1
|
Li FL, Guan KL. The Arf family GTPases: Regulation of vesicle biogenesis and beyond. Bioessays 2023; 45:e2200214. [PMID: 36998106 PMCID: PMC10282109 DOI: 10.1002/bies.202200214] [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: 11/05/2022] [Revised: 03/16/2023] [Accepted: 03/17/2023] [Indexed: 04/01/2023]
Abstract
The Arf family proteins are best known for their roles in the vesicle biogenesis. However, they also play fundamental roles in a wide range of cellular regulation besides vesicular trafficking, such as modulation of lipid metabolic enzymes, cytoskeleton remodeling, ciliogenesis, lysosomal, and mitochondrial morphology and functions. Growing studies continue to expand the downstream effector landscape of Arf proteins, especially for the less-studied members, revealing new biological functions, such as amino acid sensing. Experiments with cutting-edge technologies and in vivo functional studies in the last decade help to provide a more comprehensive view of Arf family functions. In this review, we summarize the cellular functions that are regulated by at least two different Arf members with an emphasis on those beyond vesicle biogenesis.
Collapse
Affiliation(s)
- Fu-Long Li
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Kun-Liang Guan
- Department of Pharmacology and Moores Cancer Center, University of California San Diego, La Jolla, CA, USA
| |
Collapse
|
2
|
Chidipi B, Chang M, Abou-Assali O, Reiser M, Tian Z, Allen-Gipson D, Noujaim SF. The Arf6/PIP5K pathway activates IKACh in cigarette smoke mediated atrial fibrillation. Cell Signal 2022; 100:110475. [PMID: 36150420 DOI: 10.1016/j.cellsig.2022.110475] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 08/29/2022] [Accepted: 09/16/2022] [Indexed: 11/29/2022]
Abstract
Cigarette smoking (CS) is a major cause of cardiovascular diseases. Smokers are at a significantly higher risk for developing atrial fibrillation (AF), a dangerous and abnormal heart rhythm. In the US, 15.5% of adults are current smokers, and it is becoming clear that CS is an independent risk factor for AF, but a detailed mechanistic understanding of how CS contributes to the molecular patho-electrophysiology of AF remains elusive. We investigated if CS related AF is in part mediated through a mechanism that depends on the cardiac acetylcholine activated inward rectifier potassium current (IKACh). We tested the hypothesis that CS increases IKACh via phosphatidylinositol 4-phosphate 5-kinase alpha (PIP5K) and ADP ribosylation factor 6 (Arf6) signaling, leading to AF perpetuation. In vivo inducibility of AF was assessed in mice exposed to CS for 8 weeks. AF duration was increased in CS exposed mice, and TertiapinQ, an IKACh blocker prevented AF development in CS exposed mice. In HEK293 cells stably transfected with Kir3.1 and Kir3.4, the molecular correlates of IKACh, CS exposure increased the expression of the Kir3.1 and Kir3.4 proteins at the cell surface, activated Arf6 and increased the IKACh current. Inhibition of PIP5K, or of Kir3.1/Kir3.4 trafficking via Arf6 abrogated the CS effects on IKACh. Cigarette smoke modifies the atrial electrophysiological substrate, leading to arrhythmogenesis, in part, through IKACh activation via an Arf6/PIP5K dependent pathway.
Collapse
Affiliation(s)
- Bojjibabu Chidipi
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, United States of America..
| | - Mengmeng Chang
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, United States of America
| | - Obada Abou-Assali
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, United States of America
| | - Michelle Reiser
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, United States of America
| | - Zhi Tian
- Department of Pharmaceutical Science, USF Health Taneja College of Pharmacy, University of South Florida, Tampa, FL, United States of America
| | - Diane Allen-Gipson
- Department of Pharmaceutical Science, USF Health Taneja College of Pharmacy, University of South Florida, Tampa, FL, United States of America
| | - Sami F Noujaim
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, United States of America
| |
Collapse
|
3
|
Cytohesin-2 mediates group I metabotropic glutamate receptor-dependent mechanical allodynia through the activation of ADP ribosylation factor 6 in the spinal cord. Neurobiol Dis 2021; 159:105466. [PMID: 34390832 DOI: 10.1016/j.nbd.2021.105466] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 07/20/2021] [Accepted: 08/02/2021] [Indexed: 01/15/2023] Open
Abstract
Group I metabotropic glutamate receptors (mGluRs), mGluR1 and mGluR5, in the spinal cord are implicated in nociceptive transmission and plasticity through G protein-mediated second messenger cascades leading to the activation of various protein kinases such as extracellular signal-regulated kinase (ERK). In this study, we demonstrated that cytohesin-2, a guanine nucleotide exchange factor for ADP ribosylation factors (Arfs), is abundantly expressed in subsets of excitatory interneurons and projection neurons in the superficial dorsal horn. Cytohesin-2 is enriched in the perisynapse on the postsynaptic membrane of dorsal horn neurons and forms a protein complex with mGluR5 in the spinal cord. Central nervous system-specific cytohesin-2 conditional knockout mice exhibited reduced mechanical allodynia in inflammatory and neuropathic pain models. Pharmacological blockade of cytohesin catalytic activity with SecinH3 similarly reduced mechanical allodynia and inhibited the spinal activation of Arf6, but not Arf1, in both pain models. Furthermore, cytohesin-2 conditional knockout mice exhibited reduced mechanical allodynia and ERK1/2 activation following the pharmacological activation of spinal mGluR1/5 with 3,5-dihydroxylphenylglycine (DHPG). The present study suggests that cytothesin-2 is functionally associated with mGluR5 during the development of mechanical allodynia through the activation of Arf6 in spinal dorsal horn neurons.
Collapse
|
4
|
Matsuda S, Kakegawa W, Yuzaki M. PhotonSABER: new tool shedding light on endocytosis and learning mechanisms in vivo. Commun Integr Biol 2019; 12:34-37. [PMID: 31143361 PMCID: PMC6527187 DOI: 10.1080/19420889.2019.1586048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 02/15/2019] [Indexed: 11/01/2022] Open
Abstract
In the central nervous system, activity-dependent endocytosis of postsynaptic AMPA-type glutamate receptors (AMPA receptors) is thought to mediate long-term depression (LTD), which is a synaptic plasticity model in various neuronal circuits. However, whether and how AMPA receptor endocytosis and LTD at specific synapses are causally linked to learning and memory in vivo remains unclear. Recently, we developed a new optogenetic tool, PhotonSABER, which could control AMPA receptor endocytosis in temporal, spatial, and cell-type-specific manners at activated synapses. Using PhotonSABER, we found that AMPA receptor endocytosis and LTD at synapses between parallel fibers and Purkinje cells in the cerebellum mediate oculomotor learning. We also found that PhotonSABER could inhibit endocytosis of epidermal growth factor receptors in HeLa cells upon light stimulation. These results demonstrate that PhotonSABER is a powerful tool for analyzing the physiological functions of endocytosis in non-neuronal cells, as well as the roles of LTD in various brain regions.
Collapse
Affiliation(s)
- Shinji Matsuda
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan.,Department of Engineering Science, Graduate School of Informatics and Engineering, The University of Electro-Communications, Tokyo, Japan.,Brain Science Inspired Life Support Research Center (BLSC), The University of Electro-Communications, Tokyo, Japan
| | - Wataru Kakegawa
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
| | - Michisuke Yuzaki
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
| |
Collapse
|
5
|
Bhatt JM, Hancock W, Meissner JM, Kaczmarczyk A, Lee E, Viktorova E, Ramanadham S, Belov GA, Sztul E. Promiscuity of the catalytic Sec7 domain within the guanine nucleotide exchange factor GBF1 in ARF activation, Golgi homeostasis, and effector recruitment. Mol Biol Cell 2019; 30:1523-1535. [PMID: 30943106 PMCID: PMC6724685 DOI: 10.1091/mbc.e18-11-0711] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The integrity of the Golgi and trans-Golgi network (TGN) is disrupted by brefeldin A (BFA), which inhibits the Golgi-localized BFA-sensitive factor (GBF1) and brefeldin A-inhibited guanine nucleotide-exchange factors (BIG1 and BIG2). Using a cellular replacement assay to assess GBF1 functionality without interference from the BIGs, we show that GBF1 alone maintains Golgi architecture; facilitates secretion; activates ADP-ribosylation factor (ARF)1, 3, 4, and 5; and recruits ARF effectors to Golgi membranes. Unexpectedly, GBF1 also supports TGN integrity and recruits numerous TGN-localized ARF effectors. The impact of the catalytic Sec7 domain (Sec7d) on GBF1 functionality was assessed by swapping it with the Sec7d from ARF nucleotide-binding site opener (ARNO)/cytohesin-2, a plasma membrane GEF reported to activate all ARFs. The resulting chimera (GBF1-ARNO-GBF1 [GARG]) targets like GBF1, supports Golgi/TGN architecture, and facilitates secretion. However, unlike GBF1, GARG activates all ARFs (including ARF6) at the Golgi/TGN and recruits additional ARF effectors to the Golgi/TGN. Our results have general implications: 1) GEF's targeting is independent of Sec7d, but Sec7d influence the GEF substrate specificity and downstream effector events; 2) all ARFs have access to all membranes, but are restricted in their distribution by the localization of their activating GEFs; and 3) effector association with membranes requires the coincidental presence of activated ARFs and specific membrane identifiers.
Collapse
Affiliation(s)
- Jay M Bhatt
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - William Hancock
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Justyna M Meissner
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Aneta Kaczmarczyk
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Eunjoo Lee
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Ekaterina Viktorova
- Department of Veterinary Medicine, Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland, College Park, MD 20742
| | - Sasanka Ramanadham
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294.,Comprehensive Diabetes Center, University of Alabama at Birmingham, Birmingham, AL 35294
| | - George A Belov
- Department of Veterinary Medicine, Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland, College Park, MD 20742
| | - Elizabeth Sztul
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| |
Collapse
|
6
|
Luong P, Hedl M, Yan J, Zuo T, Fu TM, Jiang X, Thiagarajah JR, Hansen SH, Lesser CF, Wu H, Abraham C, Lencer WI. INAVA-ARNO complexes bridge mucosal barrier function with inflammatory signaling. eLife 2018; 7:38539. [PMID: 30355448 PMCID: PMC6226287 DOI: 10.7554/elife.38539] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 10/15/2018] [Indexed: 01/28/2023] Open
Abstract
Homeostasis at mucosal surfaces requires cross-talk between the environment and barrier epithelial cells. Disruption of barrier function typifies mucosal disease. Here we elucidate a bifunctional role in coordinating this cross-talk for the inflammatory bowel disease risk-gene INAVA. Both activities require INAVA’s DUF3338 domain (renamed CUPID). CUPID stably binds the cytohesin ARF-GEF ARNO to effect lateral membrane F-actin assembly underlying cell-cell junctions and barrier function. Unexpectedly, when bound to CUPID, ARNO affects F-actin dynamics in the absence of its canonical activity as a guanine nucleotide-exchange factor. Upon exposure to IL-1β, INAVA relocates to form cytosolic puncta, where CUPID amplifies TRAF6-dependent polyubiquitination and inflammatory signaling. In this case, ARNO binding to CUPID negatively-regulates polyubiquitination and the inflammatory response. INAVA and ARNO act similarly in primary human macrophages responding to IL-1β and to NOD2 agonists. Thus, INAVA-CUPID exhibits dual functions, coordinated directly by ARNO, that bridge epithelial barrier function with extracellular signals and inflammation.
Collapse
Affiliation(s)
- Phi Luong
- Division of Gastroenterology, Nutrition and Hepatology, Boston Children's Hospital, Boston, United States.,Department of Pediatrics, Harvard Medical School, Boston, United States
| | - Matija Hedl
- Department of Medicine, Yale University, New Haven, United States
| | - Jie Yan
- Department of Medicine, Yale University, New Haven, United States
| | - Tao Zuo
- Division of Gastroenterology, Nutrition and Hepatology, Boston Children's Hospital, Boston, United States.,Department of Pediatrics, Harvard Medical School, Boston, United States
| | - Tian-Min Fu
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, United States.,Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, United States
| | - Xiaomo Jiang
- Novartis Institutes for Biomedical Research, Cambridge, United States
| | - Jay R Thiagarajah
- Division of Gastroenterology, Nutrition and Hepatology, Boston Children's Hospital, Boston, United States.,Department of Pediatrics, Harvard Medical School, Boston, United States.,Harvard Digestive Disease Center, Harvard Medical School, Boston, United States
| | - Steen H Hansen
- Division of Gastroenterology, Nutrition and Hepatology, Boston Children's Hospital, Boston, United States.,Department of Pediatrics, Harvard Medical School, Boston, United States.,Harvard Digestive Disease Center, Harvard Medical School, Boston, United States
| | - Cammie F Lesser
- Department of Medicine, Division of Infectious Diseases, Massachusetts General Hospital, Cambridge, United States.,Department of Microbiology and Immunobiology, Harvard Medical School, Boston, United States
| | - Hao Wu
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, United States.,Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, United States
| | - Clara Abraham
- Department of Medicine, Yale University, New Haven, United States
| | - Wayne I Lencer
- Division of Gastroenterology, Nutrition and Hepatology, Boston Children's Hospital, Boston, United States.,Department of Pediatrics, Harvard Medical School, Boston, United States.,Harvard Digestive Disease Center, Harvard Medical School, Boston, United States
| |
Collapse
|
7
|
Koubek EJ, Santy LC. ARF1 and ARF6 regulate recycling of GRASP/Tamalin and the Rac1-GEF Dock180 during HGF-induced Rac1 activation. Small GTPases 2016; 9:242-259. [PMID: 27562622 DOI: 10.1080/21541248.2016.1219186] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Hepatocyte growth factor (HGF) is a potent signaling factor that acts on epithelial cells, causing them to dissociate and scatter. This migration is coordinated by a number of small GTPases, such as ARF6 and Rac1. Active ARF6 is required for HGF-stimulated migration and intracellular levels of ARF6-GTP and Rac1-GTP increase following HGF treatment. During migration, cross talk between ARF6 and Rac1 occurs through formation of a multi-protein complex containing the ARF-GEF cytohesin-2, the scaffolding protein GRASP/Tamalin, and the Rac1-GEF Dock180. Previously, the role of ARF6 in this process was unclear. We have now found that ARF6 and ARF1 regulate trafficking of GRASP and Dock180 to the plasma membrane following HGF treatment. Trafficking of GRASP and Dock180 is impaired by blocking ARF6-mediated recycling pathways and is required for HGF-stimulated Rac1 activation. Finally, HGF treatment stimulates association of GRASP and Dock180. Inhibition of ARF6 trafficking pathways traps GRASP and Dock180 as a complex in the cell.
Collapse
Affiliation(s)
- Emily J Koubek
- a Department of Biochemistry and Molecular Biology , The Pennsylvania State University , University Park , PA , USA
| | - Lorraine C Santy
- a Department of Biochemistry and Molecular Biology , The Pennsylvania State University , University Park , PA , USA
| |
Collapse
|
8
|
Kanamarlapudi V. Exchange factor EFA6R requires C-terminal targeting to the plasma membrane to promote cytoskeletal rearrangement through the activation of ADP-ribosylation factor 6 (ARF6). J Biol Chem 2014; 289:33378-90. [PMID: 25296758 PMCID: PMC4246094 DOI: 10.1074/jbc.m113.534156] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
ADP-ribosylation factor 6 (ARF6) small GTPase regulates membrane trafficking and cytoskeleton rearrangements at the plasma membrane (PM) by cycling between the GTP-bound active and GDP-bound inactive conformations. Guanine nucleotide exchange factors (GEFs) activate ARF6. The exchange factor for ARF6 (EFA6) R has been identified as a biomarker for ovarian cancer. EFA6R shares the catalytic Sec7, pleckstrin homology (PH), and coiled coil (CC) domains of the other EFA6 family GEFs. Here we report the functional characterization of EFA6R. Endogenous EFA6R was present in the plasma membrane fraction. The exogenously expressed FLAG- and GFP-tagged EFA6R were targeted to the PM. In vitro, GFP-EFA6R associated weakly but preferentially with phosphatidylinositol 4,5-bisphosphate (PIP2) through the PH domain. EFA6R required both its PH and CC domains localized at the C terminus to target the PM. Consistent with this, EFA6R lacking the CC domain (EFA6RΔCC) was released from the PM into the cytosol upon PIP2 depletion, whereas EFA6R release from the PM required both PIP2 depletion and actin destabilization. These results suggest that the dual targeting via the PH and CC domains is important for the PM localization of EFA6R. EFA6R specifically catalyzed the GTP loading of ARF6 in mammalian cells. Moreover, EFA6R regulated ARF6 localization and thereby actin stress fiber loss. The GEF activity of EFA6R was dependent on the presence of the Sec7 domain. The PH and CC domains were also required for the in vivo GEF activity of EFA6R but could be functionally replaced by the CAAX motif of K-Ras, suggesting a role for these domains in the membrane targeting of EFA6R.
Collapse
Affiliation(s)
- Venkateswarlu Kanamarlapudi
- From the Institute of Life Science 1, College of Medicine, Swansea University, Singleton Park, Swansea SA2 8PP, United Kingdom
| |
Collapse
|
9
|
Chan KC, Ho HH, Lin MC, Yen CH, Huang CN, Huang HP, Wang CJ. Mulberry water extracts inhibit atherosclerosis through suppression of the integrin-β₃/focal adhesion kinase complex and downregulation of nuclear factor κB signaling in vivo and in vitro. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2014; 62:9463-9471. [PMID: 25197764 DOI: 10.1021/jf502942r] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Previous studies have shown that mulberry water extracts (MWEs), which contain polyphenolic compounds, have an antiatherosclerotic effect in vivo and in vitro through stimulating apoptosis of vascular smooth muscle cells (VSMCs). Histological analysis was performed on atherosclerotic lesions from high-cholesterol diet (HCD)-fed rabbits after treatment with 0.5-1% MWEs for 10 weeks. Immunohistochemistry showed that the expressions of SMA, Ras, and matrix metalloproteinase-2 in the VSMCs were dose-dependently inhibited after MWE treatment. The antimigratory effects of MWEs on A7r5 VSMCs were assessed by western blot analysis of migration-related proteins, visualization of F-actin cytoskeleton, and reverse transcription polymerase chain reaction. The results showed that MWEs inhibited VSMC migration through reducing interactions of the integrin-β3/focal adhesion kinase complex, alterations of the cytoskeleton, and downregulation of glycogen synthase kinase 3β/nuclear factor κB signaling. Taken together, MWEs inhibited HCD-induced rabbit atherogenesis through blocking VSMC migration via reducing interactions of integrin-β3 and focal adhesion kinase and downregulating migration-related proteins.
Collapse
Affiliation(s)
- Kuei-Chuan Chan
- Department of Internal Medicine, ∥Department of Family and Community Medicine, and ⊥Department of Medical Research, Chung-Shan Medical University Hospital , Number 110, Section 1, Jianguo North Road, Taichung 402, Taiwan
| | | | | | | | | | | | | |
Collapse
|
10
|
Garcia R, Nguyen L, Brazill D. Dictyostelium discoideum SecG interprets cAMP-mediated chemotactic signals to influence actin organization. Cytoskeleton (Hoboken) 2013; 70:269-80. [PMID: 23564751 PMCID: PMC3693759 DOI: 10.1002/cm.21107] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Revised: 03/04/2013] [Accepted: 03/05/2013] [Indexed: 11/12/2022]
Abstract
Tight control of actin cytoskeletal dynamics is essential for proper cell function and survival. Arf nucleotide binding-site opener (ARNO), a mammalian guanine nucleotide exchange factor for Arf, has been implicated in actin cytoskeletal regulation but its exact role is still unknown. To explore the role of ARNO in this regulation as well as in actin-mediated processes, the Dictyostelium discoideum homolog, SecG, was examined. SecG peaks during aggregation and mound formation. The overexpression of SecG arrests development at the mound stage. SecG overexpressing (SecG OE) cells fail to stream during aggregation. Although carA is expressed, SecG OE cells do not chemotax toward cAMP, indicating SecG is involved in the cellular response to cAMP. This chemotactic defect is specific to cAMP-directed chemotaxis, as SecG OE cells chemotax to folate without impairment and exhibit normal cell motility. The chemotactic defects of the SecG mutants may be due to an impaired cAMP response as evidenced by altered cell polarity and F-actin polymerization after cAMP stimulation. Cells overexpressing SecG have increased filopodia compared to wild type cells, implying that excess SecG causes abnormal organization of F-actin. The general function of the cytoskeleton, however, is not disrupted as the SecG OE cells exhibit proper cell-substrate adhesion. Taken together, the results suggest proper SecG levels are needed for appropriate response to cAMP signaling in order to coordinate F-actin organization during development.
Collapse
Affiliation(s)
- Rebecca Garcia
- Department of Biological Sciences, Center for the Study of Gene Structure and Function, Hunter College and the Graduate Center of the City University of New York, New York, NY 10065
| | - Liem Nguyen
- Department of Biological Sciences, Center for the Study of Gene Structure and Function, Hunter College and the Graduate Center of the City University of New York, New York, NY 10065
| | - Derrick Brazill
- Department of Biological Sciences, Center for the Study of Gene Structure and Function, Hunter College and the Graduate Center of the City University of New York, New York, NY 10065
| |
Collapse
|
11
|
Attar MA, Santy LC. The scaffolding protein GRASP/Tamalin directly binds to Dock180 as well as to cytohesins facilitating GTPase crosstalk in epithelial cell migration. BMC Cell Biol 2013; 14:9. [PMID: 23441967 PMCID: PMC3599651 DOI: 10.1186/1471-2121-14-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Accepted: 02/20/2013] [Indexed: 11/24/2022] Open
Abstract
Background The transition of epithelial cells from their normal non-motile state to a motile one requires the coordinated action of a number of small GTPases. We have previously shown that epithelial cell migration is stimulated by the coordinated activation of Arf and Rac GTPases. This crosstalk depends upon the assembly of a multi-protein complex that contains the Arf-activating protein cytohesin 2/ARNO and the Rac activating protein Dock180. Two scaffolding proteins that bind directly to cytohesin 2 organize this complex. Results We now have found that Rac activation in response to hepatocyte growth factor (HGF) requires cytohesin 2 and Dock180. GRASP/Tamalin is one of the scaffolds that builds the complex containing cytohesin 2 and Dock180. We determine here that the Ala/Pro rich region of GRASP directly interacts with the SH3 domain of Dock180. By binding to both cytohesin 2/ARNO and Dock180, GRASP bridges the guanine nucleotide exchange factors (GEFs) that activate Arf and Rac, thereby promoting Arf-to-Rac signaling. Furthermore, we find that knockdown of GRASP impairs hepatocyte growth factor (HGF)-stimulated Rac activation and HGF-stimulated epithelial migration. Conclusions GRASP binds directly both cytohesin 2 and Dock180 to coordinate their activities, and by doing so promotes crosstalk between Arf and Rac.
Collapse
Affiliation(s)
- Myriam A Attar
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, 208 Althouse Lab, University Park, PA 16802, USA
| | | |
Collapse
|
12
|
Ulloa-Aguirre A, Crépieux P, Poupon A, Maurel MC, Reiter E. Novel pathways in gonadotropin receptor signaling and biased agonism. Rev Endocr Metab Disord 2011; 12:259-74. [PMID: 21526415 DOI: 10.1007/s11154-011-9176-2] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Gonadotropins play a central role in the control of male and female reproduction. Selective agonists and antagonists of gonadotropin receptors would be of great interest for the treatment of infertility or as non steroidal contraceptive. However, to date, only native hormones are being used in assisted reproduction technologies as there is no pharmacological agent available to manipulate gonadotropin receptors. Over the last decade, there has been a growing perception of the complexity associated with gonadotropin receptors' cellular signaling. It is now clear that the Gs/cAMP/PKA pathway is not the sole mechanism that must be taken into account in order to understand these hormones' biological actions. In parallel, consistent with the emerging paradigm of biased agonism, several examples of ligand-mediated selective signaling pathway activation by gonadotropin receptors have been reported. Small molecule ligands, modulating antibodies interacting with the hormones and glycosylation variants of the native glycoproteins have all demonstrated their potential to trigger such selective signaling. Altogether, the available data and emerging concepts give rise to intriguing opportunities towards a more efficient control of reproductive function and associated disorders.
Collapse
Affiliation(s)
- Alfredo Ulloa-Aguirre
- BIOS group, INRA, UMR85, Unité Physiologie de la Reproduction et des Comportements, 37380 Nouzilly, France.
| | | | | | | | | |
Collapse
|
13
|
Quadri SK. Cross talk between focal adhesion kinase and cadherins: role in regulating endothelial barrier function. Microvasc Res 2011; 83:3-11. [PMID: 21864544 DOI: 10.1016/j.mvr.2011.08.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Revised: 07/26/2011] [Accepted: 08/02/2011] [Indexed: 01/11/2023]
Abstract
A layer of endothelial cells attached to their underlying matrices by complex transmembrane structures termed focal adhesion (FA) proteins maintains the barrier property of microvascular endothelium. FAs sense the physical properties of the extracellular matrix (ECM) and organize the cytoskeleton accordingly. The close association of adherens junction (AJ) protein, cadherin, with the cytoskeleton is known to be essential in coordinating the appropriate mechanical properties to cell-cell contacts. Recently, it has become clear that a crosstalk exists between focal adhesion kinase (FAK) and cadherin that regulates signaling at intercellular endothelial junctions. This review discusses recent advances in our understanding of the dynamic regulation of the molecular connections between FAK and the cadherin complex and cadherin-catenin-actin interaction-dependent changes as well as the role of small GTPases in endothelial barrier regulation. This review also discusses how a signaling network regulates a range of cellular processes important for barrier function and diseases.
Collapse
Affiliation(s)
- Sadiqa K Quadri
- Lung Biology Laboratory, Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA.
| |
Collapse
|
14
|
Oh SJ, Santy LC. Differential effects of cytohesins 2 and 3 on beta1 integrin recycling. J Biol Chem 2010; 285:14610-6. [PMID: 20223830 DOI: 10.1074/jbc.m109.043935] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
ADP-ribosylation actor 6 (ARF6) regulates the endocytosis and recycling of a variety of proteins and also promotes peripheral actin rearrangements and cell motility. ARF6 is activated by a large number of guanine nucleotide exchange factors, which likely regulate ARF6 at different locations and during different processes. In this study we investigate the roles of the cytohesin ADP-ribosylation factor (ARF)-guanine nucleotide exchange factors during the recycling of integrin beta1. Intriguingly, we find that knockdown and overexpression of ARNO/cytohesin 2 and GRP1/cytohesin 3 have opposing effects on cell adhesion and spreading on fibronectin and on cell migration. We find that ARNO/cytohesin 2 is required for integrin beta1 recycling, whereas GRP1/cytohesin 3 is dispensable for this process. This is the first demonstration of unique roles for these proteins.
Collapse
Affiliation(s)
- Seung Ja Oh
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | | |
Collapse
|
15
|
Abstract
Glycogen synthase kinase 3 (GSK3) is one of the few master switch kinases that regulate many aspects of cell functions. Recent studies on cell polarization and migration have shown that GSK3 is also essential for proper regulation of these processes. GSK3 influences cell migration as one of the regulators of the spatiotemporally controlled dynamics of the actin cytoskeleton, microtubules, and cell-to-matrix adhesions. In this mini-review, the effects of GSK3 on these three aspects of cell migration will be discussed.
Collapse
Affiliation(s)
- Tong Sun
- Department of Biological Sciences, Florida International University, Miami, FL 33199, USA
| | | | | |
Collapse
|
16
|
Sironi C, Teesalu T, Muggia A, Fontana G, Marino F, Savaresi S, Talarico D. EFA6A encodes two isoforms with distinct biological activities in neuronal cells. J Cell Sci 2009; 122:2108-18. [DOI: 10.1242/jcs.042325] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The processes of neurite extension and remodeling require a close coordination between the cytoskeleton and the cell membranes. The small GTPase ARF6 (ADP-ribosylation factor 6) has a central role in regulating membrane traffic and actin dynamics, and its activity has been demonstrated to be involved in neurite elaboration. EFA6A has been shown to act as a guanine nucleotide exchange factor (GEF) for ARF6. Here, we report that two distinct isoforms of the EFA6A gene are expressed in murine neural tissue: a long isoform of 1025 amino acids (EFA6A), and a short isoform of 393 amino acids (EFA6As). EFA6A encompasses proline-rich regions, a Sec7 domain (mediating GEF activity on ARF6), a PH domain, and a C-terminal region with coiled-coil motifs. EFA6As lacks the Sec7 domain, and it comprises the PH domain and the C-terminal region. The transcript encoding EFA6As is the result of alternative promoter usage. EFA6A and EFA6As have distinct biological activities: upon overexpression in HeLa cells, EFA6A induces membrane ruffles, whereas EFA6As gives rise to cell elongation; in primary cortical neurons EFA6A promotes neurite extension, whereas EFA6As induces dendrite branching. Our findings suggest that EFA6A could participate in neuronal morphogenesis through the regulated expression of two functionally distinct isoforms.
Collapse
Affiliation(s)
- Cristina Sironi
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milan, Italy
| | - Tambet Teesalu
- Vascular Mapping Center, Burnham Institute for Medical Research at University of California Santa Barbara, Santa Barbara, CA 93106, USA
| | - Anna Muggia
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milan, Italy
| | - Gabriele Fontana
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milan, Italy
| | - Fortunata Marino
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milan, Italy
| | - Sara Savaresi
- Department of Biochemistry, University of Zürich, Winterthurer Strasse 190, 8057 Zürich, CH, Switzerland
| | - Daniela Talarico
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milan, Italy
| |
Collapse
|
17
|
Rab11-FIP3 is a Rab11-binding protein that regulates breast cancer cell motility by modulating the actin cytoskeleton. Eur J Cell Biol 2009; 88:325-41. [PMID: 19327867 DOI: 10.1016/j.ejcb.2009.02.186] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2008] [Revised: 01/29/2009] [Accepted: 02/02/2009] [Indexed: 12/19/2022] Open
Abstract
Cell adhesion and motility are very dynamic processes that require the temporal and spatial coordination of many cellular structures. ADP-ribosylation factor 6 (Arf6) has emerged as master regulator of endocytic membrane traffic and cytoskeletal dynamics during cell movement. Recently, a novel Arf6-binding protein known as FIP3/arfophilin/eferin has been identified. In addition to Arf6, FIP3 also interacts with Rab11, a small monomeric GTPase that regulates endocytic membrane transport. Both Arf6 and Rab11 GTPases have been implicated in regulation of cell motility. Here we test the role of FIP3 in breast carcinoma cell motility. First, we demonstrate that FIP3 is associated with recycling endosomes that are present at the leading edge of motile cells. Second, we show that FIP3 is required for the motility of MDA-MB-231 breast carcinoma cells. Third, we demonstrate that FIP3 regulates Rac1-dependent actin cytoskeleton dynamics and modulates the formation and ruffling of lamellipodia. Finally, we demonstrate that FIP3 regulates the localization of Arf6 at the plasma membrane of MDA-MB-231 cells. Based on our data we propose that FIP3 affects cell motility by regulating Arf6 localization to the plasma membrane of the leading edge, thus regulating polarized Rac1 activation and actin dynamics.
Collapse
|
18
|
Tsai PC, Lee SW, Liu YW, Chu CW, Chen KY, Ho JC, Lee FJS. Afi1p functions as an Arf3p polarization-specific docking factor for development of polarity. J Biol Chem 2008; 283:16915-27. [PMID: 18397879 DOI: 10.1074/jbc.m802550200] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
ADP-ribosylation factors (Arfs) are highly conserved small GTPases and are critical components of vesicle trafficking. Yeast Arf3p, despite its similarity to mammalian Arf6, is not required for endocytosis but is involved in polarity development. In this study, we identified an Arf3p interacting protein 1 (Afi1p), which, through its N-terminal conserved region, specifically interacts with GTP-bound Arf3p. Afi1p is distributed asymmetrically at the plasma membrane and is required for polarized distribution of Arf3p but not of an Arf3p guanine nucleotide-exchange factor, Yel1p. However, Afi1p is not required for targeting of Arf3p or Yel1p to the plasma membrane. Like arf3 mutant yeast, afi1 mutant yeast exhibited an abnormal budding pattern and partially delayed actin patch polarization. An Afi1p, (38)KLGP4A-Afi1p, mutated at the Arf3p-binding region, loses its ability to interact with Arf3p and maintain the polarized distribution of Arf3p. Although (38)KLGP4A-Afi1p still possessed a proper polarized distribution, it lost its ability to rescue actin patch polarization in afi1 mutant cells. Our findings demonstrate that Afi1p functions as an Arf3p polarization-specific adapter and participates in development of polarity.
Collapse
Affiliation(s)
- Pei-Chin Tsai
- Institute of Molecular Medicine, School of Medicine, National Taiwan University, Taipei, Taiwan
| | | | | | | | | | | | | |
Collapse
|
19
|
|
20
|
Schweitzer JK, D'Souza-Schorey C. A requirement for ARF6 during the completion of cytokinesis. Exp Cell Res 2005; 311:74-83. [PMID: 16181626 DOI: 10.1016/j.yexcr.2005.07.033] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2005] [Revised: 07/14/2005] [Accepted: 07/25/2005] [Indexed: 12/20/2022]
Abstract
During cancer development, coordinated changes in cell motility and cell cycle progression are required for the gradual transformation of normal cells into cancer cells. Previous studies have shown that ARF6 is a critical regulator of epithelial cell integrity and motility via its role in membrane movement and actin-based cytoskeletal remodeling. Recently, we have found that ARF6 also plays a role during cell division. It localizes to the cleavage furrow and midbody of cells during mitosis, and its activity is regulated during cytokinesis. Here, we investigate the requirement for ARF6 during mitosis and find that depletion of ARF6 using RNA interference disrupts the completion of cytokinesis. This finding demonstrates that ARF6 is essential during the final stages of cytokinesis. In addition, we have identified Ku70, a DNA-binding protein that is required for DNA damage repair, as a new ARF6-interacting protein and found that it is part of a complex with ARF6, especially during mitosis. These results clarify the importance of ARF6 activity during cytokinesis and begin to reveal other molecules that may contribute to the function of ARF6.
Collapse
Affiliation(s)
- Jill Kuglin Schweitzer
- Department of Biological Sciences and the Walther Cancer Institute, University of Notre Dame, 145 Galvin Life Science Bldg, Notre Dame, IN 46556-0369, USA
| | | |
Collapse
|
21
|
Affiliation(s)
- Zahara M Jaffer
- Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111, USA
| | | |
Collapse
|
22
|
Onel S, Bolke L, Klämbt C. TheDrosophilaARF6-GEF Schizo controls commissure formation by regulating Slit. Development 2004; 131:2587-94. [PMID: 15148300 DOI: 10.1242/dev.01147] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The CNS of bilateral symmetric organisms is characterized by intensive contralateral axonal connections. Genetic screens in Drosophila have identified only a few genes required for guiding commissural growth cones toward and across the midline. Two evolutionarily conserved signaling molecules, Netrin and Slit, are expressed in the CNS midline cells. Netrin acts primarily as an attractive signaling cue, whereas Slit mediates repulsive functions. Here, we describe a detailed analysis of the Drosophilagene schizo, which is required for commissure formation. schizo leads to a commissural phenotype reminiscent of netrin mutant embryos. Double-mutant analyses indicate that Netrin and Schizo act independently. The schizo mutant phenotype can be suppressed by either expressing netrin in the CNS midline cells or by a reduction of the slit gene dose, indicating that the balance of attractive and repulsive signaling is impaired in schizo mutants. Overexpression of the schizo RNA in the CNS midline using the GAL4/UAS system leads to a slit phenocopy, suggesting that schizo primarily antagonizes Slit signaling. This is further supported by cell type-specific rescue experiments. The schizo gene generates at least two proteins containing a conserved Sec7 and a pleckstrin homology domain (PH) characteristic for guanine nucleotide exchange factors(GEF) acting on ARF GTPases, which are known to regulate endocytosis.In support of the notion that schizo regulates Slit expression via endocytosis, we found that block of endocytosis leads to a schizo-like phenotype. We thus propose that the balance of the two signaling cues Netrin and Slit can be regulated, controlling membrane dynamics.
Collapse
Affiliation(s)
- Susanne Onel
- Institut für Neurobiologie, Universität Münster, Badestrasse 9, D-48149 Münster, Germany
| | | | | |
Collapse
|
23
|
Kowanetz K, Husnjak K, Höller D, Kowanetz M, Soubeyran P, Hirsch D, Schmidt MHH, Pavelic K, De Camilli P, Randazzo PA, Dikic I. CIN85 associates with multiple effectors controlling intracellular trafficking of epidermal growth factor receptors. Mol Biol Cell 2004; 15:3155-66. [PMID: 15090612 PMCID: PMC452573 DOI: 10.1091/mbc.e03-09-0683] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
CIN85 is a multidomain adaptor protein involved in Cbl-mediated down-regulation of epidermal growth factor (EGF) receptors. CIN85 src homology 3 domains specifically bind to a proline-arginine (PxxxPR) motif in Cbl, and this association seems to be important for EGF receptor endocytosis. Here, we report identification of novel CIN85 effectors, all containing one or more PxxxPR motifs, that are indispensable for their mutual interactions. These effectors include phosphatidyl-inositol phosphatases SHIP-1 and synaptojanin 2B1, Arf GTPase-activating proteins ASAP1 and ARAP3, adaptor proteins Hip1R and STAP1, and a Rho exchange factor, p115Rho GEF. Acting as a molecular scaffold, CIN85 clusters its effectors and recruits them to high-molecular-weight complexes in cytosolic extracts of cells. Further characterization of CIN85 binding to ASAP1 revealed that formation of the complex is independent on cell stimulation. Overexpression of ASAP1 increased EGF receptor recycling, whereas ASAP1 containing mutated PxxxPR motif failed to promote this event. We propose that CIN85 functions as a scaffold molecule that binds to numerous endocytic accessory proteins, thus controlling distinct steps in trafficking of EGF receptors along the endocytic and recycling pathways.
Collapse
Affiliation(s)
- Katarzyna Kowanetz
- Institute of Biochemistry II, Goethe University Medical School, 60590 Frankfurt, Germany
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Li HS, Shome K, Rojas R, Rizzo MA, Vasudevan C, Fluharty E, Santy LC, Casanova JE, Romero G. The guanine nucleotide exchange factor ARNO mediates the activation of ARF and phospholipase D by insulin. BMC Cell Biol 2003; 4:13. [PMID: 12969509 PMCID: PMC212319 DOI: 10.1186/1471-2121-4-13] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2003] [Accepted: 09/11/2003] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Phospholipase D (PLD) is involved in many signaling pathways. In most systems, the activity of PLD is primarily regulated by the members of the ADP-Ribosylation Factor (ARF) family of GTPases, but the mechanism of activation of PLD and ARF by extracellular signals has not been fully established. Here we tested the hypothesis that ARF-guanine nucleotide exchange factors (ARF-GEFs) of the cytohesin/ARNO family mediate the activation of ARF and PLD by insulin. RESULTS Wild type ARNO transiently transfected in HIRcB cells was translocated to the plasma membrane in an insulin-dependent manner and promoted the translocation of ARF to the membranes. ARNO mutants: DeltaCC-ARNO and CC-ARNO were partially translocated to the membranes while DeltaPH-ARNO and PH-ARNO could not be translocated to the membranes. Sec7 domain mutants of ARNO did not facilitate the ARF translocation. Overexpression of wild type ARNO significantly increased insulin-stimulated PLD activity, and mutations in the Sec7 and PH domains, or deletion of the PH or CC domains inhibited the effects of insulin. CONCLUSIONS Small ARF-GEFs of the cytohesin/ARNO family mediate the activation of ARF and PLD by the insulin receptor.
Collapse
Affiliation(s)
- Hai-Sheng Li
- Departments of Pharmacology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261 USA
| | - Kuntala Shome
- Departments of Pharmacology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261 USA
| | - Raúl Rojas
- Departments of Pharmacology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261 USA
- Cell Biology and Physiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261 USA
| | - Megan A Rizzo
- Departments of Pharmacology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261 USA
| | - Chandrasekaran Vasudevan
- Departments of Pharmacology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261 USA
| | - Eric Fluharty
- Departments of Pharmacology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261 USA
| | - Lorraine C Santy
- Department of Cell Biology, University of Virginia School of Medicine, Charlottesville, VA 22908 USA
| | - James E Casanova
- Department of Cell Biology, University of Virginia School of Medicine, Charlottesville, VA 22908 USA
| | - Guillermo Romero
- Departments of Pharmacology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261 USA
| |
Collapse
|
25
|
Lu L, Hong W. Interaction of Arl1-GTP with GRIP domains recruits autoantigens Golgin-97 and Golgin-245/p230 onto the Golgi. Mol Biol Cell 2003; 14:3767-81. [PMID: 12972563 PMCID: PMC196566 DOI: 10.1091/mbc.e03-01-0864] [Citation(s) in RCA: 133] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
A cellular role and the mechanism of action for small GTPase Arl1 have been defined. Arl1-GTP interacts with the GRIP domains of Golgin-97 and Golgin-245, a process dependent on conserved residues of the GRIP domains that are important for Golgi targeting. The switch II region of Arl1 confers the specificity of this interaction. Arl1-GTP mediates Golgi recruitment of Golgin-97 in a switch II-dependent manner, whereas tethering Arl1-GTP onto endosomes can mediate endosomal targeting of Golgin-97. Golgin-97 and Golgin-245 are dissociated from the Golgi when Arl1 is knocked-down by its siRNA. Arl1-GTP thus functions to recruit Golgin-97 and Golgin-245 onto the Golgi via interacting with their GRIP domains.
Collapse
Affiliation(s)
- Lei Lu
- Membrane Biology Laboratory, Institute of Molecular and Cell Biology, Singapore 117609, Singapore
| | | |
Collapse
|
26
|
Wennerberg K, Forget MA, Ellerbroek SM, Arthur WT, Burridge K, Settleman J, Der CJ, Hansen SH. Rnd proteins function as RhoA antagonists by activating p190 RhoGAP. Curr Biol 2003; 13:1106-15. [PMID: 12842009 PMCID: PMC6918695 DOI: 10.1016/s0960-9822(03)00418-4] [Citation(s) in RCA: 185] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND The Rnd proteins Rnd1, Rnd2, and Rnd3 (RhoE) comprise a unique branch of Rho-family G-proteins that lack intrinsic GTPase activity and consequently remain constitutively "active." Prior studies have suggested that Rnd proteins play pivotal roles in cell regulation by counteracting the biological functions of the RhoA GTPase, but the molecular basis for this antagonism is unknown. Possible mechanisms by which Rnd proteins could function as RhoA antagonists include sequestration of RhoA effector molecules, inhibition of guanine nucleotide exchange factors, and activation of GTPase-activating proteins (GAPs) for RhoA. However, effector molecules of Rnd proteins with such properties have not been identified. RESULTS Here we identify p190 RhoGAP (p190), the most abundant GAP for RhoA in cells, as an interactor with Rnd proteins and show that this interaction is mediated by a p190 region that is distinct from the GAP domain. Using Rnd3-RhoA chimeras and Rnd3 mutants defective in p190 binding, as well as p190-deficient cells, we demonstrate that the cellular effects of Rnd expression are mediated by p190. We moreover show that Rnd proteins increase the GAP activity of p190 toward GTP bound RhoA and, finally, demonstrate that expression of Rnd3 leads to reduced cellular levels of RhoA-GTP by a p190-dependent mechanism. CONCLUSIONS Our results identify p190 RhoGAPs as effectors of Rnd proteins and demonstrate a novel mechanism by which Rnd proteins function as antagonists of RhoA.
Collapse
Affiliation(s)
- Krister Wennerberg
- Department of Cell and Developmental Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | | | - Shawn M. Ellerbroek
- Department of Cell and Developmental Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - William T. Arthur
- Department of Cell and Developmental Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Keith Burridge
- Department of Cell and Developmental Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | | | - Channing J. Der
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Steen H. Hansen
- Boston Biomedical Research Institute, Watertown, MA 02472
- Corresponding author: Steen H. Hansen, MD, DMSc, Boston Biomedical Research Institute, 64 Grove Street, Watertown, MA 02472-2829, 617-658-7781 (tel) • 617-972-1761 (fax),
| |
Collapse
|
27
|
Niedergang F, Colucci-Guyon E, Dubois T, Raposo G, Chavrier P. ADP ribosylation factor 6 is activated and controls membrane delivery during phagocytosis in macrophages. J Cell Biol 2003; 161:1143-50. [PMID: 12810696 PMCID: PMC2172982 DOI: 10.1083/jcb.200210069] [Citation(s) in RCA: 144] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Engulfment of particles by phagocytes is induced by their interaction with specific receptors on the cell surface, which leads to actin polymerization and the extension of membrane protrusions to form a closed phagosome. Membrane delivery from internal pools is considered to play an important role in pseudopod extension during phagocytosis. Here, we report that endogenous ADP ribosylation factor 6 (ARF6), a small GTP-binding protein, undergoes a sharp and transient activation in macrophages when phagocytosis was initiated via receptors for the Fc portion of immunoglobulins (FcRs). A dominant-negative mutant of ARF6 (T27N mutation) dramatically affected FcR-mediated phagocytosis. Expression of ARF6-T27N lead to a reduction in the focal delivery of vesicle-associated membrane protein 3+ endosomal recycling membranes at phagocytosis sites, whereas actin polymerization was unimpaired. This resulted in an early blockade in pseudopod extension and accumulation of intracellular vesicles, as observed by electron microscopy. We conclude that ARF6 is a major regulator of membrane recycling during phagocytosis.
Collapse
Affiliation(s)
- Florence Niedergang
- Membrane and Cytoskeleton Dynamics Laboratory, UMR144 CNRS, Institut Curie, 26 rue d'Ulm, F-75248 Paris cedex 05, France.
| | | | | | | | | |
Collapse
|
28
|
Bernards A. GAPs galore! A survey of putative Ras superfamily GTPase activating proteins in man and Drosophila. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1603:47-82. [PMID: 12618308 DOI: 10.1016/s0304-419x(02)00082-3] [Citation(s) in RCA: 154] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Typical members of the Ras superfamily of small monomeric GTP-binding proteins function as regulators of diverse processes by cycling between biologically active GTP- and inactive GDP-bound conformations. Proteins that control this cycling include guanine nucleotide exchange factors or GEFs, which activate Ras superfamily members by catalyzing GTP for GDP exchange, and GTPase activating proteins or GAPs, which accelerate the low intrinsic GTP hydrolysis rate of typical Ras superfamily members, thus causing their inactivation. Two among the latter class of proteins have been implicated in common genetic disorders associated with an increased cancer risk, neurofibromatosis-1, and tuberous sclerosis. To facilitate genetic analysis, I surveyed Drosophila and human sequence databases for genes predicting proteins related to GAPs for Ras superfamily members. Remarkably, close to 0.5% of genes in both species (173 human and 64 Drosophila genes) predict proteins related to GAPs for Arf, Rab, Ran, Rap, Ras, Rho, and Sar family GTPases. Information on these genes has been entered into a pair of relational databases, which can be used to identify evolutionary conserved proteins that are likely to serve basic biological functions, and which can be updated when definitive information on the coding potential of both genomes becomes available.
Collapse
Affiliation(s)
- André Bernards
- Massachusetts General Hospital Cancer Center, Building 149, 13th Street, Charlestown, MA 02129-2000, USA.
| |
Collapse
|
29
|
Chies R, Nobbio L, Edomi P, Schenone A, Schneider C, Brancolini C. Alterations in the Arf6-regulated plasma membrane endosomal recycling pathway in cells overexpressing the tetraspan protein Gas3/PMP22. J Cell Sci 2003; 116:987-99. [PMID: 12584243 DOI: 10.1242/jcs.00326] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Growth arrest specific 3 (Gas3)/peripheral myelin protein 22 (PMP22) is a component of the compact peripheral nerve myelin, and mutations affecting gas3/PMP22 gene are responsible for a group of peripheral neuropathies in humans. We have performed in vivo imaging in order to investigate in detail the phenotype induced by Gas3/PMP22 overexpression in cultured cells. Here we show that Gas3/PMP22 triggers the accumulation of vacuoles, before the induction of cell death or of changes in cell spreading. Overexpressed Gas3/PMP22 accumulates into two distinct types of intracellular membrane compartments. Gas3/PMP2 accumulates within late endosomes close to the juxtanuclear region, whereas in the proximity of the cell periphery, it induces the formation of actin/phosphatidylinositol (4,5)-bisphosphate (PIP(2))-positive large vacuoles. Gas3/PMP22-induced vacuoles do not contain transferrin receptor, but instead they trap membrane proteins that normally traffic through the ADP-ribosylation factor 6 (Arf6) endosomal compartment. Arf6 and Arf6-Q67L co-localize with Gas3/PMP22 in these vacuoles, and the dominant negative mutant of Arf6, T27N, blocks the appearance of vacuoles in response to Gas3/PMP22, but not its accumulation in the late endosomes. Finally a point mutant of Gas3/PMP22 responsible for the Charcot-Marie-Tooth 1A disease is unable to trigger the accumulation of PIP(2)-positive vacuoles. Altogether these results suggest that increased Gas3/PMP22 levels can alter membrane traffic of the Arf6 plasma-membrane-endosomal recycling pathway and show that, similarly to other tetraspan proteins, Gas3/PMP22 can accumulate in the late endosomes.
Collapse
Affiliation(s)
- Romina Chies
- Dipartimento di Scienze e Tecnologie Biomediche, Sezione di Biologia, Universita' di Udine, P.le Kolbe 4, 33100 Udine, Italy
| | | | | | | | | | | |
Collapse
|
30
|
Yamao T, Noguchi T, Takeuchi O, Nishiyama U, Morita H, Hagiwara T, Akahori H, Kato T, Inagaki K, Okazawa H, Hayashi Y, Matozaki T, Takeda K, Akira S, Kasuga M. Negative regulation of platelet clearance and of the macrophage phagocytic response by the transmembrane glycoprotein SHPS-1. J Biol Chem 2002; 277:39833-9. [PMID: 12167615 DOI: 10.1074/jbc.m203287200] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
SHPS-1 is a receptor-type glycoprotein that binds and activates the protein-tyrosine phosphatases SHP-1 and SHP-2, and thereby negatively modulates intracellular signaling initiated by various cell surface receptors coupled to tyrosine kinases. SHPS-1 also regulates intercellular communication in the neural and immune systems through its association with CD47 (integrin-associated protein) on adjacent cells. Furthermore, recent studies with fibroblasts derived from mice expressing an SHPS-1 mutant that lacks most of the cytoplasmic region suggested that the intact protein contributes to cytoskeletal function. Mice homozygous for this SHPS-1 mutation have now been shown to manifest thrombocytopenia. These animals did not exhibit a defect in megakaryocytopoiesis or in platelet production. However, platelets were cleared from the bloodstream more rapidly in the mutant mice than in wild-type animals. Furthermore, peritoneal macrophages from the mutant mice phagocytosed red blood cells more effectively than did those from wild-type mice; in addition, they exhibited an increase both in the rate of cell spreading and in the formation of filopodia-like structures at the cell periphery. These results indicate that SHPS-1 both contributes to the survival of circulating platelets and down-regulates the macrophage phagocytic response.
Collapse
Affiliation(s)
- Takuji Yamao
- Division of Diabetes, Digestive, and Kidney Diseases, Department of Clinical Molecular Medicine, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Abstract
Within the secretory pathway, most proteins involved in vesicle formation, motor recruitment and vesicle tethering are not integral membrane proteins but, rather, peripheral membrane proteins recruited to the relevant organelles from the cytosol. From recent studies on diverse organelles, it appears that such recruitment is usually mediated by binding to a labile determinant, such as an activated G protein or a short-lived lipid species, whose distribution is restricted to a single organelle. This suggests that these determinants are what specify organelle identity, and raises interesting questions about how they are generated in an organelle-specific fashion.
Collapse
Affiliation(s)
- Sean Munro
- MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, uk.
| |
Collapse
|
32
|
Kawamoto K, Yoshida Y, Tamaki H, Torii S, Shinotsuka C, Yamashina S, Nakayama K. GBF1, a guanine nucleotide exchange factor for ADP-ribosylation factors, is localized to the cis-Golgi and involved in membrane association of the COPI coat. Traffic 2002; 3:483-95. [PMID: 12047556 DOI: 10.1034/j.1600-0854.2002.30705.x] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Formation of coated carrier vesicles, such as COPI-coated vesicles from the cis-Golgi, is triggered by membrane binding of the GTP-bound form of ADP-ribosylation factors. This process is blocked by brefeldin A, which is an inhibitor of guanine nucleotide exchange factors for ADP-ribosylation factor. GBF1 is one of the guanine nucleotide-exchange factors for ADP-ribosylation factor and is localized in the Golgi region. In the present study, we have determined the detailed subcellular localization of GBF1. Immunofluorescence microscopy of cells treated with nocodazole or incubated at 15 degrees C has suggested that GBF1 behaves similarly to proteins recycling between the cis-Golgi and the endoplasmic reticulum. Immunoelectron microscopy has revealed that GBF1 localizes primarily to vesicular and tubular structures apposed to the cis-face of Golgi stacks and minor fractions to the Golgi stacks. GBF1 overexpressed in cells causes recruitment of class I and class II ADP-ribosylation factors onto Golgi membranes. Furthermore, overexpressed GBF1 antagonizes various effects of brefeldin A, such as inhibition of membrane recruitment of ADP-ribosylation factors and the COPI coat, and redistribution of Golgi-resident and itinerant proteins. These observations indicate that GBF1 is involved in the formation of COPI-coated vesicles from the cis-Golgi or the pre-Golgi intermediate compartment through activating ADP-ribosylation factors.
Collapse
Affiliation(s)
- Kazumasa Kawamoto
- Institute of Biological Sciences and Gene Research Center, University of Tsukuba, Tsukuba Science City, Ibaraki 305-8572, Japan
| | | | | | | | | | | | | |
Collapse
|
33
|
Hunzicker-Dunn M, Gurevich VV, Casanova JE, Mukherjee S. ARF6: a newly appreciated player in G protein-coupled receptor desensitization. FEBS Lett 2002; 521:3-8. [PMID: 12067715 DOI: 10.1016/s0014-5793(02)02822-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The luteinizing hormone/choriogonadotropin hormone receptor (LH/CG R) signals to regulate ovulation, corpus luteum formation, and fetal survival during pregnancy. Agonist binding to the LH/CG R is poorly reversible, emphasizing the importance of a cellular mechanism to temper signaling by a potentially persistently active receptor. Like other G protein-coupled receptors (GPCRs), signaling by this receptor is modulated by its binding of an arrestin. We have identified ADP ribosylation factor 6 (ARF6) as a protein whose activation state is regulated by the LH/CG R and which functions to regulate the availability of plasma membrane-docked arrestin 2 to this receptor. We hypothesize that ARF6 might also serve GPCRs other than the LH/CG R to regulate the availability of arrestin 2 for receptor desensitization.
Collapse
Affiliation(s)
- Mary Hunzicker-Dunn
- Department of Cell and Molecular Biology, Northwestern University Medical School, 303 East Chicago Avenue, Chicago, IL 60611, USA.
| | | | | | | |
Collapse
|