dynamics.
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Affiliation(s)
- Pallavi Sachdev
- Laboratory of Molecular Biology and Biochemistry, The Rockefeller University, New York, NY, USA
| | - Santosh Menon
- Laboratory of Molecular Biology and Biochemistry, The Rockefeller University, New York, NY, USA
| | - David B Kastner
- Laboratory of Molecular Biology and Biochemistry, The Rockefeller University, New York, NY, USA
| | - Jen-Zen Chuang
- Department of Ophthalmology, Weill Medical College of Cornell University, New York, NY, USA
| | - Ting-Yu Yeh
- Department of Ophthalmology, Weill Medical College of Cornell University, New York, NY, USA
| | | | | | - Ching-Hwa Sung
- Department of Ophthalmology, Weill Medical College of Cornell University, New York, NY, USA
- Department of Cell and Developmental Biology, Weill Medical College of Cornell University, New York, NY, USA
| | - Thomas P Sakmar
- Laboratory of Molecular Biology and Biochemistry, The Rockefeller University, New York, NY, USA
- Laboratory of Molecular Biology and Biochemistry, The Rockefeller University, 1230 York Avenue, Box 187, New York City, NY 10021, USA. Tel.: +1 212 327 8288; Fax: +1 212 327 7904; E-mail:
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17
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Lo KWH, Kogoy JM, Pfister KK. The DYNLT3 light chain directly links cytoplasmic dynein to a spindle checkpoint protein, Bub3. J Biol Chem 2007; 282:11205-12. [PMID: 17289665 DOI: 10.1074/jbc.m611279200] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cytoplasmic dynein is the motor protein responsible for the intracellular transport of various organelles and other cargoes toward microtubule minus ends. However, it remains to be determined how dynein is regulated to accomplish its varied roles. The dynein complex contains six subunits, including three classes of light chains. The two isoforms of the DYNLT (Tctex1) family of light chains, DYNLT1 and DYNLT3, have been proposed to link dynein to specific cargoes. However, no specific binding partner had been found for the DYNLT3 light chain. We find that DYNLT3 binds to Bub3, a spindle checkpoint protein. Bub3 binds exclusively to DYNLT3 and not to the other dynein light chains. Glutathione S-transferase pull-down and co-immunoprecipitation assays demonstrate that Bub3 interacts with the cytoplasmic dynein complex. DYNLT3 is present on kinetochores at prometaphase, but not later mitotic stages, demonstrating that this dynein light chain, like Bub3 and other checkpoint proteins, is depleted from the kinetochore during chromosome alignment. Knockdown of DYNLT3 with small interference RNA increases the mitotic index, in particular, the number of cells in prophase/prometaphase. These results demonstrate that dynein binds directly to a component of the spindle checkpoint complex through the DYNLT3 light chain. Thus, DYNLT3 contributes to dynein cargo binding specificity. These data also suggest that the subpopulation of dynein, containing the DYNLT3 light chain, may be important for chromosome congression, in addition to having a role in the transport of checkpoint proteins from the kinetochore to the spindle pole.
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Affiliation(s)
- Kevin W-H Lo
- Department of Cell Biology, School of Medicine, University of Virginia, Charlottesville, Virginia 22908-0732, USA
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18
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Cheng HH, Liu SH, Lee HC, Lin YS, Huang ZH, Hsu CI, Chen YC, Chang YC. Heavy chain of cytoplasmic dynein is a major component of the postsynaptic density fraction. J Neurosci Res 2006; 84:244-54. [PMID: 16721762 DOI: 10.1002/jnr.20898] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A protein with an apparent molecular size of 490 kDa was found in the postsynaptic density (PSD) fraction isolated from porcine cerebral cortices and rat forebrains, and this 490 kDa protein accounted for approximately 3% of the total protein of these samples. Matrix-assisted laser desorption ionization-time of flight mass spectrometric and Western blotting analyses consistently indicated that this 490 kDa protein consisted primarily of the heavy chain of cytoplasmic dynein (cDHC). Immunocytochemical analyses showed that cDHC was found in 92% and 89% of the phalloidin-positive protrusions that were themselves associated with discrete clusters of synaptophysin, a presynaptic terminal marker, and PSD-95, a postsynaptic marker, on neuronal processes, respectively. Quantitative Western blotting analyses of various subcellular fractions isolated from porcine cerebral cortices and rat forebrains further showed that not only the heavy but also the intermediate chains of dynein are enriched in the PSD fraction. Cytoplasmic dynein is a microtubule-associated motor protein complex that drives the movement of various cargos toward the minus ends of microtubules and plays many other diverse functions in the cell. Our results that cDHC is a major component of the PSD fraction, that both dynein heavy and intermediate chains are enriched in the PSD fraction and that cDHC is present in dendritic spines raise the possibilities that cytoplasmic dynein may play structural and functional roles in the postsynaptic terminal.
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Affiliation(s)
- Huei-Hsuan Cheng
- Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan, Republic of China
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19
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Dedesma C, Chuang JZ, Alfinito PD, Sung CH. Dynein light chain Tctex-1 identifies neural progenitors in adult brain. J Comp Neurol 2006; 496:773-86. [PMID: 16628620 DOI: 10.1002/cne.20958] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The identity and biology of stem cells and progenitors in the adult brain are of considerable interest, because these cells hold great promise for the development of novel therapies for damaged brain tissue in human diseases. This research field critically needs biological markers that specifically identify the resident precursors in the germinal zones of the adult central nervous system so that the discovery of regulatory influences for adult neurogenesis may be facilitated. In this study, by using a combination of in situ hybridization, bromodeoxyuridine incorporation, immunocolocalization, and ultrastructural studies, we show that in rodents Tctex-1, a cytoplasmic dynein light chain, is selectively enriched in almost all cycling progenitors and young neuronal progeny, but not in mature granular cells and astrocytes, in the subgranular zone of the adult dentate gyrus. Tctex-1 is also selectively abundant in cells closely resembling previously described immature progenitors and migrating neuroblasts at the subventricular zone of the lateral ventricle. Our results suggest that Tctex-1 serves as a novel marker for the identification of neural progenitors of the adult brain.
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Affiliation(s)
- Carlos Dedesma
- Graduate Program in Neuroscience, Weill Medical College of Cornell University, New York, NY 10021, USA
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20
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Lo KWH, Kan HM, Pfister KK. Identification of a Novel Region of the Cytoplasmic Dynein Intermediate Chain Important for Dimerization in the Absence of the Light Chains. J Biol Chem 2006; 281:9552-9. [PMID: 16452477 DOI: 10.1074/jbc.m511721200] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cytoplasmic dynein is the multisubunit protein complex responsible for many microtubule-based intracellular movements. Its cargo binding domain consists of dimers of five subunits: the intermediate chains, the light intermediate chains, and the Tctex1, Roadblock, and LC8 light chains. The intermediate chains have a key role in the dynein complex. They bind the three light chains and the heavy chains, which contain the motor domains, but little is known about how the two intermediate chains interact. There are six intermediate chain isoforms, and it has been hypothesized that different isoforms may regulate specific dynein functions. However, there are little data on the potential combinations of the intermediate chain isoforms in the dynein complexes. We used co-immunoprecipitation analyses to demonstrate that all combinations of homo- and heterodimers of the six intermediate chains are possible. Therefore the formation of dynein complexes with different combinations of isoforms is not limited by interaction between the various intermediate chains. We further sought to identify the domain necessary for the dimerization of the intermediate chains. Analysis of a series of truncation and deletion mutants showed that a 61-amino-acid region is necessary for dimerization of the intermediate chain. This region does not include the N-terminal coiled-coil, the C-terminal WD repeat domain, or the three different binding sites for the Tctex1, LC8, and Roadblock light chains. Analytical gel filtration and covalent cross-linking of purified recombinant polypeptides further demonstrated that the intermediate chains can dimerize in vitro in the absence of the light chains.
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Affiliation(s)
- Kevin W-H Lo
- Department of Cell Biology, University of Virginia, Charlottesville, Virginia 22908, USA
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21
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JiméNez-Mateos E, Wandosell F, Reiner O, Avila J, González-Billault C. Binding of microtubule-associated protein 1B to LIS1 affects the interaction between dynein and LIS1. Biochem J 2005; 389:333-41. [PMID: 15762842 PMCID: PMC1175110 DOI: 10.1042/bj20050244] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
For neuronal migration to occur, the cell must undergo morphological changes that require modifications of the cytoskeleton. Several different MAPs (microtubule-associated proteins) or actin-binding proteins are proposed to be involved in the migration of neurons. Therefore we have specifically analysed how two members of the MAP family, MAP1B and LIS1 (lissencephaly-related protein 1), interact with one another and participate in neuronal migration. Our results indicate that, in hippocampal neurons, MAP1B and LIS1 co-localize, associate and interact with each another. The interaction between these two MAPs is regulated by the phosphorylation of MAP1B. Furthermore, this interaction interferes with the association between LIS1 and the microtubule-dependent molecular motor, dynein. Clearly, the differential binding of these cytoskeletal proteins could regulate the functions attributed to the LIS1-dynein complex, including those related to extension of the neural processes necessary for neuronal migration.
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Affiliation(s)
- Eva M. JiméNez-Mateos
- *Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Campus de Cantoblanco, Cantoblanco 28049, Madrid, Spain
| | - Francisco Wandosell
- *Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Campus de Cantoblanco, Cantoblanco 28049, Madrid, Spain
| | - Orly Reiner
- †Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot, Israel
| | - Jesús Avila
- *Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Campus de Cantoblanco, Cantoblanco 28049, Madrid, Spain
- Correspondence may be addressed to either of the authors (email or )
| | - Christian González-Billault
- *Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Campus de Cantoblanco, Cantoblanco 28049, Madrid, Spain
- Correspondence may be addressed to either of the authors (email or )
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22
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Yeh TY, Chuang JZ, Sung CH. Dynein light chain rp3 acts as a nuclear matrix-associated transcriptional modulator in a dynein-independent pathway. J Cell Sci 2005; 118:3431-43. [PMID: 16079286 DOI: 10.1242/jcs.02472] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Cytoplasmic dynein is a motor protein complex involved in microtubule-based cargo movement. Previous biochemical evidence suggests that dynein light chain subunits also exist outside the dynein complex. Here we show that the dynein light chain rp3 is present in both the cytoplasm and the nucleus. Nuclear rp3 binds to and assembles with the transcription factor SATB1 at nuclear matrix-associated structures. Dynein intermediate chain was also detected in the nucleus, but it was dispensable for the rp3-SATB1 interaction. SATB1 facilitates the nuclear localization of rp3, whereas rp3 and dynein motor activity are not essential for nuclear accumulation of SATB1. The nuclear rp3-SATB1 protein complex is assembled with a DNA element of the matrix attachment region of the Bcl2 gene. Finally, rp3 is involved in SATB1-mediated gene repression of Bcl2. Our data provide evidence that dynein subunit rp3 has functions independent of the dynein motor.
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Affiliation(s)
- Ting-Yu Yeh
- Department of Ophthalmology, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY 10021, USA
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23
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Chuang JZ, Yeh TY, Bollati F, Conde C, Canavosio F, Caceres A, Sung CH. The dynein light chain Tctex-1 has a dynein-independent role in actin remodeling during neurite outgrowth. Dev Cell 2005; 9:75-86. [PMID: 15992542 PMCID: PMC3857739 DOI: 10.1016/j.devcel.2005.04.003] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2004] [Revised: 01/19/2005] [Accepted: 04/13/2005] [Indexed: 01/19/2023]
Abstract
Coordinated microtubule and microfilament changes are essential for the morphological development of neurons; however, little is know about the underlying molecular machinery linking these two cytoskeletal systems. Similarly, the indispensable role of RhoGTPase family proteins has been demonstrated, but it is unknown how their activities are specifically regulated in different neurites. In this paper, we show that the cytoplasmic dynein light chain Tctex-1 plays a key role in multiple steps of hippocampal neuron development, including initial neurite sprouting, axon specification, and later dendritic elaboration. The neuritogenic effects elicited by Tctex-1 are independent from its cargo adaptor role for dynein motor transport. Finally, our data suggest that the selective high level of Tctex-1 at the growth cone of growing axons drives fast neurite extension by modulating actin dynamics and also Rac1 activity.
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Affiliation(s)
- Jen-Zen Chuang
- Department of Ophthalmology, Weill Medical College of Cornell University, 1300 York Avenue, New York, New York 10012
| | - Ting-Yu Yeh
- Department of Ophthalmology, Weill Medical College of Cornell University, 1300 York Avenue, New York, New York 10012
| | - Flavia Bollati
- INIMEC-CONICET, Avenue Friuli 2434, 5016 Cordoba, Argentina
| | - Cecilia Conde
- INIMEC-CONICET, Avenue Friuli 2434, 5016 Cordoba, Argentina
| | | | | | - Ching-Hwa Sung
- Department of Cell and Development Biology, Weill Medical College of Cornell University, 1300 York Avenue, New York, New York 10012
- Correspondence:
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24
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Mueller S, Wimmer E, Cello J. Poliovirus and poliomyelitis: a tale of guts, brains, and an accidental event. Virus Res 2005; 111:175-93. [PMID: 15885840 DOI: 10.1016/j.virusres.2005.04.008] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Nearly 100 years after its discovery poliovirus remains one of most thoroughly studied and best understood virus models for the molecular virologist. While poliovirus has been of vital importance for our insight into picornavirus biology at the cellular and biochemical level, it is ironic to note that, due to the early success in defeating poliomyelitis in the developed world through vaccination, many of the basic aspects of poliovirus pathogenesis remain poorly understood. This is chiefly due to the lack of an adequate and affordable animal model, save of old world monkeys. Fundamental questions, such as the identity of the target cells during the enteric phase of infection, or mechanisms of systemic spread are still unanswered. This review will attempt to summarize our current knowledge of the molecular biology of poliovirus, its pathogenesis, as well as recent advances in the areas of cell and tissue tropism and mechanisms of central nervous system invasion.
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Affiliation(s)
- Steffen Mueller
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY 11794, USA
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25
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Abstract
TcTex-1, one of three dynein light chains of the dynein motor complex, has been implicated in targeting and binding cargoes to cytoplasmic dynein for retrograde or apical transport. Interactions between TcTex-1 and a diverse set of proteins such as the dynein intermediate chain, Fyn, DOC2, FIP1, the poliovirus receptor, CD155, and the rhodopsin cytoplasmic tail have been reported; yet, despite the broad range of targets, a consensus binding sequence remains uncertain. Consequently, we have solved the crystal structure of the full-length Drosophila homolog of TcTex-1 to 1.7 A resolution using MAD phasing to gain insight into its function and target specificity. The structure is homodimeric with a domain swapping of beta-strand 2 and has a fold similar to the dynein light chain, LC8. Based on structural alignment, the TcTex-1 and LC8 sequences show no identity, although the root mean square deviation between secondary structural elements is less than 1.6 A. Moreover, the N terminus, which is equivalent to beta-strand 1 in LC8, is splayed out and binds to a crystallographic dimer as an anti-parallel beta-strand at the same position as the neuronal nitric-oxide synthase peptide in the LC8 complex. Similarity to LC8 and comparison to the LC8-neuronal nitricoxide synthase complex suggest that TcTex-1 binds its targets in a similar manner as LC8 and provides insight to the lack of strict sequence identity among the targets for TcTex-1.
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Affiliation(s)
- John C Williams
- Department of Biochemistry and Molecular Biophysics, Howard Hughes Medical Institute, Columbia University, New York, NY 10032, USA
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26
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Lai M, Wang F, Rohan JG, Maeno-Hikichi Y, Chen Y, Zhou Y, Gao G, Sather WA, Zhang JF. A tctex1-Ca2+ channel complex for selective surface expression of Ca2+ channels in neurons. Nat Neurosci 2005; 8:435-42. [PMID: 15768038 DOI: 10.1038/nn1418] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2004] [Accepted: 02/08/2005] [Indexed: 11/09/2022]
Abstract
Voltage-gated Ca(2+) channels (VGCCs) are important in regulating a variety of cellular functions in neurons. It remains poorly understood how VGCCs with different functions are sorted within neurons. Here we show that the t-complex testis-expressed 1 (tctex1) protein, a light-chain subunit of the dynein motor complex, interacts directly and selectively with N- and P/Q-type Ca(2+) channels, but not L-type Ca(2+) channels. The interaction is insensitive to Ca(2+). Overexpression in hippocampal neurons of a channel fragment containing the binding domain for tctex1 significantly decreases the surface expression of endogenous N- and P/Q-type Ca(2+) channels but not L-type Ca(2+) channels, as determined by immunostaining. Furthermore, disruption of the tctex1-Ca(2+) channel interaction significantly reduces the Ca(2+) current density in hippocampal neurons. These results underscore the importance of the specific tctex1-channel interaction in determining sorting and trafficking of neuronal Ca(2+) channels with different functionalities.
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Affiliation(s)
- Meizan Lai
- Department of Pharmacology, University of Pennsylvania School of Medicine, 3620 Hamilton Walk, Philadelphia, Pennsylvania 19104, USA
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27
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Douglas MW, Diefenbach RJ, Homa FL, Miranda-Saksena M, Rixon FJ, Vittone V, Byth K, Cunningham AL. Herpes simplex virus type 1 capsid protein VP26 interacts with dynein light chains RP3 and Tctex1 and plays a role in retrograde cellular transport. J Biol Chem 2004; 279:28522-30. [PMID: 15117959 DOI: 10.1074/jbc.m311671200] [Citation(s) in RCA: 130] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cytoplasmic dynein is the major molecular motor involved in minus-end-directed cellular transport along microtubules. There is increasing evidence that the retrograde transport of herpes simplex virus type 1 along sensory axons is mediated by cytoplasmic dynein, but the viral and cellular proteins involved are not known. Here we report that the herpes simplex virus outer capsid protein VP26 interacts with dynein light chains RP3 and Tctex1 and is sufficient to mediate retrograde transport of viral capsids in a cellular model. A library of herpes simplex virus capsid and tegument structural genes was constructed and tested for interactions with dynein subunits in a yeast two-hybrid system. A strong interaction was detected between VP26 and the homologous 14-kDa dynein light chains RP3 and Tctex1. In vitro pull-down assays confirmed binding of VP26 to RP3, Tctex1, and intact cytoplasmic dynein complexes. Recombinant herpes simplex virus capsids were constructed either with or without VP26. In pull-down assays VP26+ capsids bound to RP3; VP26-capsids did not. To investigate intracellular transport, the recombinant viral capsids were microinjected into living cells and incubated at 37 degrees C. After 1 h VP26+ capsids were observed to co-localize with RP3, Tctex1, and microtubules. After 2 or 4 h VP26+ capsids had moved closer to the cell nucleus, whereas VP26-capsids remained in a random distribution. We propose that VP26 mediates binding of incoming herpes simplex virus capsids to cytoplasmic dynein during cellular infection, through interactions with dynein light chains.
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Affiliation(s)
- Mark W Douglas
- Centre for Virus Research, Westmead Millennium Institute, University of Sydney and Westmead Hospital, Westmead 2145, New South Wales, Australia
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28
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Abstract
Accumulating evidence has indicated that neurotrophin receptor trafficking plays an important role in neurotrophin-mediated signaling in developing as well as mature neurons. However, little is known about the molecular mechanisms and the components of neurotrophin receptor vesicular transport. This article will describe how neurotrophin receptors, Trk and p75 neurotrophin receptor (p75NTR), are intimately involved in the axonal transport process. In particular, the molecules that may direct Trk receptor trafficking in the axon will be discussed. Finally, potential mechanisms by which receptor-containing vesicles link to molecular cytoskeletal motors will be presented.
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Affiliation(s)
- Hiroko Yano
- Molecular Neurobiology Program, Skirball Institute of Biomolecular Medicine, Departments of Cell Biology, Physiology and Neuroscience, New York University School of Medicine, 540 First Avenue, New York, New York 10016, USA.
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29
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Boylan KLM, Hays TS. The gene for the intermediate chain subunit of cytoplasmic dynein is essential in Drosophila. Genetics 2002; 162:1211-20. [PMID: 12454067 PMCID: PMC1462348 DOI: 10.1093/genetics/162.3.1211] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The microtubule motor cytoplasmic dynein powers a variety of intracellular transport events that are essential for cellular and developmental processes. A current hypothesis is that the accessory subunits of the dynein complex are important for the specialization of cytoplasmic dynein function. In a genetic approach to understanding the range of dynein functions and the contribution of the different subunits to dynein motor function and regulation, we have identified mutations in the gene for the cytoplasmic dynein intermediate chain, Dic19C. We used a functional Dic transgene in a genetic screen to recover X-linked lethal mutations that require this transgene for viability. Three Dic mutations were identified and characterized. All three Dic alleles result in larval lethality, demonstrating that the intermediate chain serves an essential function in Drosophila. Like a deficiency that removes Dic19C, the Dic mutations dominantly enhance the rough eye phenotype of Glued(1), a dominant mutation in the gene for the p150 subunit of the dynactin complex, a dynein activator. Additionally, we used complementation analysis to identify an existing mutation, shortwing (sw), as an allele of the dynein intermediate chain gene. Unlike the Dic alleles isolated de novo, shortwing is homozygous viable and exhibits recessive and temperature-sensitive defects in eye and wing development. These phenotypes are rescued by the wild-type Dic transgene, indicating that shortwing is a viable allele of the dynein intermediate chain gene and revealing a novel role for dynein function during wing development.
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Affiliation(s)
- Kristin L M Boylan
- University of Minnesota, Department of Genetics, Cell Biology and Development, Minneapolis 55455, USA
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30
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Mueller S, Cao X, Welker R, Wimmer E. Interaction of the poliovirus receptor CD155 with the dynein light chain Tctex-1 and its implication for poliovirus pathogenesis. J Biol Chem 2002; 277:7897-904. [PMID: 11751937 DOI: 10.1074/jbc.m111937200] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The cellular receptor for poliovirus CD155 (or PVR) is the founding member of a new class of membrane-associated immunoglobulin-like proteins, which include the mouse tumor-associated antigen E4 (Tage4) and three proteins termed "nectins." Using a yeast two-hybrid screen we have discovered that the cytoplasmic domain of CD155 associates strongly and specifically with Tctex-1, a light chain of the dynein motor complex, the latter representing the major driving force for retrograde transport of endocytic vesicles and membranous organelles. We confirmed the interaction biochemically and by co-immunoprecipitation, and we mapped the Tctex-1 binding site to a SKCSR motif within the juxtamembrane region of CD155. Tctex-1 immunoreactivity was detected in mouse sciatic nerve and spinal cord (two tissues of central importance for poliovirus pathogenesis) in punctate, possibly vesicular, patterns. We propose that the cytoplasmic domain may target CD155-containing endocytic vesicles to the microtubular network. Neurotropic viruses like poliovirus, herpesvirus, rabies virus, and pseudorabies virus all utilize neuronal retrograde transport to invade the central nervous system. Association with Tctex-1 and, hence, with the dynein motor complex may offer an explanation for how poliovirus hijacks the cellular transport machinery to retrogradely ascend along the axon to the neuronal cell body.
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Affiliation(s)
- Steffen Mueller
- Department of Molecular Genetics and Microbiology, State University of New York, Stony Brook, New York 11794, USA
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