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Langley A, Abeling-Wang S, Wagner E, Salogiannis J. Movement of the endoplasmic reticulum is driven by multiple classes of vesicles marked by Rab-GTPases. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.14.592021. [PMID: 38798686 PMCID: PMC11118391 DOI: 10.1101/2024.05.14.592021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Peripheral endoplasmic reticulum (ER) tubules move along microtubules to interact with various organelles through membrane contact sites (MCS). Traditionally, ER moves by either sliding along stable microtubules via molecular motors or attaching to the plus ends of dynamic microtubules through tip attachment complexes (TAC). A recently discovered third process, hitchhiking, involves motile vesicles pulling ER tubules along microtubules. Previous research showed that ER hitchhikes on Rab5- and Rab7-marked endosomes, but it is uncertain if other Rab-vesicles can do the same. In U2OS cells, we screened Rabs for their ability to cotransport with ER tubules and found that ER hitchhikes on post-Golgi vesicles marked by Rab6 (isoforms a and b). Rab6-ER hitchhiking occurs independently of ER-endolysosome contacts and TAC-mediated ER movement. Disrupting either Rab6 or the motility of Rab6-vesicles reduces overall ER movement. Conversely, relocating these vesicles to the cell periphery causes peripheral ER accumulation, indicating that Rab6-vesicle motility is crucial for a subset of ER movements. Proximal post-Golgi vesicles marked by TGN46 are involved in Rab6-ER hitchhiking, while other post-Golgi vesicles (Rabs 8/10/11/13/14) are not essential for ER movement. Our further analysis finds that ER to Golgi vesicles marked by Rab1 are also capable of driving a subset of ER movements. Taken together, our findings suggest that ER hitchhiking on Rab-vesicles is a significant mode of ER movement. SIGNIFICANCE STATEMENT Peripheral endoplasmic reticulum tubules move on microtubules by either attaching to motors (cargo adaptor-mediated), dynamic microtubule-plus ends (tip attachment complexes) or motile vesicles (hitchhiking) but the prevalence of each mode is not clearPost-Golgi vesicles marked by Rab6/TGN46 and ER to Golgi vesicles marked by Rab1 drive ER movementsER hitchhiking on multiple classes of vesicles (endolysosomal, post-Golgi and ER to Golgi) marked by Rabs plays a prominent role in ER movement.
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2
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Saffari A, Brechmann B, Böger C, Saber WA, Jumo H, Whye D, Wood D, Wahlster L, Alecu JE, Ziegler M, Scheffold M, Winden K, Hubbs J, Buttermore ED, Barrett L, Borner GHH, Davies AK, Ebrahimi-Fakhari D, Sahin M. High-content screening identifies a small molecule that restores AP-4-dependent protein trafficking in neuronal models of AP-4-associated hereditary spastic paraplegia. Nat Commun 2024; 15:584. [PMID: 38233389 PMCID: PMC10794252 DOI: 10.1038/s41467-023-44264-1] [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: 06/07/2023] [Accepted: 12/06/2023] [Indexed: 01/19/2024] Open
Abstract
Unbiased phenotypic screens in patient-relevant disease models offer the potential to detect therapeutic targets for rare diseases. In this study, we developed a high-throughput screening assay to identify molecules that correct aberrant protein trafficking in adapter protein complex 4 (AP-4) deficiency, a rare but prototypical form of childhood-onset hereditary spastic paraplegia characterized by mislocalization of the autophagy protein ATG9A. Using high-content microscopy and an automated image analysis pipeline, we screened a diversity library of 28,864 small molecules and identified a lead compound, BCH-HSP-C01, that restored ATG9A pathology in multiple disease models, including patient-derived fibroblasts and induced pluripotent stem cell-derived neurons. We used multiparametric orthogonal strategies and integrated transcriptomic and proteomic approaches to delineate potential mechanisms of action of BCH-HSP-C01. Our results define molecular regulators of intracellular ATG9A trafficking and characterize a lead compound for the treatment of AP-4 deficiency, providing important proof-of-concept data for future studies.
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Affiliation(s)
- Afshin Saffari
- Department of Neurology & F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
- Division of Child Neurology and Inherited Metabolic Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Barbara Brechmann
- Department of Neurology & F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Cedric Böger
- Department of Neurology & F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Wardiya Afshar Saber
- Department of Neurology & F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Hellen Jumo
- Department of Neurology & F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
- Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Dosh Whye
- Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Delaney Wood
- Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Lara Wahlster
- Department of Hematology & Oncology, Boston Children's Hospital & Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, 02115, USA
| | - Julian E Alecu
- Department of Neurology & F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Marvin Ziegler
- Department of Neurology & F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Marlene Scheffold
- Department of Neurology & F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Kellen Winden
- Department of Neurology & F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Jed Hubbs
- Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Elizabeth D Buttermore
- Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Lee Barrett
- Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Georg H H Borner
- Department of Proteomics and Signal Transduction, Max-Planck-Institute of Biochemistry, Martinsried, 82152, Germany
| | - Alexandra K Davies
- Department of Proteomics and Signal Transduction, Max-Planck-Institute of Biochemistry, Martinsried, 82152, Germany
- School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, M13 9PT, UK
| | - Darius Ebrahimi-Fakhari
- Department of Neurology & F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA.
- Movement Disorders Program, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA.
| | - Mustafa Sahin
- Department of Neurology & F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
- Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
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3
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López-Alcalá J, Gordon A, Trávez A, Tercero-Alcázar C, Correa-Sáez A, González-Rellán MJ, Rangel-Zúñiga OA, Rodríguez A, Membrives A, Frühbeck G, Nogueiras R, Calzado MA, Guzmán-Ruiz R, Malagón MM. Localization, traffic and function of Rab34 in adipocyte lipid and endocrine functions. J Biomed Sci 2024; 31:2. [PMID: 38183057 PMCID: PMC10770960 DOI: 10.1186/s12929-023-00990-8] [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: 03/21/2023] [Accepted: 12/20/2023] [Indexed: 01/07/2024] Open
Abstract
BACKGROUND Excessive lipid accumulation in the adipose tissue in obesity alters the endocrine and energy storage functions of adipocytes. Adipocyte lipid droplets represent key organelles coordinating lipid storage and mobilization in these cells. Recently, we identified the small GTPase, Rab34, in the lipid droplet proteome of adipocytes. Herein, we have characterized the distribution, intracellular transport, and potential contribution of this GTPase to adipocyte physiology and its regulation in obesity. METHODS 3T3-L1 and human primary preadipocytes were differentiated in vitro and Rab34 distribution and trafficking were analyzed using markers of cellular compartments. 3T3-L1 adipocytes were transfected with expression vectors and/or Rab34 siRNA and assessed for secretory activity, lipid accumulation and expression of proteins regulating lipid metabolism. Proteomic and protein interaction analyses were employed for the identification of the Rab34 interactome. These studies were combined with functional analysis to unveil the role played by the GTPase in adipocytes, with a focus on the actions conveyed by Rab34 interacting proteins. Finally, Rab34 regulation in response to obesity was also evaluated. RESULTS Our results show that Rab34 localizes at the Golgi apparatus in preadipocytes. During lipid droplet biogenesis, Rab34 translocates from the Golgi to endoplasmic reticulum-related compartments and then reaches the surface of adipocyte lipid droplets. Rab34 exerts distinct functions related to its intracellular location. Thus, at the Golgi, Rab34 regulates cisternae integrity as well as adiponectin trafficking and oligomerization. At the lipid droplets, this GTPase controls lipid accumulation and lipolysis through its interaction with the E1-ubiquitin ligase, UBA1, which induces the ubiquitination and proteasomal degradation of the fatty acid transporter and member of Rab34 interactome, FABP5. Finally, Rab34 levels in the adipose tissue and adipocytes are regulated in response to obesity and related pathogenic insults (i.e., fibrosis). CONCLUSIONS Rab34 plays relevant roles during adipocyte differentiation, including from the regulation of the oligomerization (i.e., biological activity) and secretion of a major adipokine with insulin-sensitizing actions, adiponectin, to lipid storage and mobilization from lipid droplets. Rab34 dysregulation in obesity may contribute to the altered adipokine secretion and lipid metabolism that characterize adipocyte dysfunction in conditions of excess adiposity.
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Affiliation(s)
- Jaime López-Alcalá
- Department of Cell Biology, Physiology, and Immunology, Maimonides Institute for Biomedical Research of Córdoba (IMIBIC), University of Córdoba (UCO), Reina Sofía University Hospital (HURS), Córdoba, Spain
| | - Ana Gordon
- Department of Cell Biology, Physiology, and Immunology, Maimonides Institute for Biomedical Research of Córdoba (IMIBIC), University of Córdoba (UCO), Reina Sofía University Hospital (HURS), Córdoba, Spain.
| | - Andrés Trávez
- Department of Cell Biology, Physiology, and Immunology, Maimonides Institute for Biomedical Research of Córdoba (IMIBIC), University of Córdoba (UCO), Reina Sofía University Hospital (HURS), Córdoba, Spain
| | - Carmen Tercero-Alcázar
- Department of Cell Biology, Physiology, and Immunology, Maimonides Institute for Biomedical Research of Córdoba (IMIBIC), University of Córdoba (UCO), Reina Sofía University Hospital (HURS), Córdoba, Spain
| | - Alejandro Correa-Sáez
- Department of Cell Biology, Physiology, and Immunology, Maimonides Institute for Biomedical Research of Córdoba (IMIBIC), University of Córdoba (UCO), Reina Sofía University Hospital (HURS), Córdoba, Spain
| | - María Jesús González-Rellán
- CIBER Physiopathology of Obesity and Nutrition (CIBERobn), ISCIII, Madrid, Spain
- Department of Physiology, CiMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, Spain
| | - Oriol A Rangel-Zúñiga
- CIBER Physiopathology of Obesity and Nutrition (CIBERobn), ISCIII, Madrid, Spain
- Lipids and Atherosclerosis Unit, IMIBIC/University of Córdoba (UCO), Reina Sofía University Hospital (HURS), Córdoba, Spain
| | - Amaia Rodríguez
- CIBER Physiopathology of Obesity and Nutrition (CIBERobn), ISCIII, Madrid, Spain
- Metabolic Research Laboratory, Department of Endocrinology & Nutrition, Clinic, University of Navarra, IdiSNA, Pamplona, Spain
| | - Antonio Membrives
- Department of Medical-Surgical Specialties, University of Córdoba (UCO), Reina Sofia University Hospital (HURS), Córdoba, Spain
| | - Gema Frühbeck
- CIBER Physiopathology of Obesity and Nutrition (CIBERobn), ISCIII, Madrid, Spain
- Metabolic Research Laboratory, Department of Endocrinology & Nutrition, Clinic, University of Navarra, IdiSNA, Pamplona, Spain
| | - Rubén Nogueiras
- CIBER Physiopathology of Obesity and Nutrition (CIBERobn), ISCIII, Madrid, Spain
- Department of Physiology, CiMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, Spain
| | - Marco A Calzado
- Department of Cell Biology, Physiology, and Immunology, Maimonides Institute for Biomedical Research of Córdoba (IMIBIC), University of Córdoba (UCO), Reina Sofía University Hospital (HURS), Córdoba, Spain
| | - Rocío Guzmán-Ruiz
- Department of Cell Biology, Physiology, and Immunology, Maimonides Institute for Biomedical Research of Córdoba (IMIBIC), University of Córdoba (UCO), Reina Sofía University Hospital (HURS), Córdoba, Spain
- CIBER Physiopathology of Obesity and Nutrition (CIBERobn), ISCIII, Madrid, Spain
| | - María M Malagón
- Department of Cell Biology, Physiology, and Immunology, Maimonides Institute for Biomedical Research of Córdoba (IMIBIC), University of Córdoba (UCO), Reina Sofía University Hospital (HURS), Córdoba, Spain.
- CIBER Physiopathology of Obesity and Nutrition (CIBERobn), ISCIII, Madrid, Spain.
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G. Dornan L, C. Simpson J. Rab6-mediated retrograde trafficking from the Golgi: the trouble with tubules. Small GTPases 2023; 14:26-44. [PMID: 37488775 PMCID: PMC10392741 DOI: 10.1080/21541248.2023.2238330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 07/13/2023] [Accepted: 07/15/2023] [Indexed: 07/26/2023] Open
Abstract
Next year marks one-quarter of a century since the discovery of the so-called COPI-independent pathway, which operates between the Golgi apparatus and the endoplasmic reticulum (ER) in eukaryotic cells. Unlike almost all other intracellular trafficking pathways, this pathway is not regulated by the physical accumulation of multisubunit proteinaceous coat molecules, but instead by the small GTPase Rab6. What also sets it apart from other pathways is that the transport carriers themselves often take the form of tubules, rather than conventional vesicles. In this review, we assess the relevant literature that has accumulated to date, in an attempt to provide a concerted description of how this pathway is regulated. We discuss the possible cargo molecules that are carried in this pathway, and the likely mechanism of Rab6 tubule biogenesis, including how the cargo itself may play a critical role. We also provide perspective surrounding the various molecular motors of the kinesin, myosin and dynein families that have been implicated in driving Rab6-coated tubular membranes long distances through the cell prior to delivering their cargo to the ER. Finally, we also raise several important questions that require resolution, if we are to ultimately provide a comprehensive molecular description of how the COPI-independent pathway is controlled.
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Affiliation(s)
- Lucy G. Dornan
- Cell Screening Laboratory, UCD School of Biology & Environmental Science, University College Dublin, Dublin, Ireland
| | - Jeremy C. Simpson
- Cell Screening Laboratory, UCD School of Biology & Environmental Science, University College Dublin, Dublin, Ireland
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5
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Lim DH, Choi MS, Jeon JW, Lee YS. MicroRNA miR-252-5p regulates the Notch signaling pathway by targeting Rab6 in Drosophila wing development. INSECT SCIENCE 2023; 30:1431-1444. [PMID: 36847222 DOI: 10.1111/1744-7917.13188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 02/06/2023] [Accepted: 02/08/2023] [Indexed: 06/18/2023]
Abstract
The Notch signaling pathway plays a central role in the development of various organisms. However, dysregulation of microRNAs (miRNAs), which are crucial regulators of gene expression, can disrupt signaling pathways at all stages of development. Although Notch signaling is involved in wing development in Drosophila, the mechanism underlying miRNA-based regulation of the Notch signaling pathway is unclear. Here, we report that loss of Drosophila miR-252 increases the size of adult wings, whereas the overexpression of miR-252 in specific compartments of larval wing discs leads to patterning defects in the adult wings. The miR-252 overexpression-induced wing phenotypes were caused by aberrant Notch signaling with intracellular accumulation of the full-length Notch receptor during development, which could be due to defects in intracellular Notch trafficking associated with its recycling to the plasma membrane and autophagy-mediated degradation. Moreover, we identified Rab6 as a direct target of miR-252-5p; Rab6 encodes a small Ras-like GTPase that regulates endosomal trafficking pathways. Consistent with this finding, RNAi-mediated downregulation of Rab6 led to similar defects in both wing patterning and Notch signaling. Notably, co-overexpression of Rab6 completely rescued the wing phenotype associated with miR-252 overexpression, further supporting that Rab6 is a biologically relevant target of miR-252-5p in the context of wing development. Thus, our data indicate that the miR-252-5p-Rab6 regulatory axis is involved in Drosophila wing development by controlling the Notch signaling pathway.
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Affiliation(s)
- Do-Hwan Lim
- School of Systems Biomedical Science, Soongsil University, Seoul, Republic of Korea
| | - Min-Seok Choi
- College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea
- Institute of Animal Molecular Biotechnology, Korea University, Seoul, Republic of Korea
| | - Ji Won Jeon
- School of Systems Biomedical Science, Soongsil University, Seoul, Republic of Korea
| | - Young Sik Lee
- College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea
- Institute of Animal Molecular Biotechnology, Korea University, Seoul, Republic of Korea
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Saffari A, Brechmann B, Boeger C, Saber WA, Jumo H, Whye D, Wood D, Wahlster L, Alecu J, Ziegler M, Scheffold M, Winden K, Hubbs J, Buttermore E, Barrett L, Borner G, Davies A, Sahin M, Ebrahimi-Fakhari D. High-Content Small Molecule Screen Identifies a Novel Compound That Restores AP-4-Dependent Protein Trafficking in Neuronal Models of AP-4-Associated Hereditary Spastic Paraplegia. RESEARCH SQUARE 2023:rs.3.rs-3036166. [PMID: 37398196 PMCID: PMC10312991 DOI: 10.21203/rs.3.rs-3036166/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Unbiased phenotypic screens in patient-relevant disease models offer the potential to detect novel therapeutic targets for rare diseases. In this study, we developed a high-throughput screening assay to identify molecules that correct aberrant protein trafficking in adaptor protein complex 4 (AP-4) deficiency, a rare but prototypical form of childhood-onset hereditary spastic paraplegia, characterized by mislocalization of the autophagy protein ATG9A. Using high-content microscopy and an automated image analysis pipeline, we screened a diversity library of 28,864 small molecules and identified a lead compound, C-01, that restored ATG9A pathology in multiple disease models, including patient-derived fibroblasts and induced pluripotent stem cell-derived neurons. We used multiparametric orthogonal strategies and integrated transcriptomic and proteomic approaches to delineate putative molecular targets of C-01 and potential mechanisms of action. Our results define molecular regulators of intracellular ATG9A trafficking and characterize a lead compound for the treatment of AP-4 deficiency, providing important proof-of-concept data for future Investigational New Drug (IND)-enabling studies.
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Affiliation(s)
| | | | | | | | | | - Dosh Whye
- Boston Children's Hospital, Harvard Medical School
| | - Delaney Wood
- Boston Children's Hospital, Harvard Medical School
| | | | - Julian Alecu
- Boston Children's Hospital, Harvard Medical School
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7
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The role of CaMKK2 in Golgi-associated vesicle trafficking. Biochem Soc Trans 2023; 51:331-342. [PMID: 36815702 PMCID: PMC9987998 DOI: 10.1042/bst20220833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 02/03/2023] [Accepted: 02/07/2023] [Indexed: 02/24/2023]
Abstract
Calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2) is a serine/threonine-protein kinase, that is involved in maintaining various physiological and cellular processes within the cell that regulate energy homeostasis and cell growth. CaMKK2 regulates glucose metabolism by the activation of downstream kinases, AMP-activated protein kinase (AMPK) and other calcium/calmodulin-dependent protein kinases. Consequently, its deregulation has a role in multiple human metabolic diseases including obesity and cancer. Despite the importance of CaMKK2, its signalling pathways and pathological mechanisms are not completely understood. Recent work has been aimed at broadening our understanding of the biological functions of CaMKK2. These studies have uncovered new interaction partners that have led to the description of new functions that include lipogenesis and Golgi vesicle trafficking. Here, we review recent insights into the role of CaMKK2 in membrane trafficking mechanisms and discuss the functional implications in a cellular context and for disease.
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8
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Guo Z, Zhang H, Liu X, Zhao Y, Chen Y, Jin J, Guo C, Zhang M, Gu F, Ma Y. Water channel protein AQP1 in cytoplasm is a critical factor in breast cancer local invasion. J Exp Clin Cancer Res 2023; 42:49. [PMID: 36803413 PMCID: PMC9940370 DOI: 10.1186/s13046-023-02616-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 02/02/2023] [Indexed: 02/21/2023] Open
Abstract
BACKGROUND Metastasis of breast cancer grows from the local invasion to the distant colonization. Blocking the local invasion step would be promising for breast cancer treatment. Our present study demonstrated AQP1 was a crucial target in breast cancer local invasion. METHODS Mass spectrometry combined with bioinformatics analysis was used to identify AQP1 associated proteins ANXA2 and Rab1b. Co-immunoprecipitation, immunofluorescence assays and cell functional experiments were carried out to define the relationship among AQP1, ANXA2 and Rab1b and their re-localization in breast cancer cells. The Cox proportional hazards regression model was performed toward the identification of relevant prognostic factors. Survival curves were plotted by the Kaplan-Meier method and compared by the log-rank test. RESULTS Here, we show that the cytoplasmic water channel protein AQP1, a crucial target in breast cancer local invasion, recruited ANXA2 from the cellular membrane to the Golgi apparatus, promoted Golgi apparatus extension, and induced breast cancer cell migration and invasion. In addition, cytoplasmic AQP1 recruited cytosolic free Rab1b to the Golgi apparatus to form a ternary complex containing AQP1, ANXA2, and Rab1b, which induced cellular secretion of the pro-metastatic proteins ICAM1 and CTSS. Cellular secretion of ICAM1 and CTSS led to the migration and invasion of breast cancer cells. Both in vivo assay and clinical analysis data confirmed above results. CONCLUSIONS Our findings suggested a novel mechanism for AQP1-induced breast cancer local invasion. Therefore, targeting AQP1 offers promises in breast cancer treatment.
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Affiliation(s)
- Zhifang Guo
- grid.411918.40000 0004 1798 6427Department of Tumor Cell Biology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Huanhu West Road, Hexi District, Tianjin, 300060 People’s Republic of China ,grid.411918.40000 0004 1798 6427Tianjin’s Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China ,grid.411918.40000 0004 1798 6427Key Laboratory of Cancer Prevention and Therapy, Tianjin, China ,grid.265021.20000 0000 9792 1228Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, China
| | - Huikun Zhang
- grid.411918.40000 0004 1798 6427Department of Tumor Cell Biology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Huanhu West Road, Hexi District, Tianjin, 300060 People’s Republic of China ,grid.411918.40000 0004 1798 6427Tianjin’s Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China ,grid.411918.40000 0004 1798 6427Key Laboratory of Cancer Prevention and Therapy, Tianjin, China ,grid.265021.20000 0000 9792 1228Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, China
| | - Xiaoli Liu
- grid.411918.40000 0004 1798 6427Department of Tumor Cell Biology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Huanhu West Road, Hexi District, Tianjin, 300060 People’s Republic of China ,grid.411918.40000 0004 1798 6427Tianjin’s Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China ,grid.411918.40000 0004 1798 6427Key Laboratory of Cancer Prevention and Therapy, Tianjin, China ,grid.265021.20000 0000 9792 1228Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, China
| | - Yawen Zhao
- grid.411918.40000 0004 1798 6427Department of Tumor Cell Biology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Huanhu West Road, Hexi District, Tianjin, 300060 People’s Republic of China ,grid.411918.40000 0004 1798 6427Tianjin’s Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China ,grid.411918.40000 0004 1798 6427Key Laboratory of Cancer Prevention and Therapy, Tianjin, China ,grid.265021.20000 0000 9792 1228Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, China
| | - Yongzi Chen
- grid.411918.40000 0004 1798 6427Department of Tumor Cell Biology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Huanhu West Road, Hexi District, Tianjin, 300060 People’s Republic of China ,grid.411918.40000 0004 1798 6427Tianjin’s Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China ,grid.411918.40000 0004 1798 6427Key Laboratory of Cancer Prevention and Therapy, Tianjin, China ,grid.265021.20000 0000 9792 1228Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, China
| | - Jiaqi Jin
- grid.411918.40000 0004 1798 6427Department of Tumor Cell Biology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Huanhu West Road, Hexi District, Tianjin, 300060 People’s Republic of China ,grid.411918.40000 0004 1798 6427Tianjin’s Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China ,grid.411918.40000 0004 1798 6427Key Laboratory of Cancer Prevention and Therapy, Tianjin, China ,grid.265021.20000 0000 9792 1228Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, China
| | - Caixia Guo
- grid.410726.60000 0004 1797 8419CAS Key Laboratory of Genomics and Precision Medicine, Beijing Institute of Genomics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, China National Center for Bioinformation, Beijing, 100101 China
| | - Ming Zhang
- grid.213876.90000 0004 1936 738XDepartment of Epidemiology and Biostatistics, University of Georgia, Athens, GA USA
| | - Feng Gu
- grid.411918.40000 0004 1798 6427Tianjin’s Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China ,grid.411918.40000 0004 1798 6427Key Laboratory of Cancer Prevention and Therapy, Tianjin, China ,grid.265021.20000 0000 9792 1228Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, China ,grid.411918.40000 0004 1798 6427Department of Breast Cancer Pathology and Research Laboratory, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China
| | - Yongjie Ma
- Department of Tumor Cell Biology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Huanhu West Road, Hexi District, Tianjin, 300060, People's Republic of China. .,Tianjin's Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China. .,Key Laboratory of Cancer Prevention and Therapy, Tianjin, China. .,Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, China.
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Ritter DJ, Choudhary D, Unlu G, Knapik EW. Rgp1 contributes to craniofacial cartilage development and Rab8a-mediated collagen II secretion. Front Endocrinol (Lausanne) 2023; 14:1120420. [PMID: 36843607 PMCID: PMC9947155 DOI: 10.3389/fendo.2023.1120420] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 01/24/2023] [Indexed: 02/11/2023] Open
Abstract
Rgp1 was previously identified as a component of a guanine nucleotide exchange factor (GEF) complex to activate Rab6a-mediated trafficking events in and around the Golgi. While the role of Rgp1 in protein trafficking has been examined in vitro and in yeast, the role of Rgp1 during vertebrate embryogenesis and protein trafficking in vivo is unknown. Using genetic, CRISPR-induced zebrafish mutants for Rgp1 loss-of-function, we found that Rgp1 is required for craniofacial cartilage development. Within live rgp1-/- craniofacial chondrocytes, we observed altered movements of Rab6a+ vesicular compartments, consistent with a conserved mechanism described in vitro. Using transmission electron microscopy (TEM) and immunofluorescence analyses, we show that Rgp1 plays a role in the secretion of collagen II, the most abundant protein in cartilage. Our overexpression experiments revealed that Rab8a is a part of the post-Golgi collagen II trafficking pathway. Following loss of Rgp1, chondrocytes activate an Arf4b-mediated stress response and subsequently respond with nuclear DNA fragmentation and cell death. We propose that an Rgp1-regulated Rab6a-Rab8a pathway directs secretion of ECM cargoes such as collagen II, a pathway that may also be utilized in other tissues where coordinated trafficking and secretion of collagens and other large cargoes is required for normal development and tissue function.
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Affiliation(s)
- Dylan J. Ritter
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, United States
- Division of Genetic Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Dharmendra Choudhary
- Division of Genetic Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Gokhan Unlu
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, United States
- Division of Genetic Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Ela W. Knapik
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, United States
- Division of Genetic Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
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10
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De Falco F, Cutarelli A, Catoi AF, Uberti BD, Cuccaro B, Roperto S. Bovine delta papillomavirus E5 oncoprotein negatively regulates the cGAS-STING signaling pathway in cattle in a spontaneous model of viral disease. Front Immunol 2022; 13:937736. [PMID: 36311756 PMCID: PMC9597257 DOI: 10.3389/fimmu.2022.937736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 09/27/2022] [Indexed: 11/19/2022] Open
Abstract
Persistent infection and tumorigenesis by papillomaviruses (PVs) require viral manipulation of various cellular processes, including those involved in innate immune responses. The cyclic guanosine monophosphate-adenosine monophosphate synthase-stimulator of interferon genes (cGAS-STING) pathway has emerged as an essential innate immune sensing system, that recognizes DNA and trigger potent antiviral effector responses. In this study, we found that bovine PV (BPV) E5 protein, the major oncoprotein of bovine delta PVs, interacts with STING but not with cGAS in a spontaneous BPV infection of neoplastic urothelial cells of cattle. Real-time RT-PCR revealed a significant reduction in both cGAS and STING transcripts in E5-expressing cells. Furthermore, western blot (WB) analysis failed to detect any variation in the expression of interferon-inducible protein 16 (IFI16), an upstream effector of the STING pathway. A ternary complex composed of E5/STING/IFI16 was also observed. Co-immunoprecipitation studies showed that STING interacts with a protein network composed of total and phosphorylated TANK-binding kinase 1 (TBK1), total and phosphorylated interferon regulatory factor 3 (IRF3), IRF7, IKKα, IKKβ, IKKϵ, ELKS, MEKK3, and TAK1. RT-qPCR revealed a significant reduction in TBK1 mRNA levels in BPV-infected cells. WB analysis revealed significantly reduced expression levels of pTBK1, which is essential for the activation and phosphorylation of IRF3, a prerequisite for the latter to enter the nucleus to activate type 1 IFN genes. WB also revealed significantly down-expression of IKKα, IKKβ, IKKϵ, and overexpression of IRF7, ELKS, MEKK3, and TAK1in BPV-positive urothelial cells compared with that in uninfected healthy cells. Phosphorylated p65 (p-p65) was significantly reduced in both the nuclear and cytosolic compartments of BPV-infected cells compared with that in uninfected urothelial cells. Our results suggest that the innate immune signaling pathway mediated by cGAS-STING is impaired in cells infected with BPV. Therefore, effective immune responses are not elicited against these viruses, which facilitates persistent viral infection and subsequent tumorigenesis.
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Affiliation(s)
- Francesca De Falco
- Dipartimento di Medicina Veterinaria e Produzioni Animali, Università degli Studi di Napoli Federico II, Napoli, Italy
| | - Anna Cutarelli
- Istituto Zooprofilattico Sperimentale del Mezzogiorno, Portici, Italy
| | - Adriana Florinela Catoi
- Physiopathology Department, Faculty of Medicine “Iuliu Hatieganu”, University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | | | - Bianca Cuccaro
- Dipartimento di Medicina Veterinaria e Produzioni Animali, Università degli Studi di Napoli Federico II, Napoli, Italy
| | - Sante Roperto
- Dipartimento di Medicina Veterinaria e Produzioni Animali, Università degli Studi di Napoli Federico II, Napoli, Italy
- *Correspondence: Sante Roperto,
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11
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Page KM, McCormack JJ, Lopes-da-Silva M, Patella F, Harrison-Lavoie K, Burden JJ, Quah YYB, Scaglioni D, Ferraro F, Cutler DF. Structure modeling hints at a granular organization of the Golgi ribbon. BMC Biol 2022; 20:111. [PMID: 35549945 PMCID: PMC9102599 DOI: 10.1186/s12915-022-01305-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 04/21/2022] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND In vertebrate cells, the Golgi functional subunits, mini-stacks, are linked into a tri-dimensional network. How this "ribbon" architecture relates to Golgi functions remains unclear. Are all connections between mini-stacks equal? Is the local structure of the ribbon of functional importance? These are difficult questions to address, without a quantifiable readout of the output of ribbon-embedded mini-stacks. Endothelial cells produce secretory granules, the Weibel-Palade bodies (WPB), whose von Willebrand Factor (VWF) cargo is central to hemostasis. The Golgi apparatus controls WPB size at both mini-stack and ribbon levels. Mini-stack dimensions delimit the size of VWF "boluses" whilst the ribbon architecture allows their linear co-packaging, thereby generating WPBs of different lengths. This Golgi/WPB size relationship suits mathematical analysis. RESULTS WPB lengths were quantized as multiples of the bolus size and mathematical modeling simulated the effects of different Golgi ribbon organizations on WPB size, to be compared with the ground truth of experimental data. An initial simple model, with the Golgi as a single long ribbon composed of linearly interlinked mini-stacks, was refined to a collection of mini-ribbons and then to a mixture of mini-stack dimers plus long ribbon segments. Complementing these models with cell culture experiments led to novel findings. Firstly, one-bolus sized WPBs are secreted faster than larger secretory granules. Secondly, microtubule depolymerization unlinks the Golgi into equal proportions of mini-stack monomers and dimers. Kinetics of binding/unbinding of mini-stack monomers underpinning the presence of stable dimers was then simulated. Assuming that stable mini-stack dimers and monomers persist within the ribbon resulted in a final model that predicts a "breathing" arrangement of the Golgi, where monomer and dimer mini-stacks within longer structures undergo continuous linking/unlinking, consistent with experimentally observed WPB size distributions. CONCLUSIONS Hypothetical Golgi organizations were validated against a quantifiable secretory output. The best-fitting Golgi model, accounting for stable mini-stack dimers, is consistent with a highly dynamic ribbon structure, capable of rapid rearrangement. Our modeling exercise therefore predicts that at the fine-grained level the Golgi ribbon is more complex than generally thought. Future experiments will confirm whether such a ribbon organization is endothelial-specific or a general feature of vertebrate cells.
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Affiliation(s)
- Karen M. Page
- Department of Mathematics, University College London, Gower Street, London, WC1E 6BT UK
| | - Jessica J. McCormack
- MRC Laboratory for Molecular cell Biology, University College London, Gower Street, London, WC1E 6BT UK
| | - Mafalda Lopes-da-Silva
- MRC Laboratory for Molecular cell Biology, University College London, Gower Street, London, WC1E 6BT UK
- Current address: iNOVA4Health, CEDOC-Chronic Diseases Research Center, NOVA Medical School, Universidade Nova de Lisboa, 1169-056 Lisboa, Portugal
| | - Francesca Patella
- MRC Laboratory for Molecular cell Biology, University College London, Gower Street, London, WC1E 6BT UK
- Current address: Kinomica, Alderley Park, Alderley Edge, Macclesfield, SK10 4TG UK
| | - Kimberly Harrison-Lavoie
- MRC Laboratory for Molecular cell Biology, University College London, Gower Street, London, WC1E 6BT UK
| | - Jemima J. Burden
- MRC Laboratory for Molecular cell Biology, University College London, Gower Street, London, WC1E 6BT UK
| | - Ying-Yi Bernadette Quah
- MRC Laboratory for Molecular cell Biology, University College London, Gower Street, London, WC1E 6BT UK
| | - Dominic Scaglioni
- MRC Laboratory for Molecular cell Biology, University College London, Gower Street, London, WC1E 6BT UK
| | - Francesco Ferraro
- Department of Biology and Evolution of Marine Organisms, BEOM, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy
| | - Daniel F. Cutler
- MRC Laboratory for Molecular cell Biology, University College London, Gower Street, London, WC1E 6BT UK
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12
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Nakano A. The Golgi Apparatus and its Next-Door Neighbors. Front Cell Dev Biol 2022; 10:884360. [PMID: 35573670 PMCID: PMC9096111 DOI: 10.3389/fcell.2022.884360] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Accepted: 03/28/2022] [Indexed: 12/20/2022] Open
Abstract
The Golgi apparatus represents a central compartment of membrane traffic. Its apparent architecture, however, differs considerably among species, from unstacked and scattered cisternae in the budding yeast Saccharomyces cerevisiae to beautiful ministacks in plants and further to gigantic ribbon structures typically seen in mammals. Considering the well-conserved functions of the Golgi, its fundamental structure must have been optimized despite seemingly different architectures. In addition to the core layers of cisternae, the Golgi is usually accompanied by next-door compartments on its cis and trans sides. The trans-Golgi network (TGN) can be now considered as a compartment independent from the Golgi stack. On the cis side, the intermediate compartment between the ER and the Golgi (ERGIC) has been known in mammalian cells, and its functional equivalent is now suggested for yeast and plant cells. High-resolution live imaging is extremely powerful for elucidating the dynamics of these compartments and has revealed amazing similarities in their behaviors, indicating common mechanisms conserved along the long course of evolution. From these new findings, I would like to propose reconsideration of compartments and suggest a new concept to describe their roles comprehensively around the Golgi and in the post-Golgi trafficking.
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13
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Maintaining Golgi Homeostasis: A Balancing Act of Two Proteolytic Pathways. Cells 2022; 11:cells11050780. [PMID: 35269404 PMCID: PMC8909885 DOI: 10.3390/cells11050780] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 02/18/2022] [Accepted: 02/21/2022] [Indexed: 02/06/2023] Open
Abstract
The Golgi apparatus is a central hub for cellular protein trafficking and signaling. Golgi structure and function is tightly coupled and undergoes dynamic changes in health and disease. A crucial requirement for maintaining Golgi homeostasis is the ability of the Golgi to target aberrant, misfolded, or otherwise unwanted proteins to degradation. Recent studies have revealed that the Golgi apparatus may degrade such proteins through autophagy, retrograde trafficking to the ER for ER-associated degradation (ERAD), and locally, through Golgi apparatus-related degradation (GARD). Here, we review recent discoveries in these mechanisms, highlighting the role of the Golgi in maintaining cellular homeostasis.
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14
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Small GTPases of the Rab and Arf Families: Key Regulators of Intracellular Trafficking in Neurodegeneration. Int J Mol Sci 2021; 22:ijms22094425. [PMID: 33922618 PMCID: PMC8122874 DOI: 10.3390/ijms22094425] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 04/14/2021] [Accepted: 04/20/2021] [Indexed: 12/11/2022] Open
Abstract
Small guanosine triphosphatases (GTPases) of the Rab and Arf families are key regulators of vesicle formation and membrane trafficking. Membrane transport plays an important role in the central nervous system. In this regard, neurons require a constant flow of membranes for the correct distribution of receptors, for the precise composition of proteins and organelles in dendrites and axons, for the continuous exocytosis/endocytosis of synaptic vesicles and for the elimination of dysfunctional proteins. Thus, it is not surprising that Rab and Arf GTPases have been associated with neurodegenerative diseases such as Alzheimer’s and Parkinson’s. Both pathologies share characteristics such as the presence of protein aggregates and/or the fragmentation of the Golgi apparatus, hallmarks that have been related to both Rab and Arf GTPases functions. Despite their relationship with neurodegenerative disorders, very few studies have focused on the role of these GTPases in the pathogenesis of neurodegeneration. In this review, we summarize their importance in the onset and progression of Alzheimer’s and Parkinson’s diseases, as well as their emergence as potential therapeutical targets for neurodegeneration.
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15
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Lu Q, Wang PS, Yang L. Golgi-associated Rab GTPases implicated in autophagy. Cell Biosci 2021; 11:35. [PMID: 33557950 PMCID: PMC7869216 DOI: 10.1186/s13578-021-00543-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 01/18/2021] [Indexed: 12/24/2022] Open
Abstract
Autophagy is a conserved cellular degradation process in eukaryotes that facilitates the recycling and reutilization of damaged organelles and compartments. It plays a pivotal role in cellular homeostasis, pathophysiological processes, and diverse diseases in humans. Autophagy involves dynamic crosstalk between different stages associated with intracellular vesicle trafficking. Golgi apparatus is the central organelle involved in intracellular vesicle trafficking where Golgi-associated Rab GTPases function as important mediators. This review focuses on the recent findings that highlight Golgi-associated Rab GTPases as master regulators of autophagic flux. The scope for future research in elucidating the role and mechanism of Golgi-associated Rab GTPases in autophagy and autophagy-related diseases is discussed further.
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Affiliation(s)
- Qingchun Lu
- Department of Medical Genetics and Molecular Biochemistry, Lewis Katz School of Medicine at Temple University, 3440 N Broad St, Kresge Hall, Rm. 624, Philadelphia, PA19140, USA
| | - Po-Shun Wang
- Department of Medical Genetics and Molecular Biochemistry, Lewis Katz School of Medicine at Temple University, 3440 N Broad St, Kresge Hall, Rm. 624, Philadelphia, PA19140, USA
| | - Ling Yang
- Department of Medical Genetics and Molecular Biochemistry, Lewis Katz School of Medicine at Temple University, 3440 N Broad St, Kresge Hall, Rm. 624, Philadelphia, PA19140, USA.
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16
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Rab6 is required for rapid, cisternal-specific, intra-Golgi cargo transport. Sci Rep 2020; 10:16604. [PMID: 33024151 PMCID: PMC7538953 DOI: 10.1038/s41598-020-73276-w] [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: 01/07/2020] [Accepted: 08/28/2020] [Indexed: 11/08/2022] Open
Abstract
Rab6, the most abundant Golgi associated small GTPase, consists of 2 equally common isoforms, Rab6A and Rab6A′, that differ in 3 amino acids and localize to trans Golgi cisternae. The two isoforms are largely redundant in function and hence are often referred to generically as Rab6. Rab6 loss-of-function inhibits retrograde Golgi trafficking, induces an increase in Golgi cisternal number in HeLa cells and delays the cell surface appearance of the anterograde cargo protein, VSVG. We hypothesized that these effects are linked and might be explained by a cisternal-specific delay in cargo transport. In pulse chase experiments using a deconvolved, confocal line scanning approach to score the distribution of the tsO45 mutant of VSVG protein in Rab6 depleted cells, we found that anterograde transport at 32 °C, permissive conditions, through the Golgi apparatus was locally delayed, almost tenfold, between medial and trans Golgi cisterna. Cis to medial transport was nearly normal as was trans Golgi to TGN transport. TGN exit was unaffected by Rab6 depletion. These effects were the same with either of two siRNAs. Similar intra-Golgi transport delays were seen at 37 °C with RUSH VSVG or a RUSH GPI-anchored construct using a biotin pulse to release the marker proteins from the ER. Using 3D-SIM, a super resolution approach, we found that RUSH VSVG transport was delayed pre-trans Golgi. These visual approaches suggest a selective slowing of anterograde transport relative to 3 different marker proteins downstream of the trans Golgi. Using a biochemical approach, we found that the onset of VSVG endoglycosidase H resistance in Rab6 depleted cells was delayed. Depletion of neither Rab6A or Rab6A′ isoforms alone had any effect on anterograde transport through the Golgi suggesting that Rab6A and Rab6A′ act coordinately. Delayed cargo transport conditions correlate strongly with a proliferation of Golgi cisternae observed in earlier electron microscopy. Our results strongly indicate that Rab6 is selectively required for rapid anterograde transport from the medial to trans Golgi. We suggest that the observed correlation with localized cisternal proliferation fits best with a cisternal progression model of Golgi function.
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17
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Herrera A, Muroski J, Sengupta R, Nguyen HH, Agarwal S, Ogorzalek Loo RR, Mattoo S, Loo JA, Satchell KJF. N-terminal autoprocessing and acetylation of multifunctional-autoprocessing repeats-in-toxins (MARTX) Makes Caterpillars Floppy-like effector is stimulated by adenosine diphosphate (ADP)-Ribosylation Factor 1 in advance of Golgi fragmentation. Cell Microbiol 2019; 22:e13133. [PMID: 31658406 DOI: 10.1111/cmi.13133] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 09/26/2019] [Accepted: 10/11/2019] [Indexed: 12/17/2022]
Abstract
Studies have successfully elucidated the mechanism of action of several effector domains that comprise the multifunctional-autoprocessing repeats-in-toxins (MARTX) toxins of Vibrio vulnificus. However, the biochemical linkage between the cysteine proteolytic activity of Makes Caterpillars Floppy (MCF)-like effector and its cellular effects remains unknown. In this study, we identify the host cell factors that activate in vivo and in vitro MCF autoprocessing as adenosine diphosphate (ADP)-Ribosylation Factor 1 (ARF1) and ADP-Ribosylation Factor 3 (ARF3). Autoprocessing activity is enhanced when ARF1 is in its active [guanosine triphosphate (GTP)-bound] form compared to the inactive [guanosine diphosphate (GDP)-bound] form. Subsequent to auto-cleavage, MCF is acetylated on its exposed N-terminal glycine residue. Acetylation apparently does not dictate subcellular localization as MCF is found localized throughout the cell. However, the cleaved form of MCF gains the ability to bind to the specialized lipid phosphatidylinositol 5-phosphate enriched in Golgi and other membranes necessary for endocytic trafficking, suggesting that a fraction of MCF may be subcellularly localized. Traditional thin-section electron microscopy, high-resolution cryoAPEX localization, and fluorescent microscopy show that MCF causes Golgi dispersal resulting in extensive vesiculation. In addition, host mitochondria are disrupted and fragmented. Mass spectrometry analysis found no reproducible modifications of ARF1 suggesting that ARF1 is not post-translationally modified by MCF. Further, catalytically active MCF does not stably associate with ARF1. Our data indicate not only that ARF1 is a cross-kingdom activator of MCF, but also that MCF may mediate cytotoxicity by directly targeting another yet to be identified protein. This study begins to elucidate the biochemical activity of this important domain and gives insight into how it may promote disease progression.
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Affiliation(s)
- Alfa Herrera
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - John Muroski
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California
| | - Ranjan Sengupta
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana
| | - Hong Hanh Nguyen
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California
| | - Shivangi Agarwal
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Rachel R Ogorzalek Loo
- Department of Biological Chemistry, David Geffen School of Medicine, UCLA Molecular Biology Institute, University of California-Los Angeles, Los Angeles, California.,UCLA/DOE Institute of Genomics and Proteomics, University of California-Los Angeles, Los Angeles, California
| | - Seema Mattoo
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana.,Purdue Institute for Inflammation, Immunology and Infectious Diseases, Purdue University, West Lafayette, Indiana
| | - Joseph A Loo
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California.,Department of Biological Chemistry, David Geffen School of Medicine, UCLA Molecular Biology Institute, University of California-Los Angeles, Los Angeles, California
| | - Karla J F Satchell
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
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18
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Lyu C, Cai X. A GFP-tagged version of the pseudorabies virus protein UL56 localizes to the Golgi and trans-Golgi network through a predicted C-terminal leucine-rich helix in transfected cells. Virol J 2019; 16:81. [PMID: 31221185 PMCID: PMC6585060 DOI: 10.1186/s12985-019-1191-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 06/12/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Pseudorabies virus (PRV) protein UL56 (pUL56) has been implicated in viral dissemination and virulence in vivo. However, the properties of PRV pUL56 remain largely unknown. In the present study, we aim to investigate the subcellular localization of pUL56 and the underlying molecular basis in transfected cells. METHODS Constructs of N-terminal green fluorescent protein (GFP) fused pUL56 and its truncations were employed for investigating subcellular localization and further identifying amino acids crucial for pUL56 localization in transfected Vero cells. Finally, the identified amino acids were replaced with alanine for confirming if these mutations could impair the specific localization of pUL56. RESULTS The pUL56 predominantly localized at the Golgi and trans-Golgi network (TGN) through its predicted C-terminal transmembrane helix in transfected Vero cells. A Golgi-associated protein Rab6a, independent of interaction with pUL56, was significantly downregulated by pUL56. Further, we found three truncated pUL56 C-terminal fragments (174-184, 175-185 and 191-195) could restrict GFP in the perinuclear region, respectively. Within these truncations, the 174proline (P), 181leucine (L), 185L and 191L were essential for maintaining perinuclear accumulation, thus suggesting an important role of leucine. Alanine (A) mutagenesis assays were employed to generate a series of pUL56 C-terminal mutants on the basis of leucine. Finally, a pUL56 mutant M10 (174P/A-177L/A-181L/A-185L/A-191L/A-194L/A-195I/A-196-197L/A-200L/A) lost Golgi-TGN localization. Thus, our data revealed that the leucine-rich transmembrane helix was responsible for pUL56 Golgi-TGN localization and retention, probably through specific intracellular membrane insertion. CONCLUSION Our data indicated that the C-terminal transmembrane helix was responsible for the Golgi-TGN localization of pUL56. In addition, the leucines within C-terminal transmembrane helix were essential for maintaining pUL56 Golgi-TGN retention in cells. Further, the pUL56 can induce downregulation of Golgi-associated protein Rab6a.
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Affiliation(s)
- Chuang Lyu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Haping Road No.678, Xiang Fang District, Harbin, 150069, Heilongjiang, China
| | - Xuehui Cai
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Haping Road No.678, Xiang Fang District, Harbin, 150069, Heilongjiang, China.
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19
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Rasika S, Passemard S, Verloes A, Gressens P, El Ghouzzi V. Golgipathies in Neurodevelopment: A New View of Old Defects. Dev Neurosci 2019; 40:396-416. [PMID: 30878996 DOI: 10.1159/000497035] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 01/16/2019] [Indexed: 11/19/2022] Open
Abstract
The Golgi apparatus (GA) is involved in a whole spectrum of activities, from lipid biosynthesis and membrane secretion to the posttranslational processing and trafficking of most proteins, the control of mitosis, cell polarity, migration and morphogenesis, and diverse processes such as apoptosis, autophagy, and the stress response. In keeping with its versatility, mutations in GA proteins lead to a number of different disorders, including syndromes with multisystem involvement. Intriguingly, however, > 40% of the GA-related genes known to be associated with disease affect the central or peripheral nervous system, highlighting the critical importance of the GA for neural function. We have previously proposed the term "Golgipathies" in relation to a group of disorders in which mutations in GA proteins or their molecular partners lead to consequences for brain development, in particular postnatal-onset microcephaly (POM), white-matter defects, and intellectual disability (ID). Here, taking into account the broader role of the GA in the nervous system, we refine and enlarge this emerging concept to include other disorders whose symptoms may be indicative of altered neurodevelopmental processes, from neurogenesis to neuronal migration and the secretory function critical for the maturation of postmitotic neurons and myelination.
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Affiliation(s)
- Sowmyalakshmi Rasika
- NeuroDiderot, INSERM UMR1141, Université Paris Diderot, Sorbonne Paris Cité, Paris, France.,AP HP, Hôpital Robert Debré, UF de Génétique Clinique, Paris, France
| | - Sandrine Passemard
- NeuroDiderot, INSERM UMR1141, Université Paris Diderot, Sorbonne Paris Cité, Paris, France.,AP HP, Hôpital Robert Debré, UF de Génétique Clinique, Paris, France
| | - Alain Verloes
- NeuroDiderot, INSERM UMR1141, Université Paris Diderot, Sorbonne Paris Cité, Paris, France.,AP HP, Hôpital Robert Debré, UF de Génétique Clinique, Paris, France
| | - Pierre Gressens
- NeuroDiderot, INSERM UMR1141, Université Paris Diderot, Sorbonne Paris Cité, Paris, France.,Centre for the Developing Brain, Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London, United Kingdom
| | - Vincent El Ghouzzi
- NeuroDiderot, INSERM UMR1141, Université Paris Diderot, Sorbonne Paris Cité, Paris, France,
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20
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Abstract
The Golgi apparatus is a central intracellular membrane-bound organelle with key functions in trafficking, processing, and sorting of newly synthesized membrane and secretory proteins and lipids. To best perform these functions, Golgi membranes form a unique stacked structure. The Golgi structure is dynamic but tightly regulated; it undergoes rapid disassembly and reassembly during the cell cycle of mammalian cells and is disrupted under certain stress and pathological conditions. In the past decade, significant amount of effort has been made to reveal the molecular mechanisms that regulate the Golgi membrane architecture and function. Here we review the major discoveries in the mechanisms of Golgi structure formation, regulation, and alteration in relation to its functions in physiological and pathological conditions to further our understanding of Golgi structure and function in health and diseases.
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Affiliation(s)
- Jie Li
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Erpan Ahat
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Yanzhuang Wang
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA.
- Department of Neurology, University of Michigan School of Medicine, Ann Arbor, MI, USA.
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21
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Abstract
The Golgi apparatus is a central sorting station in the cell. It receives newly synthesized molecules from the endoplasmic reticulum and directs them to different subcellular destinations, such as the plasma membrane or the endocytic pathway. Importantly, in the last few years, it has emerged that the maintenance of Golgi structure is connected to the proper regulation of membrane trafficking. Rab proteins are small GTPases that are considered to be the master regulators of the intracellular membrane trafficking. Several of the over 60 human Rabs are involved in the regulation of transport pathways at the Golgi as well as in the maintenance of its architecture. This chapter will summarize the different roles of Rab GTPases at the Golgi, both as regulators of membrane transport, scaffold, and tethering proteins and in preserving the structure and function of this organelle.
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22
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Prince E, Kroeger B, Gligorov D, Wilson C, Eaton S, Karch F, Brankatschk M, Maeda RK. Rab-mediated trafficking in the secondary cells of Drosophila male accessory glands and its role in fecundity. Traffic 2018; 20:137-151. [PMID: 30426623 PMCID: PMC6492190 DOI: 10.1111/tra.12622] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 11/01/2018] [Accepted: 11/06/2018] [Indexed: 12/16/2022]
Abstract
The male seminal fluid contains factors that affect female post‐mating behavior and physiology. In Drosophila, most of these factors are secreted by the two epithelial cell types that make up the male accessory gland: the main and secondary cells. Although secondary cells represent only ~4% of the cells of the accessory gland, their contribution to the male seminal fluid is essential for sustaining the female post‐mating response. To better understand the function of the secondary cells, we investigated their molecular organization, particularly with respect to the intracellular membrane transport machinery. We determined that large vacuole‐like structures found in the secondary cells are trafficking hubs labeled by Rab6, 7, 11 and 19. Furthermore, these organelles require Rab6 for their formation and many are essential in the process of creating the long‐term postmating behavior of females. In order to better serve the intracellular membrane and protein trafficking communities, we have created a searchable, online, open‐access imaging resource to display our complete findings regarding Rab localization in the accessory gland.
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Affiliation(s)
- Elodie Prince
- Department of Genetics and Evolution, Section of Biology, Sciences Faculty, University of Geneva, Geneva, Switzerland
| | - Benjamin Kroeger
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Dragan Gligorov
- Department of Genetics and Evolution, Section of Biology, Sciences Faculty, University of Geneva, Geneva, Switzerland
| | - Clive Wilson
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Suzanne Eaton
- Biotechnology Center of the TU Dresden, Dresden, Germany.,Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - François Karch
- Department of Genetics and Evolution, Section of Biology, Sciences Faculty, University of Geneva, Geneva, Switzerland
| | - Marko Brankatschk
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Robert K Maeda
- Department of Genetics and Evolution, Section of Biology, Sciences Faculty, University of Geneva, Geneva, Switzerland
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23
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Pan ZN, Lu Y, Tang F, Pan MH, Wan X, Lan M, Zhang Y, Sun SC. RAB8A GTPase regulates spindle migration and Golgi apparatus distribution via ROCK-mediated actin assembly in mouse oocyte meiosis†. Biol Reprod 2018; 100:711-720. [DOI: 10.1093/biolre/ioy217] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 09/03/2018] [Accepted: 09/30/2018] [Indexed: 12/13/2022] Open
Affiliation(s)
- Zhen-Nan Pan
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Yujie Lu
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Feng Tang
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Meng-Hao Pan
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiang Wan
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Mei Lan
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Yu Zhang
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Shao-Chen Sun
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
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24
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Cardoso R, Wang J, Müller J, Rupp S, Leitão A, Hemphill A. Modulation of cis- and trans- Golgi and the Rab9A-GTPase during infection by Besnoitia besnoiti, Toxoplasma gondii and Neospora caninum. Exp Parasitol 2018; 187:75-85. [PMID: 29499180 DOI: 10.1016/j.exppara.2018.02.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 01/08/2018] [Accepted: 02/26/2018] [Indexed: 01/08/2023]
Abstract
Like most intracellular pathogens, the apicomplexan parasites Besnoitia besnoiti, Toxoplasma gondii and Neospora caninum scavenge metabolites from their host cells. Recruitment of the Golgi complex to the vicinity of the parasitophorous vacuole (PV) is likely to aid in this process. In this work, we comparatively assessed B. besnoiti, T. gondii and N. caninum infected human retinal pigmented epithelial (hTERT-RPE-1) cells at 24 h post-infection and used antibodies to confirm Golgi ribbon compaction in B. besnoiti, and Golgi ribbon dispersion in T. gondii, while no alteration in Golgi morphology was seen in N. caninum infected cells. In either case, the Golgi stacks of infected cells contained both cis- (GM130) and trans- (TGN46) Golgi proteins. The localization of Rab9A, an important regulator of endosomal trafficking, was also studied. GFP-tagged Rab9A was recruited to the vicinity of the PV of all three parasites. Toxoplasma-infected cells exhibited increased expression of Rab9A in comparison to non-infected cells. However, Rab9A expression levels remained unaltered upon infection with N. caninum and B. besnoiti tachyzoites. In contrast to Rab9A, a GFP-tagged dominant negative mutant form of Rab9A (Rab9A DN), was not recruited to the PV, and the expression of Rab9A DN did not affect host cell invasion nor replication by all three parasites. Thus, B. besnoiti, T. gondii and N. caninum show similarities but also differences in how they affect constituents of the endosomal/secretory pathways.
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Affiliation(s)
- Rita Cardoso
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Länggassstrasse 122, Bern, 3012, Switzerland; Centro de Investigação Interdisciplinar em Sanidade Animal, Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477, Lisboa, Portugal.
| | - Junhua Wang
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Länggassstrasse 122, Bern, 3012, Switzerland
| | - Joachim Müller
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Länggassstrasse 122, Bern, 3012, Switzerland
| | - Sebastian Rupp
- Division of Neurological Sciences, Department of Clinical Research and Veterinary Public Health, Vetsuisse Faculty, University of Bern, Länggassstrasse 122, Bern, 3012, Switzerland; Graduate School for Cellular and Biomedical Sciences, Theodor Kocher Institute, University of Bern, Freiestrasse 1, Bern, 3012, Switzerland
| | - Alexandre Leitão
- Centro de Investigação Interdisciplinar em Sanidade Animal, Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477, Lisboa, Portugal
| | - Andrew Hemphill
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Länggassstrasse 122, Bern, 3012, Switzerland
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25
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Abstract
GTP-ases of the Rab family (about 70 in human) are key regulators of intracellular transport and membrane trafficking in eukaryotic cells. Remarkably, almost one third associate with membranes of the Golgi complex and TGN (trans-Golgi network). Through interactions with a variety of effectors that include molecular motors, tethering complexes, scaffolding proteins and lipid kinases, they play an important role in maintaining Golgi architecture.
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Affiliation(s)
- Bruno Goud
- a Institut Curie, PSL Research University, CNRS, UMR 144, Molecular Mechanisms of Intracellular Transport , Paris , France
| | - Shijie Liu
- b Department of Physiology and Biophysics , University of Arkansas for Medical Sciences , Little Rock , USA
| | - Brian Storrie
- b Department of Physiology and Biophysics , University of Arkansas for Medical Sciences , Little Rock , USA
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26
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Liu X, Wang Z, Yang Y, Li Q, Zeng R, Kang J, Wu J. Rab1A mediates proinsulin to insulin conversion in β-cells by maintaining Golgi stability through interactions with golgin-84. Protein Cell 2018; 7:692-6. [PMID: 27502188 PMCID: PMC5003788 DOI: 10.1007/s13238-016-0298-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Affiliation(s)
- Xiaojing Liu
- Key Laboratory of Systems Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
- Clinical and Translational Research Center of Shanghai First Maternity and Infant Health Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, Shanghai, 200092, China
| | - Zhenguo Wang
- Key Laboratory of Systems Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Ying Yang
- Key Laboratory of Systems Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Qingrun Li
- Key Laboratory of Systems Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Rong Zeng
- Key Laboratory of Systems Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Jiuhong Kang
- Clinical and Translational Research Center of Shanghai First Maternity and Infant Health Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, Shanghai, 200092, China
| | - Jiarui Wu
- Key Laboratory of Systems Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China.
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 200031, China.
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201210, China.
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27
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Fujimoto T, Kuwahara T, Eguchi T, Sakurai M, Komori T, Iwatsubo T. Parkinson's disease-associated mutant LRRK2 phosphorylates Rab7L1 and modifies trans-Golgi morphology. Biochem Biophys Res Commun 2017; 495:1708-1715. [PMID: 29223392 DOI: 10.1016/j.bbrc.2017.12.024] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 12/05/2017] [Indexed: 10/18/2022]
Abstract
Mutations in leucine-rich repeat kinase 2 (LRRK2) are the major genetic cause of autosomal-dominantly inherited Parkinson's disease. LRRK2 is implicated in the regulation of intracellular trafficking, neurite outgrowth and PD risk in connection with Rab7L1, a putative interactor of LRRK2. Recently, a subset of Rab GTPases have been reported as substrates of LRRK2. Here we examine the kinase activity of LRRK2 on Rab7L1 in situ in cells. Phos-tag analyses and metabolic labeling assays revealed that LRRK2 readily phosphorylates Golgi-localized wild-type Rab7L1 but not mutant forms that are distributed in the cytoplasm. In vitro assays demonstrated direct phosphorylation of Rab7L1 by LRRK2. Subsequent screening using Rab7L1 mutants harboring alanine-substitution for every single Ser/Thr residue revealed that Ser72 is a major phosphorylation site, which was confirmed by using a phospho-Ser72-specific antibody. Moreover, LRRK2 pathogenic Parkinson mutants altogether markedly enhanced the phosphorylation at Ser72. The modulation of Ser72 phosphorylation in Rab7L1 resulted in an alteration of the morphology and distribution of the trans-Golgi network. These data collectively support the involvement of Rab7L1 phosphorylation in the LRRK2-mediated cellular and pathogenetic mechanisms.
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Affiliation(s)
- Tetta Fujimoto
- Department of Neuropathology, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Tomoki Kuwahara
- Department of Neuropathology, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Tomoya Eguchi
- Department of Neuropathology, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Maria Sakurai
- Department of Neuropathology, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Tadayuki Komori
- Department of Neuropathology, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Takeshi Iwatsubo
- Department of Neuropathology, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan.
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28
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Shorter SA, Pettit MW, Dyer PDR, Coakley Youngs E, Gorringe-Pattrick MAM, El-Daher S, Richardson S. Green fluorescent protein (GFP): is seeing believing and is that enough? J Drug Target 2017; 25:809-817. [PMID: 28743200 DOI: 10.1080/1061186x.2017.1358725] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Intracellular compartmentalisation is a significant barrier to the successful nucleocytosolic delivery of biologics. The endocytic system has been shown to be responsible for compartmentalisation, providing an entry point, and trigger(s) for the activation of drug delivery systems. Consequently, many of the technologies used to understand endocytosis have found utility within the field of drug delivery. The use of fluorescent proteins as markers denoting compartmentalisation within the endocytic system has become commonplace. Several of the limitations associated with the use of green fluorescent protein (GFP) within the context of drug delivery have been explored here by asking a series of related questions: (1) Are molecules that regulate fusion to a specific compartment (i.e. Rab- or SNARE-GFP fusions) a good choice of marker for that compartment? (2) How reliable was GFP-marker overexpression when used to define a given endocytic compartment? (3) Can glutathione-s-transferase (GST) fused in frame with GFP (GST-GFP) act as a fluid phase endocytic probe? (4) Was GFP fluorescence a robust indicator of (GFP) protein integrity? This study concluded that there are many appropriate and useful applications for GFP; however, thought and an understanding of the biological and physicochemical character of these markers are required for the generation of meaningful data.
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Affiliation(s)
- Susan A Shorter
- a IDS Laboratory, Department of Life and Sports Science, Faculty of Engineering and Science , University of Greenwich , Chatham , Kent , UK
| | - Marie W Pettit
- a IDS Laboratory, Department of Life and Sports Science, Faculty of Engineering and Science , University of Greenwich , Chatham , Kent , UK
| | - Paul D R Dyer
- a IDS Laboratory, Department of Life and Sports Science, Faculty of Engineering and Science , University of Greenwich , Chatham , Kent , UK
| | - Emma Coakley Youngs
- a IDS Laboratory, Department of Life and Sports Science, Faculty of Engineering and Science , University of Greenwich , Chatham , Kent , UK
| | - Monique A M Gorringe-Pattrick
- a IDS Laboratory, Department of Life and Sports Science, Faculty of Engineering and Science , University of Greenwich , Chatham , Kent , UK
| | - Samer El-Daher
- a IDS Laboratory, Department of Life and Sports Science, Faculty of Engineering and Science , University of Greenwich , Chatham , Kent , UK
| | - Simon Richardson
- a IDS Laboratory, Department of Life and Sports Science, Faculty of Engineering and Science , University of Greenwich , Chatham , Kent , UK
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29
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Tau secretion is correlated to an increase of Golgi dynamics. PLoS One 2017; 12:e0178288. [PMID: 28552936 PMCID: PMC5446162 DOI: 10.1371/journal.pone.0178288] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Accepted: 05/10/2017] [Indexed: 01/07/2023] Open
Abstract
Tau protein can be released by neurons, an event linked to the propagation of Tau pathology in Alzheimer’disease (AD). Neuronal hyperexcitability was shown to significantly increase Tau release by neurons. We confirmed this in the present study. In a previous study, it was demonstrated that hyperexcitability induces Golgi apparatus dynamics resulting in its fragmentation. Our present results revealed that the increase of Tau secretion upon hyperexcitability could be significantly reduced by preventing Golgi dynamics through the inactivation of cdk5. We then verified whether a Golgi fragmentation not induced by hyperexcitability could also increase Tau secretion. The suppression of Rab1A, Rab GTPase associated with the Golgi membranes, known to induce a Golgi fragmentation increased Tau secretion by both neurons and HeLa cells. Although it remains to be demonstrated whether the Golgi is directly involved in Tau secretion, the present results demonstrate that its dynamics are correlated to a modulation of Tau secretion.
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30
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Dykstra KM, Allen C, Born EJ, Tong H, Holstein SA. Mechanisms for autophagy modulation by isoprenoid biosynthetic pathway inhibitors in multiple myeloma cells. Oncotarget 2016; 6:41535-49. [PMID: 26595805 PMCID: PMC4747172 DOI: 10.18632/oncotarget.6365] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 11/16/2015] [Indexed: 01/05/2023] Open
Abstract
Multiple myeloma (MM) is characterized by the production of monoclonal protein (MP). We have shown previously that disruption of the isoprenoid biosynthetic pathway (IBP) causes a block in MP secretion through a disruption of Rab GTPase activity, leading to an enhanced unfolded protein response and subsequent apoptosis in MM cells. Autophagy is induced by cellular stressors including nutrient deprivation and ER stress. IBP inhibitors have been shown to have disparate effects on autophagy. Here we define the mechanisms underlying the differential effects of IBP inhibitors on autophagic flux in MM cells utilizing specific pharmacological inhibitors. We demonstrate that IBP inhibition induces a net increase in autophagy as a consequence of disruption of isoprenoid biosynthesis which is not recapitulated by direct geranylgeranyl transferase inhibition. IBP inhibitor-induced autophagy is a cellular defense mechanism as treatment with the autophagy inhibitor bafilomycin A1 enhances the cytotoxic effects of GGPP depletion, but not geranylgeranyl transferase inhibition. Immunofluorescence microscopy studies revealed that IBP inhibitors disrupt ER to Golgi trafficking of monoclonal light chain protein and that this protein is not a substrate for alternative degradative pathways such as aggresomes and autophagosomes. These studies support further development of specific GGTase II inhibitors as anti-myeloma agents.
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Affiliation(s)
- Kaitlyn M Dykstra
- Department of Medicine, Roswell Park Cancer Institute, Buffalo, NY, USA
| | - Cheryl Allen
- Department of Medicine, Roswell Park Cancer Institute, Buffalo, NY, USA
| | - Ella J Born
- Department of Internal Medicine, University of Iowa, Iowa City, IA, USA
| | - Huaxiang Tong
- Penn State Hershey Cancer Institute, Hershey, PA, USA
| | - Sarah A Holstein
- Department of Medicine, Roswell Park Cancer Institute, Buffalo, NY, USA.,Department of Immunology, Roswell Park Cancer Institute, Buffalo, NY, USA
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31
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Abstract
Selective membrane transport pathways are essential for cells in situ to construct and maintain a polarized structure comprising multiple plasma membrane domains, which is essential for their specific cellular functions. Genetic screening in Drosophila photoreceptors harboring multiple plasma membrane domains enables the identification of genes involved in polarized transport pathways. Our genome-wide high-throughput screening identified a Rab6-null mutant with a rare phenotype characterized by a loss of 2 apical transport pathways with an intact basolateral transport. Although the functions of Rab6 in the Golgi apparatus are well known, its function in polarized transport is unexpected. The mutant phenotype and localization of Rab6 strongly indicate that Rab6 regulates transport between the trans-Golgi network (TGN) and recycling endosomes (REs): basolateral cargos are segregated at the TGN before Rab6 functions, but cargos going to multiple apical domains are sorted at REs. Both the medial-Golgi resident protein Metallophosphoesterase (MPPE) and the TGN marker GalT::CFP exhibit diffused co-localized distributions in Rab6-deficient cells, suggesting they are trapped in the retrograde transport vesicles returning to trans-Golgi cisternae. Hence, we propose that Rab6 regulates the fusion of retrograde transport vesicles containing medial, trans-Golgi resident proteins to the Golgi cisternae, which causes Golgi maturation to REs.
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Affiliation(s)
- Takunori Satoh
- a Division of Life Science, Graduate School of Integral Arts and Science, Hiroshima University , Higashi-Hiroshima , Japan
| | - Yuri Nakamura
- a Division of Life Science, Graduate School of Integral Arts and Science, Hiroshima University , Higashi-Hiroshima , Japan
| | - Akiko K Satoh
- a Division of Life Science, Graduate School of Integral Arts and Science, Hiroshima University , Higashi-Hiroshima , Japan
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32
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Saraste J. Spatial and Functional Aspects of ER-Golgi Rabs and Tethers. Front Cell Dev Biol 2016; 4:28. [PMID: 27148530 PMCID: PMC4834429 DOI: 10.3389/fcell.2016.00028] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 03/23/2016] [Indexed: 12/13/2022] Open
Abstract
Two conserved Rab GTPases, Rab1 and Rab2, play important roles in biosynthetic-secretory trafficking between the endoplasmic reticulum (ER) and the Golgi apparatus in mammalian cells. Both are expressed as two isoforms that regulate anterograde transport via the intermediate compartment (IC) to the Golgi, but are also required for transport in the retrograde direction. Moreover, Rab1 has been implicated in the formation of autophagosomes. Rab1 and Rab2 have numerous effectors or partners that function in membrane tethering, but also have other roles. These include the coiled-coil proteins p115, GM130, giantin, golgin-84, and GMAP-210, as well as the multisubunit COG (conserved oligomeric Golgi) and TRAPP (transport protein particle) tethering complexes. TRAPP also acts as the GTP exchange factor (GEF) in the activation of Rab1. According to the traditional view of the IC elements as motile, transient structures, the functions of the Rabs could take place at the two ends of the ER-Golgi itinerary, i.e., at ER exit sites (ERES) and/or cis-Golgi. However, there is considerable evidence for their specific association with the IC, including its recently identified pericentrosomal domain (pcIC), where many of the effectors turn out to be present, thus being able to exert their functions at the pre-Golgi level. The IC localization of these proteins is of particular interest based on the imaging of Rab1 dynamics, indicating that the IC is a stable organelle that bidirectionally communicates with the ER and Golgi, and is functionally linked to the endosomal system via the pcIC.
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Affiliation(s)
- Jaakko Saraste
- Department of Biomedicine and Molecular Imaging Center, University of Bergen Bergen, Norway
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33
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Liu S, Majeed W, Kudlyk T, Lupashin V, Storrie B. Identification of Rab41/6d Effectors Provides an Explanation for the Differential Effects of Rab41/6d and Rab6a/a' on Golgi Organization. Front Cell Dev Biol 2016; 4:13. [PMID: 26973836 PMCID: PMC4771738 DOI: 10.3389/fcell.2016.00013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 02/09/2016] [Indexed: 11/24/2022] Open
Abstract
Unexpectedly, members of the Rab VI subfamily exhibit considerable variation in their effects on Golgi organization and trafficking. By fluorescence microscopy, neither depletion nor overexpression of the GDP-locked form of Rab6a/a', the first trans Golgi-associated Rab protein discovered, affects Golgi ribbon organization while, on the other hand, both Rab41/6d depletion and overexpression of GDP-locked form cause Golgi fragmentation into a cluster of punctate elements, suggesting that Rab41/6d has an active role in maintenance of Golgi ribbon organization. To establish a molecular basis for these differences, we screened for Rab41/6d interacting proteins by yeast two-hybrid assay. 155 non-repetitive hits were isolated and sequenced, and after searching in NCBI database, 102 different proteins and protein fragments were identified. None of these hits overlapped with any published Rab6a/a' effector. Eight putative Rab41 interactors involved in membrane trafficking were found. Significantly, these exhibited a preferential interaction with GTP- vs. GDP-locked Rab41/6d. Of the 8 hits, the dynactin 6, syntaxin 8, and Kif18A plasmids were the only ones expressing the full-length protein. Hence, these 3 proteins were selected for further study. We found that depletion of dynactin 6 or syntaxin 8, but not Kif18A, resulted in a fragmented Golgi apparatus that displayed a Rab41/6d knockdown phenotype, i.e., the Golgi apparatus was disrupted into a cluster of punctate Golgi elements. Co-immunoprecipation experiments verified that the interaction of dynactin 6 and syntaxin 8 with GTP-locked Rab41/6d was stronger than that with wild type Rab41/6d and least with the GDP-locked form. In contrast, co-immunoprecipitation interaction with Rab6a was greatest with the GDP-locked Rab6a, suggestive of a non-physiological interaction. In conclusion, we suggest that dynactin 6, a subunit of dynactin complex, the minus-end-directed, dynein motor, provides a sufficient molecular basis to explain the active role of Rab41/6d in maintaining Golgi ribbon organization while syntaxin 8 contributes more indirectly to Golgi positioning.
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Affiliation(s)
- Shijie Liu
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences Little Rock, AR, USA
| | - Waqar Majeed
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences Little Rock, AR, USA
| | - Tetyana Kudlyk
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences Little Rock, AR, USA
| | - Vladimir Lupashin
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences Little Rock, AR, USA
| | - Brian Storrie
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences Little Rock, AR, USA
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34
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Iwanami N, Nakamura Y, Satoh T, Liu Z, Satoh AK. Rab6 Is Required for Multiple Apical Transport Pathways but Not the Basolateral Transport Pathway in Drosophila Photoreceptors. PLoS Genet 2016; 12:e1005828. [PMID: 26890939 PMCID: PMC4758697 DOI: 10.1371/journal.pgen.1005828] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Accepted: 01/05/2016] [Indexed: 11/30/2022] Open
Abstract
Polarized membrane trafficking is essential for the construction and maintenance of multiple plasma membrane domains of cells. Highly polarized Drosophila photoreceptors are an excellent model for studying polarized transport. A single cross-section of Drosophila retina contains many photoreceptors with 3 clearly differentiated plasma membrane domains: a rhabdomere, stalk, and basolateral membrane. Genome-wide high-throughput ethyl methanesulfonate screening followed by precise immunohistochemical analysis identified a mutant with a rare phenotype characterized by a loss of 2 apical transport pathways with normal basolateral transport. Rapid gene identification using whole-genome resequencing and single nucleotide polymorphism mapping identified a nonsense mutation of Rab6 responsible for the apical-specific transport deficiency. Detailed analysis of the trafficking of a major rhabdomere protein Rh1 using blue light-induced chromophore supply identified Rab6 as essential for Rh1 to exit the Golgi units. Rab6 is mostly distributed from the trans-Golgi network to a Golgi-associated Rab11-positive compartment that likely recycles endosomes or transport vesicles going to recycling endosomes. Furthermore, the Rab6 effector, Rich, is required for Rab6 recruitment in the trans-Golgi network. Moreover, a Rich null mutation phenocopies the Rab6 null mutant, indicating that Rich functions as a guanine nucleotide exchange factor for Rab6. The results collectively indicate that Rab6 and Rich are essential for the trans-Golgi network–recycling endosome transport of cargoes destined for 2 apical domains. However, basolateral cargos are sorted and exported from the trans-Golgi network in a Rab6-independent manner. Cells in animal bodies have multiple plasma membrane domains; this polarized characteristic of cells is essential for their specific functions. Selective membrane transport pathways play key roles in the construction and maintenance of polarized structures. Drosophila photoreceptors with multiple plasma membrane domains are an excellent model of polarized transport. We performed genetic screening and identified a Rab6 null mutant with a rare phenotype characterized by a loss of 2 apical transport pathways with normal basolateral transport. Although Rab6 functions in the Golgi are well known, its function in polarized transport was unexpected. Here, we found that Rab6 and its effector, Rich, are required for multiple apical transport pathways but not the basolateral transport pathway. Our findings strongly indicate that the membrane proteins delivered to multiple polarized domains are not sorted simultaneously: basolateral cargos are segregated before the Rab6-dependent process, and cargos going to multiple apical domains are sorted after Rab6-dependent transport from the trans-Golgi network to the Golgi-associated Rab11-positive compartment, which presumably recycles endosomes. Our finding of the function of Rab6 in polarized transport will elucidate the molecular mechanisms of polarized transport.
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Affiliation(s)
- Nozomi Iwanami
- Division of Life Science, Graduate School of Integral Arts and Science, Hiroshima University, Higashi-Hiroshima, Japan
| | - Yuri Nakamura
- Division of Life Science, Graduate School of Integral Arts and Science, Hiroshima University, Higashi-Hiroshima, Japan
| | - Takunori Satoh
- Division of Life Science, Graduate School of Integral Arts and Science, Hiroshima University, Higashi-Hiroshima, Japan
| | - Ziguang Liu
- Institute of Animal Husbandry, Heilongjiang Academy of Agricultural Sciences, Harbin, Heilongjiang, China
| | - Akiko K. Satoh
- Division of Life Science, Graduate School of Integral Arts and Science, Hiroshima University, Higashi-Hiroshima, Japan
- * E-mail:
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35
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Abstract
The Rab family of small GTPases play fundamental roles in the regulation of trafficking pathways between intracellular membranes in eukaryotic cells. In this short commentary we highlight a recent high-content screening study that investigates the roles of Rab proteins in retrograde trafficking from the Golgi complex to the endoplasmic reticulum, and we discuss how the findings of this work and other literature might influence our thoughts on how the architecture of the Golgi complex is regulated.
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Affiliation(s)
- George Galea
- a School of Biology and Environmental Science & UCD Conway Institute of Biomolecular and Biomedical Research; University College Dublin ; Dublin , Ireland
| | - Jeremy C Simpson
- a School of Biology and Environmental Science & UCD Conway Institute of Biomolecular and Biomedical Research; University College Dublin ; Dublin , Ireland
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36
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Aizawa M, Fukuda M. Small GTPase Rab2B and Its Specific Binding Protein Golgi-associated Rab2B Interactor-like 4 (GARI-L4) Regulate Golgi Morphology. J Biol Chem 2015. [PMID: 26209634 DOI: 10.1074/jbc.m115.669242] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Rab small GTPases are crucial regulators of the membrane traffic that maintains organelle identity and morphology. Several Rab isoforms are present in the Golgi, and it has been suggested that they regulate the compacted morphology of the Golgi in mammalian cells. However, the functional relationships among the Golgi-resident Rabs, e.g. whether they are functionally redundant or different, are poorly understood. In this study, we used specific siRNAs to perform genome-wide screening for human Rabs that are involved in Golgi morphology in HeLa-S3 cells. The results showed that knockdown of any one of the six Rab isoforms (Rab1A/1B/2A/2B/6B/8A) induced fragmentation of the Golgi in HeLa-S3 cells and that its phenotype was rescued by re-expression of their respective siRNA-resistant construct. We then performed systematic knockdown-rescue experiments in relation to each of the six Rabs. Interestingly, with the exception of the Rab8A knockdown, the Golgi fragmentation phenotype induced by knockdown of a single Rab isoform, e.g. Rab2B, was efficiently rescued by re-expression of its siRNA-resistant Rab alone, not by any of the other five Rabs, e.g. Rab2A, which is highly homologous to Rab2B, indicating that these Rab isoforms non-redundantly regulate Golgi morphology possibly through interaction with isoform-specific effector molecules. In addition, we identified Golgi-associated Rab2B interactor-like 4 (GARI-L4) as a novel Golgi-resident Rab2B-specific binding protein whose knockdown also induced fragmentation of the Golgi. Our findings suggest that the compacted Golgi morphology of mammalian cells is finely tuned by multiple sets of Rab (or Rab-effector complexes) that for the most part function independently.
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Affiliation(s)
- Megumi Aizawa
- From the Laboratory of Membrane Trafficking Mechanisms, Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Aobayama, Aoba-ku, Sendai, Miyagi 980-8578, Japan
| | - Mitsunori Fukuda
- From the Laboratory of Membrane Trafficking Mechanisms, Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Aobayama, Aoba-ku, Sendai, Miyagi 980-8578, Japan
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