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Ansari I, Singh AK, Kapoor A, Mukhopadhyay A. Unconventional role of Rab4 in the secretory pathway in Leishmania. Biochim Biophys Acta Mol Cell Res 2024; 1871:119687. [PMID: 38342312 DOI: 10.1016/j.bbamcr.2024.119687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 01/27/2024] [Accepted: 01/31/2024] [Indexed: 02/13/2024]
Abstract
Leishmania donovani is an auxotroph for heme. Parasite acquires heme by clathrin-mediated endocytosis of hemoglobin by specific receptor. However, the regulation of receptor recycling pathway is not known in Leishmania. Here, we have cloned, expressed and characterized the Rab4 homologue from L. donovani. We have found that LdRab4 localizes in both early endosomes and Golgi in L. donovani. To understand the role of LdRab4 in L. donovani, we have generated transgenic parasites overexpressing GFP-LdRab4:WT, GFP-LdRab4:Q67L, and GFP-LdRab4:S22N. Our results have shown that overexpression of GFP-LdRab4:Q67L or GFP-LdRab4:S22N does not alter the cell surface localization of hemoglobin receptor in L. donovani. Surprisingly, we have found that overexpression of GFP-LdRab4:S22N significantly blocks the transport of Ldgp63 to the cell surface whereas the trafficking of Ldgp63 is induced to the cell surface in GFP-LdRab4:WT and GFP-LdRab4:Q67L overexpressing parasites. Consequently, we have found significant inhibition of gp63 secretion by GFP-LdRab4:S22N overexpressing parasites whereas secretion of Ldgp63 is enhanced in GFP-LdRab4:WT and GFP-LdRab4:Q67L overexpressing parasites in comparison to untransfected control parasites. Moreover, we have found that survival of transgenic parasites overexpressing GFP-LdRab4:S22N is severely compromised in macrophages in comparison to GFP-LdRab4:WT and GFP-LdRab4:Q67L expressing parasites. These results demonstrated that LdRab4 unconventionally regulates the secretory pathway in L. donovani.
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Affiliation(s)
- Irshad Ansari
- Kusuma School of Biological Sciences, Indian Institute of Technology, Haus Khas, New Delhi 110016, India
| | - Amir Kumar Singh
- Kusuma School of Biological Sciences, Indian Institute of Technology, Haus Khas, New Delhi 110016, India
| | - Anjali Kapoor
- Kusuma School of Biological Sciences, Indian Institute of Technology, Haus Khas, New Delhi 110016, India
| | - Amitabha Mukhopadhyay
- Kusuma School of Biological Sciences, Indian Institute of Technology, Haus Khas, New Delhi 110016, India.
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2
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Wilson B, Flett C, Gemperle J, Lawless C, Hartshorn M, Hinde E, Harrison T, Chastney M, Taylor S, Allen J, Norman JC, Zacharchenko T, Caswell PT. Proximity labelling identifies pro-migratory endocytic recycling cargo and machinery of the Rab4 and Rab11 families. J Cell Sci 2023; 136:jcs260468. [PMID: 37232246 PMCID: PMC10323252 DOI: 10.1242/jcs.260468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 05/18/2023] [Indexed: 05/27/2023] Open
Abstract
Endocytic recycling controls the return of internalised cargoes to the plasma membrane to coordinate their positioning, availability and downstream signalling. The Rab4 and Rab11 small GTPase families regulate distinct recycling routes, broadly classified as fast recycling from early endosomes (Rab4) and slow recycling from perinuclear recycling endosomes (Rab11), and both routes handle a broad range of overlapping cargoes to regulate cell behaviour. We adopted a proximity labelling approach, BioID, to identify and compare the protein complexes recruited by Rab4a, Rab11a and Rab25 (a Rab11 family member implicated in cancer aggressiveness), revealing statistically robust protein-protein interaction networks of both new and well-characterised cargoes and trafficking machinery in migratory cancer cells. Gene ontological analysis of these interconnected networks revealed that these endocytic recycling pathways are intrinsically connected to cell motility and cell adhesion. Using a knock-sideways relocalisation approach, we were further able to confirm novel links between Rab11, Rab25 and the ESCPE-1 and retromer multiprotein sorting complexes, and identify new endocytic recycling machinery associated with Rab4, Rab11 and Rab25 that regulates cancer cell migration in the 3D matrix.
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Affiliation(s)
- Beverley Wilson
- Wellcome Trust Centre for Cell-Matrix Research, School of Biological Sciences, Faculty of Biology Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester, M13 9PT, UK
| | - Chloe Flett
- Wellcome Trust Centre for Cell-Matrix Research, School of Biological Sciences, Faculty of Biology Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester, M13 9PT, UK
| | - Jakub Gemperle
- Wellcome Trust Centre for Cell-Matrix Research, School of Biological Sciences, Faculty of Biology Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester, M13 9PT, UK
| | - Craig Lawless
- Wellcome Trust Centre for Cell-Matrix Research, School of Biological Sciences, Faculty of Biology Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester, M13 9PT, UK
| | - Matthew Hartshorn
- Wellcome Trust Centre for Cell-Matrix Research, School of Biological Sciences, Faculty of Biology Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester, M13 9PT, UK
| | - Eleanor Hinde
- Wellcome Trust Centre for Cell-Matrix Research, School of Biological Sciences, Faculty of Biology Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester, M13 9PT, UK
| | - Tess Harrison
- Wellcome Trust Centre for Cell-Matrix Research, School of Biological Sciences, Faculty of Biology Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester, M13 9PT, UK
| | - Megan Chastney
- Wellcome Trust Centre for Cell-Matrix Research, School of Biological Sciences, Faculty of Biology Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester, M13 9PT, UK
| | - Sarah Taylor
- Wellcome Trust Centre for Cell-Matrix Research, School of Biological Sciences, Faculty of Biology Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester, M13 9PT, UK
| | - Jennifer Allen
- Wellcome Trust Centre for Cell-Matrix Research, School of Biological Sciences, Faculty of Biology Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester, M13 9PT, UK
| | - Jim C. Norman
- Cancer Research UK Beatson Institute, Glasgow, G61 1BD, UK
- School of Cancer Sciences, University of Glasgow, Glasgow, G61 1QH, UK
| | - Thomas Zacharchenko
- Wellcome Trust Centre for Cell-Matrix Research, School of Biological Sciences, Faculty of Biology Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester, M13 9PT, UK
| | - Patrick T. Caswell
- Wellcome Trust Centre for Cell-Matrix Research, School of Biological Sciences, Faculty of Biology Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester, M13 9PT, UK
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3
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Xu R, Wan M, Shi X, Ma S, Zhang L, Yi P, Zhang R. A Rab10-ACAP1-Arf6 GTPases cascade modulates M4 muscarinic acetylcholine receptor trafficking and signaling. Cell Mol Life Sci 2023; 80:87. [PMID: 36917255 PMCID: PMC11072986 DOI: 10.1007/s00018-023-04722-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 02/06/2023] [Accepted: 02/08/2023] [Indexed: 03/16/2023]
Abstract
Membrane trafficking processes regulate the G protein-coupled receptor activity. The muscarinic acetylcholine receptors (mAChRs) are highly pursued drug targets for neurological diseases, but the cellular machineries that control the trafficking of these receptors remain largely elusive. Here, we revealed the role of the small GTPase Rab10 as a negative regulator for the post-activation trafficking of M4 mAChR and the underlying mechanism. We show that constitutively active Rab10 arrests the receptor within Rab5-positive early endosomes and significantly hinders the resensitization of M4-mediated Ca2+ signaling. Mechanistically, M4 binds to Rab10-GTP, which requires the motif 386RKKRQMAA393 (R386-A393) within the third intracellular loop. Moreover, Rab10-GTP inactivates Arf6 by recruiting the Arf6 GTPase-activating protein, ACAP1. Strikingly, deletion of the motif R386-A393 causes M4 to bypass the control by Rab10 and switch to the Rab4-facilitated fast recycling pathway, thus reusing the receptor. Therefore, Rab10 couples the cargo sorting and membrane trafficking regulation through cycle between GTP-bound and GDP-bound state. Our findings suggest a model that Rab10 binds to the M4 like a molecular brake and controls the receptor's transport through endosomes, thus modulating the signaling, and this regulation is specific among the mAChR subtypes.
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Affiliation(s)
- Rongmei Xu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Min Wan
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, USA
| | - Xuemeng Shi
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
- College of Life Science, Henan Agricultural University, Zhengzhou, Henan, China
| | - Shumin Ma
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Lina Zhang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Ping Yi
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China.
| | - Rongying Zhang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China.
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4
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Li Y, Wang W, Lim HY. Drosophila transmembrane protein 214 (dTMEM214) regulates midgut glucose uptake and systemic glucose homeostasis. Dev Biol 2023; 495:92-103. [PMID: 36657508 PMCID: PMC9905329 DOI: 10.1016/j.ydbio.2023.01.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 01/11/2023] [Accepted: 01/12/2023] [Indexed: 01/19/2023]
Abstract
The availability of glucose transporter in the small intestine critically determines the capacity for glucose uptake and consequently systemic glucose homeostasis. Hence a better understanding of the physiological regulation of intestinal glucose transporter is pertinent. However, the molecular mechanisms that regulate sodium-glucose linked transporter 1 (SGLT1), the primary glucose transporter in the small intestine, remain incompletely understood. Recently, the Drosophila SLC5A5 (dSLC5A5) has been found to exhibit properties consistent with a dietary glucose transporter in the Drosophila midgut, the equivalence of the mammalian small intestine. Hence, the fly midgut could serve as a suitable model system for the study of the in vivo molecular underpinnings of SGLT1 function. Here, we report the identification, through a genetic screen, of Drosophila transmembrane protein 214 (dTMEM214) that acts in the midgut enterocytes to regulate systemic glucose homeostasis and glucose uptake. We show that dTMEM214 resides in the apical membrane and cytoplasm of the midgut enterocytes, and that the proper subcellular distribution of dTMEM214 in the enterocytes is regulated by the Rab4 GTPase. As a corollary, Rab4 loss-of-function phenocopies dTMEM214 loss-of-function in the midgut as shown by a decrease in enterocyte glucose uptake and an alteration in systemic glucose homeostasis. We further show that dTMEM214 regulates the apical membrane localization of dSLC5A5 in the enterocytes, thereby revealing dTMEM214 as a molecular regulator of glucose transporter in the midgut.
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Affiliation(s)
- Yue Li
- Department of Physiology, University of Oklahoma Health Science Center, Oklahoma City, OK, USA
| | - Weidong Wang
- Department of Medicine, Section of Endocrinology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Hui-Ying Lim
- Department of Physiology, University of Oklahoma Health Science Center, Oklahoma City, OK, USA.
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5
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Nie J. UNC0321 inhibits high glucose induced apoptosis in HUVEC by targeting Rab4. Biomed Pharmacother 2020; 131:110662. [PMID: 32877824 DOI: 10.1016/j.biopha.2020.110662] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 08/07/2020] [Accepted: 08/20/2020] [Indexed: 01/03/2023] Open
Abstract
The vascular complications in heart, brain, kidney and retina are the most common chronic complications of diabetes mellitus (DM). At present, it has become a research hotspot to regulate the abnormal apoptosis of vascular endothelial cells for DM treatment. UNC0321 is a high affinity GPCRs inhibitor, and has potential practical value in chromatin remodeling. In this study, we treated HUVEC with UNC0321 in vitro, and found that UNC0321 inhibit the level of Cleaved-Caspase3 and Bax, thus inhibiting the apoptosis caused by high glucose. In addition, UNC0321 also promoted cell proliferation and migration by activating Akt / mTOR pathway. The transcriptome changes of HUVEC cells cultured with high glucose with or without the treatment of UNC0321 were analysis using sequencing. It was found that Rab4 expression was significantly inhibited after UNC0321 treatment. Subsequently, we overexpressed Rab4 in HUVEC cells cultured with high glucose, and found that overexpression of Rab4 promoted the apoptosis, and inhibited cell proliferation and migration. At the same time, after overexpression of Rab4 in HUVEC cells treated with UNC0321, the number of apoptosis was significantly increased, cell proliferation and migration were inhibited, and the activity of Akt / mTOR pathway decreased. These data suggested that overexpression of Rab4 effectively blocked the inhibition of apoptosis and the increase of cell proliferation induced by UNC0321. In conclusion, we found that UNC0321 inhibits the apoptosis of HUVEC cells caused by high glucose through inhibiting Rab4 expression, providing new potential drugs and targets for the treatment of diabetic vascular complications.
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Affiliation(s)
- Jieming Nie
- Department of Internal Medicine, The Third Affiliated Hospital of Guangzhou Medical University, PR China.
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6
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White JA, Krzystek TJ, Hoffmar-Glennon H, Thant C, Zimmerman K, Iacobucci G, Vail J, Thurston L, Rahman S, Gunawardena S. Excess Rab4 rescues synaptic and behavioral dysfunction caused by defective HTT-Rab4 axonal transport in Huntington's disease. Acta Neuropathol Commun 2020; 8:97. [PMID: 32611447 PMCID: PMC7331280 DOI: 10.1186/s40478-020-00964-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 06/11/2020] [Indexed: 12/13/2022] Open
Abstract
Huntington's disease (HD) is characterized by protein inclusions and loss of striatal neurons which result from expanded CAG repeats in the poly-glutamine (polyQ) region of the huntingtin (HTT) gene. Both polyQ expansion and loss of HTT have been shown to cause axonal transport defects. While studies show that HTT is important for vesicular transport within axons, the cargo that HTT transports to/from synapses remain elusive. Here, we show that HTT is present with a class of Rab4-containing vesicles within axons in vivo. Reduction of HTT perturbs the bi-directional motility of Rab4, causing axonal and synaptic accumulations. In-vivo dual-color imaging reveal that HTT and Rab4 move together on a unique putative vesicle that may also contain synaptotagmin, synaptobrevin, and Rab11. The moving HTT-Rab4 vesicle uses kinesin-1 and dynein motors for its bi-directional movement within axons, as well as the accessory protein HIP1 (HTT-interacting protein 1). Pathogenic HTT disrupts the motility of HTT-Rab4 and results in larval locomotion defects, aberrant synaptic morphology, and decreased lifespan, which are rescued by excess Rab4. Consistent with these observations, Rab4 motility is perturbed in iNeurons derived from human Huntington's Disease (HD) patients, likely due to disrupted associations between the polyQ-HTT-Rab4 vesicle complex, accessory proteins, and molecular motors. Together, our observations suggest the existence of a putative moving HTT-Rab4 vesicle, and that the axonal motility of this vesicle is disrupted in HD causing synaptic and behavioral dysfunction. These data highlight Rab4 as a potential novel therapeutic target that could be explored for early intervention prior to neuronal loss and behavioral defects observed in HD.
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Affiliation(s)
- Joseph A. White
- Department of Biological Sciences, The State University of New York at Buffalo, New York, 14260 USA
| | - Thomas J. Krzystek
- Department of Biological Sciences, The State University of New York at Buffalo, New York, 14260 USA
| | - Hayley Hoffmar-Glennon
- Department of Biological Sciences, The State University of New York at Buffalo, New York, 14260 USA
| | - Claire Thant
- Department of Biological Sciences, The State University of New York at Buffalo, New York, 14260 USA
| | - Katherine Zimmerman
- Department of Biological Sciences, The State University of New York at Buffalo, New York, 14260 USA
| | - Gary Iacobucci
- Department of Biological Sciences, The State University of New York at Buffalo, New York, 14260 USA
| | - Julia Vail
- Department of Biological Engineering, Cornell University, Ithaca, NY USA
| | - Layne Thurston
- Department of Biological Sciences, The State University of New York at Buffalo, New York, 14260 USA
| | - Saad Rahman
- Department of Biological Sciences, The State University of New York at Buffalo, New York, 14260 USA
| | - Shermali Gunawardena
- Department of Biological Sciences, The State University of New York at Buffalo, New York, 14260 USA
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Kong L, Xiao F, Wang L, Li M, Wang D, Feng Z, Huang L, Wei Y, Li H, Liu F, Kang Y, Liao X, Zhang W. Intermedin promotes vessel fusion by inducing VE-cadherin accumulation at potential fusion sites and to achieve a dynamic balance between VE-cadherin-complex dissociation/reconstitution. MedComm (Beijing) 2020; 1:84-102. [PMID: 34766111 PMCID: PMC8489673 DOI: 10.1002/mco2.9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 05/05/2020] [Accepted: 05/08/2020] [Indexed: 02/05/2023] Open
Abstract
To create a closed vascular system, angiogenic sprouts must meet and connect in a process called vessel fusion, which is a prerequisite for establishment of proper blood flow in nascent vessels. However, the molecular machinery underlying this process remains largely unknown. Herein, we report that intermedin (IMD), a calcitonin family member, promotes vessel fusion by inducing endothelial cells (ECs) to enter a "ready-to-anchor" state. IMD promotes vascular endothelial cadherin (VEC) accumulation at the potential fusion site to facilitate anchoring of approaching vessels to each other. Simultaneously, IMD fine-tunes VEC activity to achieve a dynamic balance between VEC complex dissociation and reconstitution in order to widen the anastomotic point. IMD induces persistent VEC phosphorylation. Internalized phospho-VEC preferentially binds to Rab4 and Rab11, which facilitate VEC vesicle recycling back to the cell-cell contact for reconstruction of the VEC complex. This novel mechanism may explain how neovessels contact and fuse to adjacent vessels to create a closed vascular system.
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Affiliation(s)
- Lingmiao Kong
- Department of Critical Care Medicine State Key Laboratory of Biotherapy and Cancer Center West China Hospital Sichuan University and Collaborative Innovation Center of Biotherapy Chengdu China
| | - Fei Xiao
- Department of Intensive Care Unit of Gynecology and Obstetrics West China Second University Hospital Sichuan University Chengdu China
| | - Lijun Wang
- Department of Critical Care Medicine State Key Laboratory of Biotherapy and Cancer Center West China Hospital Sichuan University and Collaborative Innovation Center of Biotherapy Chengdu China
| | - Min Li
- Department of Critical Care Medicine State Key Laboratory of Biotherapy and Cancer Center West China Hospital Sichuan University and Collaborative Innovation Center of Biotherapy Chengdu China
| | - Denian Wang
- Department of Critical Care Medicine State Key Laboratory of Biotherapy and Cancer Center West China Hospital Sichuan University and Collaborative Innovation Center of Biotherapy Chengdu China
| | - Zhongxue Feng
- Department of Critical Care Medicine State Key Laboratory of Biotherapy and Cancer Center West China Hospital Sichuan University and Collaborative Innovation Center of Biotherapy Chengdu China
| | - Luping Huang
- Department of Critical Care Medicine State Key Laboratory of Biotherapy and Cancer Center West China Hospital Sichuan University and Collaborative Innovation Center of Biotherapy Chengdu China
| | - Yong'gang Wei
- Department of Liver Surgery West China Hospital Sichuan University Chengdu China
| | - Hongyu Li
- Liver Transplantation Center Beijing Friendship Hospital Capital Medical University Chengdu China
| | - Fei Liu
- Department of Liver Surgery West China Hospital Sichuan University Chengdu China
| | - Yan Kang
- Department of Critical Care Medicine West China Hospital Sichuan University Chengdu China
| | - Xuelian Liao
- Department of Critical Care Medicine West China Hospital Sichuan University Chengdu China
| | - Wei Zhang
- Department of Critical Care Medicine State Key Laboratory of Biotherapy and Cancer Center West China Hospital Sichuan University and Collaborative Innovation Center of Biotherapy Chengdu China
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Wang XL, Lu T, Sun X, Lee HC. Membrane trafficking of large conductance Ca 2+- and voltage-activated K + (BK) channels is regulated by Rab4 GTPase. Biochim Biophys Acta Mol Cell Res 2020; 1867:118646. [PMID: 31926210 DOI: 10.1016/j.bbamcr.2020.118646] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 12/26/2019] [Accepted: 01/06/2020] [Indexed: 12/28/2022]
Abstract
The large conductance voltage- and Ca2+-activated K+ (BK) channel is a major ionic determinant of vascular tone, vasodilation, and blood pressure. The activity of BK channels is regulated in part by membrane presentation. Rab GTPase (Rab) regulates important cellular processes, including ion channel membrane trafficking. We hypothesize that Rab4a participates in the regulation of BK channel α-subunit (BK-α) membrane trafficking. We found that vascular BK-α interacts physically with Rab4a. Co-expression of dominant-negative Rab4a reduced BK-α surface expression, whereas that of constitutively-active Rab4a augmented BK-α surface presentation. These novel findings suggest that vascular BK channel membrane expression is regulated by Rab4a through channel membrane trafficking.
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Affiliation(s)
- Xiao-Li Wang
- Department of Cardiovascular Diseases, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
| | - Tong Lu
- Department of Cardiovascular Diseases, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
| | - Xiaojing Sun
- Department of Cardiovascular Diseases, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
| | - Hon-Chi Lee
- Department of Cardiovascular Diseases, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
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Prabhu VV, Nguyen TB, Cui Y, Oh YE, Lee KH, Bagalkot TR, Chung YC. Effects of social defeat stress on dopamine D2 receptor isoforms and proteins involved in intracellular trafficking. Behav Brain Funct 2018; 14:16. [PMID: 30296947 DOI: 10.1186/s12993-018-0148-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 09/27/2018] [Indexed: 12/15/2022] Open
Abstract
Background Chronic social defeat stress induces depression and anxiety-like behaviors in rodents and also responsible for differentiating defeated animals into stress susceptible and resilient groups. The present study investigated the effects of social defeat stress on a variety of behavioral parameters like social behavior, spatial learning and memory and anxiety like behaviors. Additionally, the levels of various dopaminergic markers, including the long and short form of the D2 receptor, and total and phosphorylated dopamine and cyclic adenosine 3′,5′-monophosphate regulated phosphoprotein-32, and proteins involved in intracellular trafficking were assessed in several key brain regions in young adult mice. Methods Mouse model of chronic social defeat was established by resident-intruder paradigm, and to evaluate the effect of chronic social defeat, mice were subjected to behavioral tests like spontaneous locomotor activity, elevated plus maze (EPM), social interaction and Morris water maze tests. Results Mice were divided into susceptible and unsusceptible groups after 10 days of social defeat stress. The susceptible group exhibited greater decreases in time spent in the open and closed arms compared to the control group on the EPM. In the social interaction test, the susceptible group showed greater increases in submissive and neutral behaviors and greater decreases in social behaviors relative to baseline compared to the control group. Furthermore, increased expression of D2L, D2S, Rab4, and G protein-coupled receptor associated sorting protein-1 was observed in the amygdala of the susceptible group compared to the control group. Conclusion These findings suggest that social defeat stress induce anxiety-like and altered social interacting behaviors, and changes in dopaminergic markers and intracellular trafficking-related proteins. Electronic supplementary material The online version of this article (10.1186/s12993-018-0148-5) contains supplementary material, which is available to authorized users.
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10
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Augustin H, McGourty K, Allen MJ, Adcott J, Wong CT, Boucrot E, Partridge L. Impact of insulin signaling and proteasomal activity on physiological output of a neuronal circuit in aging Drosophila melanogaster. Neurobiol Aging 2018; 66:149-157. [PMID: 29579685 PMCID: PMC5933513 DOI: 10.1016/j.neurobiolaging.2018.02.027] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 01/26/2018] [Accepted: 02/27/2018] [Indexed: 12/11/2022]
Abstract
The insulin family of growth factors plays an important role in development and function of the nervous system. Reduced insulin and insulin-growth-factor signaling (IIS), however, can improve symptoms of neurodegenerative diseases in laboratory model organisms and protect against age-associated decline in neuronal function. Recently, we showed that chronic, moderately lowered IIS rescues age-related decline in neurotransmission through the Drosophila giant fiber escape response circuit. Here, we expand our initial findings by demonstrating that reduced functional output in the giant fiber system of aging flies can be prevented by increasing proteasomal activity within the circuit. Manipulations of IIS in neurons can also affect longevity, underscoring the relevance of the nervous system for aging.
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Affiliation(s)
- Hrvoje Augustin
- Max Planck Institute for Biology of Ageing, Köln, Germany; Institute of Healthy Ageing, and GEE, University College London, London, UK
| | - Kieran McGourty
- Department of Structural and Molecular Biology, London, UK; The Bernal Institute, University of Limerick, Limerick, Ireland
| | - Marcus J Allen
- School of Biosciences, University of Kent, Canterbury, Kent, UK
| | - Jennifer Adcott
- Institute of Healthy Ageing, and GEE, University College London, London, UK
| | - Chi Tung Wong
- Institute of Healthy Ageing, and GEE, University College London, London, UK
| | | | - Linda Partridge
- Max Planck Institute for Biology of Ageing, Köln, Germany; Institute of Healthy Ageing, and GEE, University College London, London, UK.
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11
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Dey S, Banker G, Ray K. Anterograde Transport of Rab4-Associated Vesicles Regulates Synapse Organization in Drosophila. Cell Rep 2017; 18:2452-2463. [PMID: 28273459 DOI: 10.1016/j.celrep.2017.02.034] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 12/19/2016] [Accepted: 02/09/2017] [Indexed: 11/29/2022] Open
Abstract
Local endosomal recycling at synapses is essential to maintain neurotransmission. Rab4GTPase, found on sorting endosomes, is proposed to balance the flow of vesicles among endocytic, recycling, and degradative pathways in the presynaptic compartment. Here, we report that Rab4-associated vesicles move bidirectionally in Drosophila axons but with an anterograde bias, resulting in their moderate enrichment at the synaptic region of the larval ventral ganglion. Results from FK506 binding protein (FKBP) and FKBP-Rapamycin binding domain (FRB) conjugation assays in rat embryonic fibroblasts together with genetic analyses in Drosophila indicate that an association with Kinesin-2 (mediated by the tail domain of Kinesin-2α/KIF3A/KLP64D subunit) moves Rab4-associated vesicles toward the synapse. Reduction in the anterograde traffic of Rab4 causes an expansion of the volume of the synapse-bearing region in the ventral ganglion and increases the motility of Drosophila larvae. These results suggest that Rab4-dependent vesicular traffic toward the synapse plays a vital role in maintaining synaptic balance in this neuronal network.
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Affiliation(s)
- Swagata Dey
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India.
| | - Gary Banker
- Jungers Center for Neurosciences Research, Oregon Health and Science University, Portland, OR 97239, USA
| | - Krishanu Ray
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India.
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12
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Jackson TC, Kotermanski SE, Kochanek PM. Whole-transcriptome microarray analysis reveals regulation of Rab4 by RBM5 in neurons. Neuroscience 2017; 361:93-107. [PMID: 28818525 PMCID: PMC5605467 DOI: 10.1016/j.neuroscience.2017.08.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2017] [Revised: 08/04/2017] [Accepted: 08/06/2017] [Indexed: 12/27/2022]
Abstract
RNA binding motif 5 (RBM5) is a nuclear protein that modulates gene transcription and mRNA splicing in cancer cells. The brain is among the highest RBM5-expressing organ in the body but its mRNA target(s) or functions in the CNS have not been elucidated. Here we knocked down (KO) RBM5 in primary rat cortical neurons and analyzed total RNA extracts by gene microarray vs. neurons transduced with lentivirus to deliver control (non-targeting) shRNA. The mRNA levels of Sec23A (involved in ER-Golgi transport) and the small GTPase Rab4a (involved in endocytosis/protein trafficking) were increased in RBM5 KO neurons relative to controls. At the protein level, only Rab4a was significantly increased in RBM5 KO extracts. Also, elevated Rab4a levels in KO neurons were associated with decreased membrane levels of oligomeric serotonin transporters (SERT). Finally, RBM5 KO was associated with increased uptake of membrane-derived monomeric SERT. SIGNIFICANCE Rab4a is involved in the regulation of endocytosis and protein trafficking in cells. In the CNS it regulates diverse neurobiological functions including (but not limited to) trafficking of transmembrane proteins involved in neurotransmission (e.g. SERT), maintaining dendritic spine size, promoting axonal growth, and modulating cognition. Our findings suggest that RBM5 regulates Rab4a in rat neurons.
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Affiliation(s)
- Travis C Jackson
- University of Pittsburgh School of Medicine, Safar Center for Resuscitation Research, Children's Hospital of Pittsburgh of UPMC, John G. Rangos Research Center - 6th Floor, 4401 Penn Avenue, Pittsburgh, PA 15224, United States; University of Pittsburgh School of Medicine, Department of Critical Care Medicine, Scaife Hall, 3550 Terrace Street, United States.
| | - Shawn E Kotermanski
- University of Pittsburgh School of Medicine, Department of Pharmacology and Chemical Biology, Bridgeside Point Building 1, 100 Technology Drive, United States
| | - Patrick M Kochanek
- University of Pittsburgh School of Medicine, Safar Center for Resuscitation Research, Children's Hospital of Pittsburgh of UPMC, John G. Rangos Research Center - 6th Floor, 4401 Penn Avenue, Pittsburgh, PA 15224, United States; University of Pittsburgh School of Medicine, Department of Critical Care Medicine, Scaife Hall, 3550 Terrace Street, United States
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13
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Abstract
Synaptic connections in the brain are continuously weakened or strengthened in response to changes in neuronal activity. This process, known as synaptic plasticity, is the cellular basis for learning and memory, and is thought to be altered in several neuronal disorders. An important aspect of synaptic plasticity is the tightly controlled trafficking and synaptic targeting of the AMPA-type glutamate receptors, which are the major mediators of fast excitatory transmission in the brain. This review addresses the role of Rab GTPases in AMPA receptor trafficking in neurons under basal conditions and during activity-induced synaptic plasticity, especially during long-term potentiation (LTP) and long-term depression (LTD). We highlight the importance of the tight spatio-temporal control of Rab activity and suggest that this is critical for proper neuronal functions. We also discuss how abnormal AMPA receptor trafficking and malfunctioning of Rabs can lead to neurologic disorders or memory problems.
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Affiliation(s)
- Angelika Hausser
- Institute of Cell Biology and Immunology, University of Stuttgart , Stuttgart , Germany.,Stuttgart Research Center Systems Biology, University of Stuttgart , Stuttgart , Germany
| | - Katalin Schlett
- Department of Physiology and Neurobiology, Eötvös Loránd University , Budapest , Hungary.,MTA-ELTE NAP B Neuronal Cell Biology Research Group, Eötvös Loránd University , Budapest , Hungary
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14
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Al-Zoairy R, Pedrini MT, Khan MI, Engl J, Tschoner A, Ebenbichler C, Gstraunthaler G, Salzmann K, Bakry R, Niederwanger A. Serotonin improves glucose metabolism by Serotonylation of the small GTPase Rab4 in L6 skeletal muscle cells. Diabetol Metab Syndr 2017; 9:1. [PMID: 28053672 PMCID: PMC5209910 DOI: 10.1186/s13098-016-0201-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 12/10/2016] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Serotonin (5-HT) improves insulin sensitivity and glucose metabolism, however, the underlying molecular mechanism has remained elusive. Previous studies suggest that 5-HT can activate intracellular small GTPases directly by covalent binding, a process termed serotonylation. Activated small GTPases have been associated with increased GLUT4 translocation to the cell membrane. Therefore, we investigated whether serotonylation of small GTPases may be involved in improving Insulin sensitivity and glucose metabolism. METHODS Using fully differentiated L6 rat skeletal muscle cells, we studied the effect of 5-HT in the absence or presence of insulin on glycogen synthesis, glucose uptake and GLUT4 translocation. To prove our L6 model we additionally performed preliminary experiments in C2C12 murine skeletal muscle cells. RESULTS Incubation with 5-HT led to an increase in deoxyglucose uptake in a concentration-dependent fashion. Accordingly, GLUT4 translocation to the cell membrane and glycogen content were increased. These effects of 5-HT on Glucose metabolism could be augmented by co-incubation with insulin and blunted by co incubation of 5-HT with monodansylcadaverine, an inhibitor of protein serotonylation. In accordance with this observation, incubation with 5-HT resulted in serotonylation of a protein with a molecular weight of approximately 25 kDa. We identified this protein as the small GTPase Rab4, the activity of which has been shown to be stimulated by both insulin signalling and serotonylation. CONCLUSION Our data suggest that 5-HT elicits its beneficial effects on Glucose metabolism through serotonylation of Rab4, which likely represents the converging point between the insulin and the 5-HT signalling cascades.
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Affiliation(s)
- Ramona Al-Zoairy
- Department of Internal Medicine I, Medical University of Innsbruck, Innsbruck, Austria
| | - Michael T. Pedrini
- Department of Internal Medicine I, Medical University of Innsbruck, Innsbruck, Austria
| | - Mohammad Imran Khan
- Department of Internal Medicine I, Medical University of Innsbruck, Innsbruck, Austria
| | - Julia Engl
- Department of Internal Medicine I, Medical University of Innsbruck, Innsbruck, Austria
| | - Alexander Tschoner
- Department of Internal Medicine I, Medical University of Innsbruck, Innsbruck, Austria
| | - Christoph Ebenbichler
- Department of Internal Medicine I, Medical University of Innsbruck, Innsbruck, Austria
| | | | - Karin Salzmann
- Department of Internal Medicine I, Medical University of Innsbruck, Innsbruck, Austria
| | - Rania Bakry
- Institute of Analytical Chemistry and Radiochemistry, Leopold-Franzens University Innsbruck, Innsbruck, Austria
| | - Andreas Niederwanger
- Department of Internal Medicine I, Medical University of Innsbruck, Innsbruck, Austria
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15
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Abstract
The secretion of immune-mediators is a critical step in the host innate immune response to pathogen invasion, and Rab GTPases have an important role in the regulation of this process. Rab4/Rab11 recycling endosomes are involved in the sorting of immune-mediators into specialist Rab11 vesicles that can traffic this cargo to the plasma membrane; however, how this sequential delivery process is regulated has yet to be fully defined. Here, we report that Drosophila Pkaap, an orthologue of the human dual-specific A-kinase-anchoring protein 2 or D-AKAP2 (also called AKAP10), appeared to have a nucleotide-dependent localisation to Rab4 and Rab11 endosomes. RNAi silencing of pkaap altered Rab4/Rab11 recycling endosome morphology, suggesting that Pkaap functions in cargo sorting and delivery in the secretory pathway. The depletion of pkaap also had a direct effect on Rab11 vesicle exocytosis and the secretion of the antimicrobial peptide Drosomycin at the plasma membrane. We propose that Pkaap has a dual role in antimicrobial peptide traffic and exocytosis, making it an essential component for the secretion of inflammatory mediators and the defence of the host against pathogens.
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Affiliation(s)
- Alexandra Sorvina
- Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia 5001, Australia
| | - Tetyana Shandala
- Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia 5001, Australia
| | - Douglas A Brooks
- Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia 5001, Australia
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16
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Chamberland JP, Antonow LT, Dias Santos M, Ritter B. NECAP2 controls clathrin coat recruitment to early endosomes for fast endocytic recycling. J Cell Sci 2016; 129:2625-37. [PMID: 27206861 DOI: 10.1242/jcs.173708] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 05/19/2016] [Indexed: 01/04/2023] Open
Abstract
Endocytic recycling returns receptors to the plasma membrane following internalization and is essential to maintain receptor levels on the cell surface, re-sensitize cells to extracellular ligands and for continued nutrient uptake. Yet, the protein machineries and mechanisms that drive endocytic recycling remain ill-defined. Here, we establish that NECAP2 regulates the endocytic recycling of EGFR and transferrin receptor. Our analysis of the recycling dynamics revealed that NECAP2 functions in the fast recycling pathway that directly returns cargo from early endosomes to the cell surface. In contrast, NECAP2 does not regulate the clathrin-mediated endocytosis of these cargos, the degradation of EGFR or the recycling of transferrin along the slow, Rab11-dependent recycling pathway. We show that protein knockdown of NECAP2 leads to enlarged early endosomes and causes the loss of the clathrin adapter AP-1 from the organelle. Through structure-function analysis, we define the protein-binding interfaces in NECAP2 that are crucial for AP-1 recruitment to early endosomes. Together, our data identify NECAP2 as a pathway-specific regulator of clathrin coat formation on early endosomes for fast endocytic recycling.
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Affiliation(s)
- John P Chamberland
- Boston University School of Medicine, Biochemistry Department, Boston, MA 02118, USA
| | - Lauren T Antonow
- Boston University School of Medicine, Biochemistry Department, Boston, MA 02118, USA
| | - Michel Dias Santos
- Boston University School of Medicine, Biochemistry Department, Boston, MA 02118, USA
| | - Brigitte Ritter
- Boston University School of Medicine, Biochemistry Department, Boston, MA 02118, USA
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17
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Schafer JC, McRae RE, Manning EH, Lapierre LA, Goldenring JR. Rab11-FIP1A regulates early trafficking into the recycling endosomes. Exp Cell Res 2016; 340:259-73. [PMID: 26790954 DOI: 10.1016/j.yexcr.2016.01.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2015] [Revised: 12/19/2015] [Accepted: 01/10/2016] [Indexed: 12/31/2022]
Abstract
The Rab11 family of small GTPases, along with the Rab11-family interacting proteins (Rab11-FIPs), are critical regulators of intracellular vesicle trafficking and recycling. We have identified a point mutation of Threonine-197 site to an Alanine in Rab11-FIP1A, which causes a dramatic dominant negative phenotype when expressed in HeLa cells. The normally perinuclear distribution of GFP-Rab11-FIP1A was condensed into a membranous cisternum with almost no GFP-Rab11-FIP1A(T197A) remaining outside of this central locus. Also, this condensed GFP-FIP1A(T197A) altered the distribution of proteins in the Rab11a recycling pathway including endogenous Rab11a, Rab11-FIP1C, and transferrin receptor (CD71). Furthermore, this condensed GFP-FIP1A(T197A)-containing structure exhibited little movement in live HeLa cells. Expression of GFP-FIP1A(T197A) caused a strong blockade of transferrin recycling. Treatment of cells expressing GFP-FIP1A(T197A) with nocodazole did not disperse the Rab11a-containing recycling system. We also found that Rab5 and EEA1 were accumulated in membranes by GFP-Rab11-FIP1A but Rab4 was unaffected, suggesting that a direct pathway may exist from early endosomes into the Rab11a-containing recycling system. Our study of a potent inhibitory trafficking mutation in Rab11-FIP1A shows that Rab11-FIP1A associates with and regulates trafficking at an early step in the process of membrane recycling.
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Affiliation(s)
- Jenny C Schafer
- Departments of Surgery, Nashville, TN, USA; Epithelial Biology Center, Nashville, TN, USA
| | - Rebecca E McRae
- Departments of Surgery, Nashville, TN, USA; Cell & Developmental Biology, Nashville, TN, USA; Epithelial Biology Center, Nashville, TN, USA
| | - Elizabeth H Manning
- Departments of Surgery, Nashville, TN, USA; Epithelial Biology Center, Nashville, TN, USA
| | - Lynne A Lapierre
- Departments of Surgery, Nashville, TN, USA; Epithelial Biology Center, Nashville, TN, USA
| | - James R Goldenring
- Departments of Surgery, Nashville, TN, USA; Cell & Developmental Biology, Nashville, TN, USA; Epithelial Biology Center, Nashville, TN, USA; Vanderbilt University School of Medicine and the Nashville VA Medical Center, Nashville, TN, USA.
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18
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de Madrid BH, Greenberg L, Hatini V. RhoGAP68F controls transport of adhesion proteins in Rab4 endosomes to modulate epithelial morphogenesis of Drosophila leg discs. Dev Biol 2015; 399:283-95. [PMID: 25617722 PMCID: PMC4352398 DOI: 10.1016/j.ydbio.2015.01.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 12/15/2014] [Accepted: 01/10/2015] [Indexed: 02/06/2023]
Abstract
Elongation and invagination of epithelial tissues are fundamental developmental processes that contribute to the morphogenesis of embryonic and adult structures and are dependent on coordinated remodeling of cell-cell contacts. The morphogenesis of Drosophila leg imaginal discs depends on extensive remodeling of cell contacts and thus provides a useful system with which to investigate the underlying mechanisms. The small Rho GTPase regulator RhoGAP68F has been previously implicated in leg morphogenesis. It consists of on an N-terminal Sec14 domain and a C-terminal GAP domain. Here we examined the molecular function and role of RhoGAP68F in epithelial remodeling. We find that depletion of RhoGAP68F impairs epithelial remodeling from a pseudostratified to simple, while overexpression of RhoGAP68F causes tears of lateral cell-cell contacts and thus impairs epithelial integrity. We show that the RhoGAP68F protein localizes to Rab4 recycling endosomes and forms a complex with the Rab4 protein. The Sec14 domain is sufficient for localizing to Rab4 endosomes, while the activity of the GAP domain is dispensable. RhoGAP68F, in turn, inhibits the scission and movement of Rab4 endosomes involved in transport the adhesion proteins Fasciclin3 and E-cadherin back to cell-cell contacts. Expression of RhoGAP68F is upregulated during prepupal development suggesting that RhoGAP68F decreases the transport of key adhesion proteins to the cell surface during this developmental stage to decrease the strength of adhesive cell-cell contacts and thereby facilitate epithelial remodeling and leg morphogenesis.
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Affiliation(s)
- Beatriz Hernandez de Madrid
- Department of Developmental, Molecular and Chemical Biology, Program in Cell, Molecular and Developmental Biology, Program in Genetics, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, 150 Harrison Avenue, Boston, MA 02111, USA
| | - Lina Greenberg
- Department of Developmental, Molecular and Chemical Biology, Program in Cell, Molecular and Developmental Biology, Program in Genetics, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, 150 Harrison Avenue, Boston, MA 02111, USA
| | - Victor Hatini
- Department of Developmental, Molecular and Chemical Biology, Program in Cell, Molecular and Developmental Biology, Program in Genetics, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, 150 Harrison Avenue, Boston, MA 02111, USA.
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19
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Park SW, Schonhoff CM, Webster CRL, Anwer MS. Rab11, but not Rab4, facilitates cyclic AMP- and tauroursodeoxycholate-induced MRP2 translocation to the plasma membrane. Am J Physiol Gastrointest Liver Physiol 2014; 307:G863-70. [PMID: 25190474 PMCID: PMC4200318 DOI: 10.1152/ajpgi.00457.2013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Rab proteins (Ras homologous for brain) play an important role in vesicle trafficking. Rab4 and Rab11 are involved in vesicular trafficking to the plasma membrane from early endosomes and recycling endosomes, respectively. Tauroursodeoxycholate (TUDC) and cAMP increase bile formation, in part, by increasing plasma membrane localization of multidrug resistance-associated protein 2 (MRP2). The goal of the present study was to determine the role of these Rab proteins in the trafficking of MRP2 by testing the hypothesis that Rab11 and/or Rab4 facilitate cAMP- and TUDC-induced MRP2 translocation to the plasma membrane. Studies were conducted in HuH-NTCP cells (HuH7 cells stably transfected with human NTCP), which constitutively express MRP2. HuH-NTCP cells were transfected with Rab11-WT and GDP-locked dominant inactive Rab11-GDP or with Rab4-GDP to study the role of Rab11 and Rab4. A biotinylation method and a GTP overlay assay were used to determine plasma membrane MRP2 and activation of Rab proteins (Rab11 and Rab4), respectively. Cyclic AMP and TUDC increased plasma membrane MRP2 and stimulated Rab11 activity. Plasma membrane translocation of MRP2 by cAMP and TUDC was increased and inhibited in cells transfected with Rab11-WT and Rab11-GDP, respectively. Cyclic AMP (previous study) and TUDC increased Rab4 activity. However, cAMP- and TUDC-induced increases in MRP2 were not inhibited by Rab4-GDP. Taken together, these results suggest that Rab11 is involved in cAMP- and TUDC-induced MRP2 translocation to the plasma membrane.
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Affiliation(s)
- Se Won Park
- Department of Biomedical Sciences, Cummings School of Veterinary Medicine at Tufts University, North Grafton, Massachusetts; and
| | - Christopher M Schonhoff
- Department of Biomedical Sciences, Cummings School of Veterinary Medicine at Tufts University, North Grafton, Massachusetts; and
| | - Cynthia R L Webster
- Department of Clinical Sciences, Cummings School of Veterinary Medicine at Tufts University, North Grafton, Massachusetts
| | - M Sawkat Anwer
- Department of Biomedical Sciences, Cummings School of Veterinary Medicine at Tufts University, North Grafton, Massachusetts; and
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20
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Abstract
In Drosophila, anti-microbial peptides are activated and secreted in response to microbial challenge, but the intracellular route of anti-microbial peptide trafficking and the regulatory mechanism controlling their secretion are yet to be fully characterized. We have demonstrated that in Drosophila immune response cells (i.e., fat body cells and hemocytes) the anti-microbial peptide Drosomycin is localized within Rab4 and Rab11 intracellular vesicles. Moreover, both of these small GTPases were required for the delivery of this Drosomycin cargo to the plasma membrane. At the plasma membrane, exocytosis and Drosomycin secretion depend on the SNARE protein Syntaxin1A. Thus, the depletion of Syntaxin1A impaired the release of this antimicrobial peptide, and resulted in the accumulation of Drosomycin and Rab11 carrier vesicles near the plasma membrane. Intriguingly, a similar phenotype was generated by the loss of the adaptor protein 14-3-3ε; there was accumulation of Rab11 vesicles and Drosomycin containing vesicles near the plasma membrane, and a concomitant increase in the susceptibility of 14-3-3ε mutant Drosophila to acute bacterial infection. This suggested that 14-3-3ε, possibly via interaction with Syntaxin1A, is required to promote exocytosis of immune-mediators, thereby regulating innate immune secretion and organism survival under conditions of immune stress.
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21
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Hoogenraad CC, van der Sluijs P. GRASP-1 regulates endocytic receptor recycling and synaptic plasticity. Commun Integr Biol 2011; 3:433-5. [PMID: 21057633 DOI: 10.4161/cib.3.5.12209] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Accepted: 04/28/2010] [Indexed: 11/19/2022] Open
Abstract
Remodeling of synapses is a fundamental mechanism for information storage and processing in the brain. Previous studies showed that the endosomal pathway plays a central role in synapse formation and plasticity. A popular model holds that recycling endosomes in dendrites provide the local intracellular pool of postsynaptic receptors for long-term potentiation (LTP), a widely studied cellular model for learning and memory formation. However, we are far from a complete understanding how endocytic receptor sorting and recycling is organized and coordinated in dendrites. Especially, the molecular mechanisms that couple specific endosomal trafficking routes during LTP are poorly understood. In a recent paper we discovered that the coiled-coil protein GRIP-associated protein-1 (GRASP-1) is a neuron-specific effector of the small GTPase Rab4 and key component of AMPA receptor recycling machinery in dendrites.1 GRASP-1 is essential for maintenance of spine morphology and important for LTP. GRASP-1 connects Rab4 and Rab11 recycling endosomal domains through the interaction with target (t)-SNARE syntaxin 13, which constitutes a new principle for regulating endosomal recycling. Here, we summarize our recently reported observations and further discuss their possible implications.
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