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Rasche R, Apken LH, Michalke E, Kümmel D, Oeckinghaus A. κB-Ras proteins are fast-exchanging GTPases and function via nucleotide-independent binding of Ral GTPase-activating protein complexes. FEBS Lett 2024; 598:1769-1782. [PMID: 38604989 DOI: 10.1002/1873-3468.14860] [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: 09/26/2023] [Revised: 01/29/2024] [Accepted: 02/27/2024] [Indexed: 04/13/2024]
Abstract
κB-Ras (NF-κB inhibitor-interacting Ras-like protein) GTPases are small Ras-like GTPases but harbor interesting differences in important sequence motifs. They act in a tumor-suppressive manner as negative regulators of Ral (Ras-like) GTPase and NF-κB signaling, but little is known about their mode of function. Here, we demonstrate that, in contrast to predictions based on primary structure, κB-Ras GTPases possess hydrolytic activity. Combined with low nucleotide affinity, this renders them fast-cycling GTPases that are predominantly GTP-bound in cells. We characterize the impact of κB-Ras mutations occurring in tumors and demonstrate that nucleotide binding affects κB-Ras stability but is not strictly required for RalGAP (Ral GTPase-activating protein) binding. This demonstrates that κB-Ras control of RalGAP/Ral signaling occurs in a nucleotide-binding- and switch-independent fashion.
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Affiliation(s)
- René Rasche
- Institute of Biochemistry, University Münster, Germany
| | | | - Esther Michalke
- Institute of Molecular Tumor Biology, University Münster, Germany
| | - Daniel Kümmel
- Institute of Biochemistry, University Münster, Germany
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2
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Shi P, Tian J, Mallinger JC, Ling D, Deleyrolle LP, McIntyre JC, Caspary T, Breunig JJ, Sarkisian MR. Increasing Ciliary ARL13B Expression Drives Active and Inhibitor-Resistant Smoothened and GLI into Glioma Primary Cilia. Cells 2023; 12:2354. [PMID: 37830570 PMCID: PMC10571910 DOI: 10.3390/cells12192354] [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: 07/19/2023] [Revised: 09/14/2023] [Accepted: 09/20/2023] [Indexed: 10/14/2023] Open
Abstract
ADP-ribosylation factor-like protein 13B (ARL13B), a regulatory GTPase and guanine exchange factor (GEF), enriches in primary cilia and promotes tumorigenesis in part by regulating Smoothened (SMO), GLI, and Sonic Hedgehog (SHH) signaling. Gliomas with increased ARL13B, SMO, and GLI2 expression are more aggressive, but the relationship to cilia is unclear. Previous studies have showed that increasing ARL13B in glioblastoma cells promoted ciliary SMO accumulation, independent of exogenous SHH addition. Here, we show that SMO accumulation is due to increased ciliary, but not extraciliary, ARL13B. Increasing ARL13B expression promotes the accumulation of both activated SMO and GLI2 in glioma cilia. ARL13B-driven increases in ciliary SMO and GLI2 are resistant to SMO inhibitors, GDC-0449, and cyclopamine. Surprisingly, ARL13B-induced changes in ciliary SMO/GLI2 did not correlate with canonical changes in downstream SHH pathway genes. However, glioma cell lines whose cilia overexpress WT but not guanine exchange factor-deficient ARL13B, display reduced INPP5e, a ciliary membrane component whose depletion may favor SMO/GLI2 enrichment. Glioma cells overexpressing ARL13B also display reduced ciliary intraflagellar transport 88 (IFT88), suggesting that altered retrograde transport could further promote SMO/GLI accumulation. Collectively, our data suggest that factors increasing ARL13B expression in glioma cells may promote both changes in ciliary membrane characteristics and IFT proteins, leading to the accumulation of drug-resistant SMO and GLI. The downstream targets and consequences of these ciliary changes require further investigation.
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Affiliation(s)
- Ping Shi
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, FL 32610, USA; (P.S.); (J.T.); (J.C.M.); (D.L.); (J.C.M.)
| | - Jia Tian
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, FL 32610, USA; (P.S.); (J.T.); (J.C.M.); (D.L.); (J.C.M.)
| | - Julianne C. Mallinger
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, FL 32610, USA; (P.S.); (J.T.); (J.C.M.); (D.L.); (J.C.M.)
| | - Dahao Ling
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, FL 32610, USA; (P.S.); (J.T.); (J.C.M.); (D.L.); (J.C.M.)
| | - Loic P. Deleyrolle
- Preston A. Wells Jr. Center for Brain Tumor Therapy, University of Florida College of Medicine, Gainesville, FL 32610, USA;
- Department of Neurosurgery, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Jeremy C. McIntyre
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, FL 32610, USA; (P.S.); (J.T.); (J.C.M.); (D.L.); (J.C.M.)
| | - Tamara Caspary
- Department of Human Genetics, Emory School of Medicine, Atlanta, GA 30322, USA;
| | - Joshua J. Breunig
- Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA;
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
- Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Matthew R. Sarkisian
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, FL 32610, USA; (P.S.); (J.T.); (J.C.M.); (D.L.); (J.C.M.)
- Preston A. Wells Jr. Center for Brain Tumor Therapy, University of Florida College of Medicine, Gainesville, FL 32610, USA;
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3
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Abstract
Phosphoinositides (PIs) are phospholipids derived from phosphatidylinositol. PIs are regulated via reversible phosphorylation, which is directed by the opposing actions of PI kinases and phosphatases. PIs constitute a minor fraction of the total cellular lipid pool but play pleiotropic roles in multiple aspects of cell biology. Genetic mutations of PI regulatory enzymes have been identified in rare congenital developmental syndromes, including ciliopathies, and in numerous human diseases, such as cancer and metabolic and neurological disorders. Accordingly, PI regulatory enzymes have been targeted in the design of potential therapeutic interventions for human diseases. Recent advances place PIs as central regulators of membrane dynamics within functionally distinct subcellular compartments. This brief review focuses on the emerging role PIs play in regulating cell signaling within the primary cilium and in directing transfer of molecules at interorganelle membrane contact sites and identifies new roles for PIs in subcellular spaces.
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Affiliation(s)
- Elizabeth Michele Davies
- Cancer Program, Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Victoria 3800, Australia
| | - Christina Anne Mitchell
- Cancer Program, Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Victoria 3800, Australia
| | - Harald Alfred Stenmark
- Department of Molecular Cell Biology, Institute for Cancer Research. The Norwegian Radium Hospital, Montebello, N-0379 Oslo, Norway
- Centre for Cancer Cell Reprogramming, Faculty of Medicine, University of Oslo, Montebello, N-0379 Oslo, Norway
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Terry TT, Gigante ED, Alexandre CM, Brewer KM, Engle SE, Yue X, Berbari NF, Vaisse C, Caspary T. Ciliary ARL13B prevents obesity in mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.02.551695. [PMID: 37577625 PMCID: PMC10418222 DOI: 10.1101/2023.08.02.551695] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Cilia are near ubiquitous small, cellular appendages critical for cell-to-cell communication. As such, they are involved in diverse developmental and homeostatic processes, including energy homeostasis. ARL13B is a regulatory GTPase highly enriched in cilia. Mice expressing an engineered ARL13B variant, ARL13BV358A which retains normal biochemical activity, display no detectable ciliary ARL13B. Surprisingly, these mice become obese. Here, we measured body weight, food intake, and blood glucose levels to reveal these mice display hyperphagia and metabolic defects. We showed that ARL13B normally localizes to cilia of neurons in specific brain regions and pancreatic cells but is excluded from these cilia in the Arl13bV358A/V358A model. In addition to its GTPase function, ARL13B acts as a guanine nucleotide exchange factor (GEF) for ARL3. To test whether ARL13B's GEF activity is required to regulate body weight, we analyzed the body weight of mice expressing ARL13BR79Q, a variant that lacks ARL13B GEF activity for ARL3. We found no difference in body weight. Taken together, our results show that ARL13B functions within cilia to control body weight and that this function does not depend on its role as a GEF for ARL3. Controlling the subcellular localization of ARL13B in the engineered mouse model, ARL13BV358A, enables us to define the cilia-specific role of ARL13B in regulating energy homeostasis.
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Affiliation(s)
- Tiffany T. Terry
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Suite 301, Atlanta, GA 30322, USA
| | - Eduardo D. Gigante
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Suite 301, Atlanta, GA 30322, USA
- Graduate Program in Neuroscience, Laney Graduate School, Emory University, 201 Dowman Dr., Atlanta, GA 30307, USA
- Present address: Department of Biology, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Coralie M. Alexandre
- Diabetes Center and Department of Medicine, University of California San Francisco, San Francisco, California 94143
| | - Kathryn M. Brewer
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana 46202
| | - Staci E. Engle
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana 46202
| | - Xinyu Yue
- Diabetes Center and Department of Medicine, University of California San Francisco, San Francisco, California 94143
| | - Nicolas F. Berbari
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana 46202
| | - Christian Vaisse
- Diabetes Center and Department of Medicine, University of California San Francisco, San Francisco, California 94143
| | - Tamara Caspary
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Suite 301, Atlanta, GA 30322, USA
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Van Sciver RE, Long AB, Katz HG, Gigante ED, Caspary T. Ciliary ARL13B inhibits developmental kidney cystogenesis in mouse. Dev Biol 2023; 500:1-9. [PMID: 37209936 PMCID: PMC10330881 DOI: 10.1016/j.ydbio.2023.05.004] [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: 02/08/2023] [Revised: 05/15/2023] [Accepted: 05/17/2023] [Indexed: 05/22/2023]
Abstract
ARL13B is a small GTPase enriched in cilia. Deletion of Arl13b in mouse kidney results in renal cysts and an associated absence of primary cilia. Similarly, ablation of cilia leads to kidney cysts. To investigate whether ARL13B functions from within cilia to direct kidney development, we examined kidneys of mice expressing an engineered cilia-excluded ARL13B variant, ARL13BV358A. These mice retained renal cilia and developed cystic kidneys. Because ARL13B functions as a guanine nucleotide exchange factor (GEF) for ARL3, we examined kidneys of mice expressing an ARL13B variant that lacks ARL3 GEF activity, ARL13BR79Q. We found normal kidney development with no evidence of cysts in these mice. Taken together, our results show that ARL13B functions within cilia to inhibit renal cystogenesis during mouse development, and that this function does not depend on its role as a GEF for ARL3.
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Affiliation(s)
- Robert E Van Sciver
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Suite 301, Atlanta, GA, 30322, USA.
| | - Alyssa B Long
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Suite 301, Atlanta, GA, 30322, USA.
| | - Harrison G Katz
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Suite 301, Atlanta, GA, 30322, USA; Department of Biology, Brown University, Providence, RI, 02912, USA.
| | - Eduardo D Gigante
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Suite 301, Atlanta, GA, 30322, USA; Graduate Program in Neuroscience, Emory University School of Medicine, 615 Michael Street, Suite 301, Atlanta, GA, 30322, USA; Department of Biology, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
| | - Tamara Caspary
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Suite 301, Atlanta, GA, 30322, USA.
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Mahbub L, Kozlov G, Zong P, Lee EL, Tetteh S, Nethramangalath T, Knorn C, Jiang J, Shahsavan A, Yue L, Runnels L, Gehring K. Structural insights into regulation of CNNM-TRPM7 divalent cation uptake by the small GTPase ARL15. eLife 2023; 12:e86129. [PMID: 37449820 PMCID: PMC10348743 DOI: 10.7554/elife.86129] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 07/02/2023] [Indexed: 07/18/2023] Open
Abstract
Cystathionine-β-synthase (CBS)-pair domain divalent metal cation transport mediators (CNNMs) are an evolutionarily conserved family of magnesium transporters. They promote efflux of Mg2+ ions on their own and influx of divalent cations when expressed with the transient receptor potential ion channel subfamily M member 7 (TRPM7). Recently, ADP-ribosylation factor-like GTPase 15 (ARL15) has been identified as CNNM-binding partner and an inhibitor of divalent cation influx by TRPM7. Here, we characterize ARL15 as a GTP and CNNM-binding protein and demonstrate that ARL15 also inhibits CNNM2 Mg2+ efflux. The crystal structure of a complex between ARL15 and CNNM2 CBS-pair domain reveals the molecular basis for binding and allowed the identification of mutations that specifically block binding. A binding deficient ARL15 mutant, R95A, failed to inhibit CNNM and TRPM7 transport of Mg2+ and Zn2+ ions. Structural analysis and binding experiments with phosphatase of regenerating liver 2 (PRL2 or PTP4A2) showed that ARL15 and PRLs compete for binding CNNM to coordinate regulation of ion transport by CNNM and TRPM7.
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Affiliation(s)
- Luba Mahbub
- Department of Biochemistry, McGill UniversityMontrealCanada
- Centre de recherche en biologie structurale, McGill UniversityMontréalCanada
| | - Guennadi Kozlov
- Department of Biochemistry, McGill UniversityMontrealCanada
- Centre de recherche en biologie structurale, McGill UniversityMontréalCanada
| | - Pengyu Zong
- Department of Cell Biology, UCONN Health CenterFarmingtonUnited States
| | - Emma L Lee
- Department of Biochemistry, McGill UniversityMontrealCanada
- Centre de recherche en biologie structurale, McGill UniversityMontréalCanada
| | - Sandra Tetteh
- Rutgers-Robert Wood Johnson Medical SchoolPiscatawayUnited States
| | | | - Caroline Knorn
- Department of Biochemistry, McGill UniversityMontrealCanada
- Centre de recherche en biologie structurale, McGill UniversityMontréalCanada
| | - Jianning Jiang
- Department of Biochemistry, McGill UniversityMontrealCanada
- Centre de recherche en biologie structurale, McGill UniversityMontréalCanada
| | - Ashkan Shahsavan
- Department of Biochemistry, McGill UniversityMontrealCanada
- Centre de recherche en biologie structurale, McGill UniversityMontréalCanada
| | - Lixia Yue
- Department of Cell Biology, UCONN Health CenterFarmingtonUnited States
| | - Loren Runnels
- Rutgers-Robert Wood Johnson Medical SchoolPiscatawayUnited States
| | - Kalle Gehring
- Department of Biochemistry, McGill UniversityMontrealCanada
- Centre de recherche en biologie structurale, McGill UniversityMontréalCanada
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7
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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.
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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
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8
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Van Sciver RE, Long AB, Katz HG, Gigante ED, Caspary T. Ciliary ARL13B inhibits developmental kidney cystogenesis in mouse. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.08.527739. [PMID: 36798281 PMCID: PMC9934666 DOI: 10.1101/2023.02.08.527739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
ARL13B is a small GTPase enriched in cilia. Deletion of Arl13b in mouse kidney results in renal cysts and an associated absence of primary cilia. Similarly, ablation of cilia leads to kidney cysts. To investigate whether ARL13B functions from within cilia to direct kidney development, we examined kidneys of mice expressing an engineered cilia-excluded ARL13B variant, ARL13BV358A. These mice retained renal cilia and developed cystic kidneys. Because ARL13B functions as a guanine nucleotide exchange factor (GEF) for ARL3, we examined kidneys of mice expressing an ARL13B variant that lacks ARL3 GEF activity, ARL13BR79Q. We found normal kidney development with no evidence of cysts in these mice. Taken together, our results show that ARL13B functions within cilia to inhibit renal cystogenesis during mouse development, and that this function does not depend on its role as a GEF for ARL3.
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Affiliation(s)
- Robert E. Van Sciver
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Suite 301, Atlanta, GA 30322, USA
| | - Alyssa B. Long
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Suite 301, Atlanta, GA 30322, USA
| | - Harrison G. Katz
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Suite 301, Atlanta, GA 30322, USA
- Present address: Department of Biology, Brown University, Providence, RI 02912, USA
| | - Eduardo D. Gigante
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Suite 301, Atlanta, GA 30322, USA
- Graduate Program in Neuroscience, Emory University School of Medicine, 615 Michael Street, Suite 301, Atlanta, GA 30322, USA
- Present address: Department of Biology, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Tamara Caspary
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Suite 301, Atlanta, GA 30322, USA
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9
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Lin T, Sun Y. Arl13b promotes the proliferation, migration, osteogenesis, and mechanosensation of osteoblasts. Tissue Cell 2023; 82:102088. [PMID: 37058812 DOI: 10.1016/j.tice.2023.102088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 03/27/2023] [Accepted: 04/10/2023] [Indexed: 04/16/2023]
Abstract
Primary cilia are microtubule-based organelles presenting on the surface of most postmitotic mammalian cells. As being signaling hubs and sensory organelles, primary cilia can respond to mechanical and chemical stimuli from the extracellular environment. Arl13b (ADP-ribosylation factor-like 13B), an atypical Arf/Arl family GTPase, was identified in genetic screening as a protein essential for maintaining the integrity of cilia and neural tubes. Previous studies on Arl13b have mostly focused on its role in the development of neural tubes, polycystic kidneys, and tumors, but no role in bone patterns was described. This study reported the essential roles of Arl13b in bone formation and osteogenic differentiation. Arl13b was highly expressed in bone tissues and osteoblasts, positively correlated with osteogenic activity during bone development. Furthermore, Arl13b was essential for primary cilium maintenance and Hedgehog signaling activation in osteoblasts. Arl13b knockdown in osteoblasts decreased the length of primary cilia and the upregulated levels of Gli1, Smo, and Ptch1 upon Smo agonist treatment. Additionally, Arl13b knockdown inhibited cell proliferation and migration. Moreover, Arl13b mediated osteogenesis and cell mechanosensation. Cyclic tension strain upregulated the Arl13b expression. Arl13b knockdown suppressed osteogenesis and mitigated cyclic tension strain-induced osteogenesis. These results suggest that Arl13b have important roles in bone formation and mechanosensation.
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Affiliation(s)
- Tingting Lin
- Department of Implantology, Stomatological Hospital and Dental School of Tongji University, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, Shanghai 200072, China
| | - Yao Sun
- Department of Implantology, Stomatological Hospital and Dental School of Tongji University, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, Shanghai 200072, China.
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10
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Liu YX, Li WJ, Zhang RK, Sun SN, Fan ZC. Unraveling the intricate cargo-BBSome coupling mechanism at the ciliary tip. Proc Natl Acad Sci U S A 2023; 120:e2218819120. [PMID: 36943875 PMCID: PMC10068815 DOI: 10.1073/pnas.2218819120] [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: 11/03/2022] [Accepted: 02/13/2023] [Indexed: 03/23/2023] Open
Abstract
Certain ciliary transmembrane and membrane-tethered signaling proteins migrate from the ciliary tip to base via retrograde intraflagellar transport (IFT), essential for maintaining their ciliary dynamics to enable cells to sense and transduce extracellular stimuli inside the cell. During this process, the BBSome functions as an adaptor between retrograde IFT trains and these signaling protein cargoes. The Arf-like 13 (ARL13) small GTPase resembles ARL6/BBS3 in facilitating these signaling cargoes to couple with the BBSome at the ciliary tip prior to loading onto retrograde IFT trains for transporting towards the ciliary base, while the molecular basis for how this intricate coupling event happens remains elusive. Here, we report that Chlamydomonas ARL13 only in a GTP-bound form (ARL13GTP) anchors to the membrane for diffusing into cilia. Upon entering cilia, ARL13 undergoes GTPase cycle for shuttling between the ciliary membrane (ARL13GTP) and matrix (ARL13GDP). To achieve this goal, the ciliary membrane-anchored BBS3GTP binds the ciliary matrix-residing ARL13GDP to activate the latter as an ARL13 guanine nucleotide exchange factor. At the ciliary tip, ARL13GTP recruits the ciliary matrix-residing and post-remodeled BBSome as an ARL13 effector to anchor to the ciliary membrane. This makes the BBSome spatiotemporally become available for the ciliary membrane-tethered phospholipase D (PLD) to couple with. Afterward, ARL13GTP hydrolyzes GTP for releasing the PLD-laden BBSome to load onto retrograde IFT trains. According to this model, hedgehog signaling defects associated with ARL13b and BBS3 mutations in humans could be satisfactorily explained, providing us a mechanistic understanding behind BBSome-cargo coupling required for proper ciliary signaling.
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Affiliation(s)
- Yan-Xia Liu
- State Key Laboratory of Food Nutrition and Safety, Institute of Health Biotechnology, Tianjin University of Science and Technology, Tianjin300457, China
| | - Wen-Juan Li
- State Key Laboratory of Food Nutrition and Safety, Institute of Health Biotechnology, Tianjin University of Science and Technology, Tianjin300457, China
| | - Rui-Kai Zhang
- State Key Laboratory of Food Nutrition and Safety, Institute of Health Biotechnology, Tianjin University of Science and Technology, Tianjin300457, China
| | - Sheng-Nan Sun
- State Key Laboratory of Food Nutrition and Safety, Institute of Health Biotechnology, Tianjin University of Science and Technology, Tianjin300457, China
| | - Zhen-Chuan Fan
- State Key Laboratory of Food Nutrition and Safety, Institute of Health Biotechnology, Tianjin University of Science and Technology, Tianjin300457, China
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11
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Liang X, Yadav SP, Batz ZA, Nellissery J, Swaroop A. Protein kinase CK2 modulates the activity of Maf-family bZIP transcription factor NRL in rod photoreceptors of mammalian retina. Hum Mol Genet 2023; 32:948-958. [PMID: 36226585 PMCID: PMC9991000 DOI: 10.1093/hmg/ddac256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 09/21/2022] [Accepted: 10/07/2022] [Indexed: 11/14/2022] Open
Abstract
Maf-family basic motif leucine zipper protein NRL specifies rod photoreceptor cell fate during retinal development and, in concert with homeodomain protein CRX and other regulatory factors, controls the expression of most rod-expressed genes including the visual pigment gene Rhodopsin (Rho). Transcriptional regulatory activity of NRL is modulated by post-translational modifications, especially phosphorylation, and mutations at specific phosphosites can lead to retinal degeneration. During our studies to elucidate NRL-mediated transcriptional regulation, we identified protein kinase CK2 in NRL-enriched complexes bound to Rho promoter-enhancer regions and in NRL-enriched high molecular mass fractions from the bovine retina. The presence of CK2 in NRL complexes was confirmed by co-immunoprecipitation from developing and adult mouse retinal extracts. In vitro kinase assay and bioinformatic analysis indicated phosphorylation of NRL at Ser117 residue by CK2. Co-transfection of Csnk2a1 cDNA encoding murine CK2 with human NRL and CRX reduced the bovine Rho promoter-driven luciferase expression in HEK293 cells and mutagenesis of NRL-Ser117 residue to Ala restored the reporter gene activity. In concordance, overexpression of CK2 in the mouse retina in vivo by electroporation resulted in reduction of Rho promoter-driven DsRed reporter expression as well as the transcript level of many phototransduction genes. Thus, our studies demonstrate that CK2 can phosphorylate Ser117 of NRL. Modulation of NRL activity by CK2 suggests intricate interdependence of transcriptional and signaling pathways in maintaining rod homeostasis.
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Affiliation(s)
- Xulong Liang
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, 6 Center Drive, MSC0610, Bethesda, MD 20892, USA
| | - Sharda P Yadav
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, 6 Center Drive, MSC0610, Bethesda, MD 20892, USA
| | - Zachary A Batz
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, 6 Center Drive, MSC0610, Bethesda, MD 20892, USA
| | - Jacob Nellissery
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, 6 Center Drive, MSC0610, Bethesda, MD 20892, USA
| | - Anand Swaroop
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, 6 Center Drive, MSC0610, Bethesda, MD 20892, USA
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12
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Palicharla VR, Hwang SH, Somatilaka BN, Legué E, Shimada IS, Familiari NE, Tran VM, Woodruff JB, Liem KF, Mukhopadhyay S. Interactions between TULP3 tubby domain and ARL13B amphipathic helix promote lipidated protein transport to cilia. Mol Biol Cell 2023; 34:ar18. [PMID: 36652335 PMCID: PMC10011728 DOI: 10.1091/mbc.e22-10-0473] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The primary cilium is a nexus for cell signaling and relies on specific protein trafficking for function. The tubby family protein TULP3 transports integral membrane proteins into cilia through interactions with the intraflagellar transport complex-A (IFT-A) and phosphoinositides. It was previously shown that short motifs called ciliary localization sequences (CLSs) are necessary and sufficient for TULP3-dependent ciliary trafficking of transmembrane cargoes. However, the mechanisms by which TULP3 regulates ciliary compartmentalization of nonintegral, membrane-associated proteins and whether such trafficking requires TULP3-dependent CLSs is unknown. Here we show that TULP3 is required for ciliary transport of the Joubert syndrome-linked palmitoylated GTPase ARL13B through a CLS. An N-terminal amphipathic helix, preceding the GTPase domain of ARL13B, couples with the TULP3 tubby domain for ciliary trafficking, irrespective of palmitoylation. ARL13B transport requires TULP3 binding to IFT-A but not to phosphoinositides, indicating strong membrane-proximate interactions, unlike transmembrane cargo transport requiring both properties of TULP3. TULP3-mediated trafficking of ARL13B also regulates ciliary enrichment of farnesylated and myristoylated downstream effectors of ARL13B. The lipidated cargoes show distinctive depletion kinetics from kidney epithelial cilia with relation to Tulp3 deletion-induced renal cystogenesis. Overall, these findings indicate an expanded role of the tubby domain in capturing analogous helical secondary structural motifs from diverse cargoes.
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Affiliation(s)
- Vivek Reddy Palicharla
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Sun-Hee Hwang
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | | | - Emilie Legué
- Vertebrate Developmental Biology Program, Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06520
| | - Issei S Shimada
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Nicole E Familiari
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Vanna M Tran
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Jeffrey B Woodruff
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Karel F Liem
- Vertebrate Developmental Biology Program, Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06520
| | - Saikat Mukhopadhyay
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
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13
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Mahbub L, Kozlov G, Zong P, Tetteh S, Nethramangalath T, Knorn C, Jiang J, Shahsavan A, Lee E, Yue L, Runnels LW, Gehring K. Structural insights into regulation of TRPM7 divalent cation uptake by the small GTPase ARL15. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.19.524765. [PMID: 36711628 PMCID: PMC9882303 DOI: 10.1101/2023.01.19.524765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Cystathionine-β-synthase (CBS)-pair domain divalent metal cation transport mediators (CNNMs) are an evolutionarily conserved family of magnesium transporters. They promote efflux of Mg 2+ ions on their own or uptake of divalent cations when coupled to the transient receptor potential ion channel subfamily M member 7 (TRPM7). Recently, ADP-ribosylation factor-like GTPase 15 (ARL15) has been identified as CNNM binding partner and an inhibitor of divalent cation influx by TRPM7. Here, we characterize ARL15 as a GTP-binding protein and demonstrate that it binds the CNNM CBS-pair domain with low micromolar affinity. The crystal structure of the complex between ARL15 GTPase domain and CNNM2 CBS-pair domain reveals the molecular determinants of the interaction and allowed the identification of mutations in ARL15 and CNNM2 mutations that abrogate binding. Loss of CNNM binding prevented ARL15 suppression of TRPM7 channel activity in support of previous reports that the proteins function as a ternary complex. Binding experiments with phosphatase of regenerating liver 2 (PRL2 or PTP4A2) revealed that ARL15 and PRLs compete for binding CNNM, suggesting antagonistic regulation of divalent cation transport by the two proteins.
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Affiliation(s)
- Luba Mahbub
- Department of Biochemistry, McGill University, Montréal, Canada,Centre de recherche en biologie structurale, McGill University, Montréal, Canada
| | - Guennadi Kozlov
- Department of Biochemistry, McGill University, Montréal, Canada,Centre de recherche en biologie structurale, McGill University, Montréal, Canada
| | - Pengyu Zong
- Dept. of Cell Biology. UCONN Health Center, Farmington, Connecticut, United States
| | - Sandra Tetteh
- Rutgers-Robert Wood Johnson Medical School, Piscataway, New Jersey, United States
| | | | - Caroline Knorn
- Department of Biochemistry, McGill University, Montréal, Canada,Centre de recherche en biologie structurale, McGill University, Montréal, Canada
| | - Jianning Jiang
- Department of Biochemistry, McGill University, Montréal, Canada,Centre de recherche en biologie structurale, McGill University, Montréal, Canada
| | - Ashkan Shahsavan
- Department of Biochemistry, McGill University, Montréal, Canada,Centre de recherche en biologie structurale, McGill University, Montréal, Canada
| | - Emma Lee
- Department of Biochemistry, McGill University, Montréal, Canada,Centre de recherche en biologie structurale, McGill University, Montréal, Canada
| | - Lixia Yue
- Dept. of Cell Biology. UCONN Health Center, Farmington, Connecticut, United States
| | - Loren W. Runnels
- Rutgers-Robert Wood Johnson Medical School, Piscataway, New Jersey, United States
| | - Kalle Gehring
- Department of Biochemistry, McGill University, Montréal, Canada,Centre de recherche en biologie structurale, McGill University, Montréal, Canada,Corresponding author:
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14
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Zhao H, Khan Z, Westlake CJ. Ciliogenesis membrane dynamics and organization. Semin Cell Dev Biol 2023; 133:20-31. [PMID: 35351373 PMCID: PMC9510604 DOI: 10.1016/j.semcdb.2022.03.021] [Citation(s) in RCA: 26] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 03/17/2022] [Accepted: 03/18/2022] [Indexed: 12/28/2022]
Abstract
Ciliogenesis is a complex multistep process used to describe assembly of cilia and flagella. These organelles play essential roles in motility and signaling on the surface of cells. Cilia are built at the distal ends of centrioles through the formation of an axoneme that is surrounded by the ciliary membrane. As is the case in the biogenesis of other cellular organelles, regulators of membrane trafficking play essential roles in ciliogenesis, albeit with a unique feature that membranes are organized around microtubule-based structures. Membrane association with the distal end of the centriole is a critical initiating step for ciliogenesis. Studies of this process in different cell types suggests that a singular mechanism may not be utilized to initiate cilium assembly. In this review, we focus on recent insights into cilium biogenesis and the roles membrane trafficking regulators play in described ciliogenesis mechanisms with relevance to human disease.
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Affiliation(s)
- Huijie Zhao
- Center for Cancer Research, NCI Frederick, Laboratory of Cellular and Developmental, Signaling, Frederick, MD 21702, USA
| | - Ziam Khan
- Center for Cancer Research, NCI Frederick, Laboratory of Cellular and Developmental, Signaling, Frederick, MD 21702, USA
| | - Christopher J Westlake
- Center for Cancer Research, NCI Frederick, Laboratory of Cellular and Developmental, Signaling, Frederick, MD 21702, USA.
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15
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Cilleros-Rodriguez D, Martin-Morales R, Barbeito P, Deb Roy A, Loukil A, Sierra-Rodero B, Herranz G, Pampliega O, Redrejo-Rodriguez M, Goetz SC, Izquierdo M, Inoue T, Garcia-Gonzalo FR. Multiple ciliary localization signals control INPP5E ciliary targeting. eLife 2022; 11:78383. [PMID: 36063381 PMCID: PMC9444247 DOI: 10.7554/elife.78383] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 08/21/2022] [Indexed: 12/04/2022] Open
Abstract
Primary cilia are sensory membrane protrusions whose dysfunction causes ciliopathies. INPP5E is a ciliary phosphoinositide phosphatase mutated in ciliopathies like Joubert syndrome. INPP5E regulates numerous ciliary functions, but how it accumulates in cilia remains poorly understood. Herein, we show INPP5E ciliary targeting requires its folded catalytic domain and is controlled by four conserved ciliary localization signals (CLSs): LLxPIR motif (CLS1), W383 (CLS2), FDRxLYL motif (CLS3) and CaaX box (CLS4). We answer two long-standing questions in the field. First, partial CLS1-CLS4 redundancy explains why CLS4 is dispensable for ciliary targeting. Second, the essential need for CLS2 clarifies why CLS3-CLS4 are together insufficient for ciliary accumulation. Furthermore, we reveal that some Joubert syndrome mutations perturb INPP5E ciliary targeting, and clarify how each CLS works: (i) CLS4 recruits PDE6D, RPGR and ARL13B, (ii) CLS2-CLS3 regulate association to TULP3, ARL13B, and CEP164, and (iii) CLS1 and CLS4 cooperate in ATG16L1 binding. Altogether, we shed light on the mechanisms of INPP5E ciliary targeting, revealing a complexity without known parallels among ciliary cargoes.
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Affiliation(s)
- Dario Cilleros-Rodriguez
- Departamento de Bioquímica, Facultad de Medicina, Universidad Autónoma de Madrid (UAM), Madrid, Spain.,Instituto de Investigaciones Biomédicas "Alberto Sols" (IIBM), Consejo Superior de Investigaciones Científicas (CSIC)-UAM, Madrid, Spain.,Instituto de Investigación del Hospital Universitario de La Paz (IdiPAZ), Madrid, Spain.,CIBER de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| | - Raquel Martin-Morales
- Departamento de Bioquímica, Facultad de Medicina, Universidad Autónoma de Madrid (UAM), Madrid, Spain.,Instituto de Investigaciones Biomédicas "Alberto Sols" (IIBM), Consejo Superior de Investigaciones Científicas (CSIC)-UAM, Madrid, Spain.,Instituto de Investigación del Hospital Universitario de La Paz (IdiPAZ), Madrid, Spain.,CIBER de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| | - Pablo Barbeito
- Departamento de Bioquímica, Facultad de Medicina, Universidad Autónoma de Madrid (UAM), Madrid, Spain.,Instituto de Investigaciones Biomédicas "Alberto Sols" (IIBM), Consejo Superior de Investigaciones Científicas (CSIC)-UAM, Madrid, Spain.,Instituto de Investigación del Hospital Universitario de La Paz (IdiPAZ), Madrid, Spain.,CIBER de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| | - Abhijit Deb Roy
- Department of Cell Biology, Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Abdelhalim Loukil
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, United States
| | - Belen Sierra-Rodero
- Departamento de Bioquímica, Facultad de Medicina, Universidad Autónoma de Madrid (UAM), Madrid, Spain.,Instituto de Investigaciones Biomédicas "Alberto Sols" (IIBM), Consejo Superior de Investigaciones Científicas (CSIC)-UAM, Madrid, Spain.,Instituto de Investigación del Hospital Universitario de La Paz (IdiPAZ), Madrid, Spain.,CIBER de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| | - Gonzalo Herranz
- Departamento de Bioquímica, Facultad de Medicina, Universidad Autónoma de Madrid (UAM), Madrid, Spain.,Instituto de Investigaciones Biomédicas "Alberto Sols" (IIBM), Consejo Superior de Investigaciones Científicas (CSIC)-UAM, Madrid, Spain
| | - Olatz Pampliega
- Department of Neurosciences, University of the Basque Country, Achucarro Basque Center for Neuroscience-UPV/EHU, Leioa, Spain
| | - Modesto Redrejo-Rodriguez
- Departamento de Bioquímica, Facultad de Medicina, Universidad Autónoma de Madrid (UAM), Madrid, Spain.,Instituto de Investigaciones Biomédicas "Alberto Sols" (IIBM), Consejo Superior de Investigaciones Científicas (CSIC)-UAM, Madrid, Spain
| | - Sarah C Goetz
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, United States
| | - Manuel Izquierdo
- Departamento de Bioquímica, Facultad de Medicina, Universidad Autónoma de Madrid (UAM), Madrid, Spain.,Instituto de Investigaciones Biomédicas "Alberto Sols" (IIBM), Consejo Superior de Investigaciones Científicas (CSIC)-UAM, Madrid, Spain
| | - Takanari Inoue
- Department of Cell Biology, Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Francesc R Garcia-Gonzalo
- Departamento de Bioquímica, Facultad de Medicina, Universidad Autónoma de Madrid (UAM), Madrid, Spain.,Instituto de Investigaciones Biomédicas "Alberto Sols" (IIBM), Consejo Superior de Investigaciones Científicas (CSIC)-UAM, Madrid, Spain.,Instituto de Investigación del Hospital Universitario de La Paz (IdiPAZ), Madrid, Spain.,CIBER de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
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16
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Dai J, Zhang G, Alkhofash RA, Mekonnen B, Saravanan S, Xue B, Fan ZC, Betleja E, Cole DG, Liu P, Lechtreck K. Loss of ARL13 impedes BBSome-dependent cargo export from Chlamydomonas cilia. J Cell Biol 2022; 221:213429. [PMID: 36040375 PMCID: PMC9436004 DOI: 10.1083/jcb.202201050] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 05/12/2022] [Accepted: 07/11/2022] [Indexed: 12/25/2022] Open
Abstract
The GTPase Arl13b participates in ciliary protein transport, but its contribution to intraflagellar transport (IFT), the main motor-based protein shuttle of cilia, remains largely unknown. Chlamydomonas arl13 mutant cilia were characterized by both abnormal reduction and accumulation of select membrane-associated proteins. With respect to the latter, a similar set of proteins including phospholipase D (PLD) also accumulated in BBSome-deficient cilia. IFT and BBSome traffic were apparently normal in arl13. However, transport of PLD, which in control cells moves by BBSome-dependent IFT, was impaired in arl13, causing PLD to accumulate in cilia. ARL13 only rarely and transiently traveled by IFT, indicating that it is not a co-migrating adapter securing PLD to IFT trains. In conclusion, the loss of Chlamydomonas ARL13 impedes BBSome-dependent protein transport, resulting in overlapping biochemical defects in arl13 and bbs mutant cilia.
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Affiliation(s)
- Jin Dai
- Cellular Biology, University of Georgia, Athens, GA
| | - Gui Zhang
- Cellular Biology, University of Georgia, Athens, GA
| | | | | | | | - Bin Xue
- State Key Laboratory of Food Nutrition and Safety, Institute of Health Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Zhen-Chuan Fan
- State Key Laboratory of Food Nutrition and Safety, Institute of Health Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | | | | | - Peiwei Liu
- College of Life Science, Shandong Normal University, Jinan, Shandong, China
| | - Karl Lechtreck
- Cellular Biology, University of Georgia, Athens, GA,Correspondence to Karl F. Lechtreck:
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17
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Walker RV, Maranto A, Palicharla VR, Hwang SH, Mukhopadhyay S, Qian F. Cilia-Localized Counterregulatory Signals as Drivers of Renal Cystogenesis. Front Mol Biosci 2022; 9:936070. [PMID: 35832738 PMCID: PMC9272769 DOI: 10.3389/fmolb.2022.936070] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 05/30/2022] [Indexed: 12/18/2022] Open
Abstract
Primary cilia play counterregulatory roles in cystogenesis-they inhibit cyst formation in the normal renal tubule but promote cyst growth when the function of polycystins is impaired. Key upstream cilia-specific signals and components involved in driving cystogenesis have remained elusive. Recent studies of the tubby family protein, Tubby-like protein 3 (TULP3), have provided new insights into the cilia-localized mechanisms that determine cyst growth. TULP3 is a key adapter of the intraflagellar transport complex A (IFT-A) in the trafficking of multiple proteins specifically into the ciliary membrane. Loss of TULP3 results in the selective exclusion of its cargoes from cilia without affecting their extraciliary pools and without disrupting cilia or IFT-A complex integrity. Epistasis analyses have indicated that TULP3 inhibits cystogenesis independently of the polycystins during kidney development but promotes cystogenesis in adults when polycystins are lacking. In this review, we discuss the current model of the cilia-dependent cyst activation (CDCA) mechanism in autosomal dominant polycystic kidney disease (ADPKD) and consider the possible roles of ciliary and extraciliary polycystins in regulating CDCA. We then describe the limitations of this model in not fully accounting for how cilia single knockouts cause significant cystic changes either in the presence or absence of polycystins. Based on available data from TULP3/IFT-A-mediated differential regulation of cystogenesis in kidneys with deletion of polycystins either during development or in adulthood, we hypothesize the existence of cilia-localized components of CDCA (cCDCA) and cilia-localized cyst inhibition (CLCI) signals. We develop the criteria for cCDCA/CLCI signals and discuss potential TULP3 cargoes as possible cilia-localized components that determine cystogenesis in kidneys during development and in adult mice.
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Affiliation(s)
- Rebecca V. Walker
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Anthony Maranto
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
| | | | - Sun-Hee Hwang
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX, United States
| | - Saikat Mukhopadhyay
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX, United States
| | - Feng Qian
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
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18
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Dutta P, Ray K. Ciliary membrane, localised lipid modification and cilia function. J Cell Physiol 2022; 237:2613-2631. [PMID: 35661356 DOI: 10.1002/jcp.30787] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 05/06/2022] [Accepted: 05/11/2022] [Indexed: 11/08/2022]
Abstract
Cilium, a tiny microtubule-based cellular appendage critical for cell signalling and physiology, displays a large variety of receptors. The composition and turnover of ciliary lipids and receptors determine cell behaviour. Due to the exclusion of ribosomal machinery and limited membrane area, a cilium needs adaptive logistics to actively reconstitute the lipid and receptor compositions during development and differentiation. How is this dynamicity generated? Here, we examine whether, along with the Intraflagellar-Transport, targeted changes in sector-wise lipid composition could control the receptor localisation and functions in the cilia. We discuss how an interplay between ciliary lipid composition, localised lipid modification, and receptor function could contribute to cilia growth and signalling. We argue that lipid modification at the cell-cilium interface could generate an added thrust for a selective exchange of membrane lipids and the transmembrane and membrane-associated proteins.
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Affiliation(s)
- Priya Dutta
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
| | - Krishanu Ray
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
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19
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Dewees SI, Vargová R, Hardin KR, Turn RE, Devi S, Linnert J, Wolfrum U, Caspary T, Eliáš M, Kahn RA. Phylogenetic profiling and cellular analyses of ARL16 reveal roles in traffic of IFT140 and INPP5E. Mol Biol Cell 2022; 33:ar33. [PMID: 35196065 PMCID: PMC9250359 DOI: 10.1091/mbc.e21-10-0509-t] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 01/11/2022] [Accepted: 02/18/2022] [Indexed: 12/14/2022] Open
Abstract
The ARF family of regulatory GTPases is ancient, with 16 members predicted to have been present in the last eukaryotic common ancestor. Our phylogenetic profiling of paralogues in diverse species identified four family members whose presence correlates with that of a cilium/flagellum: ARL3, ARL6, ARL13, and ARL16. No prior evidence links ARL16 to cilia or other cell functions, despite its presence throughout eukaryotes. Deletion of ARL16 in mouse embryonic fibroblasts (MEFs) results in decreased ciliogenesis yet increased ciliary length. We also found Arl16 knockout (KO) in MEFs to alter ciliary protein content, including loss of ARL13B, ARL3, INPP5E, and the IFT-A core component IFT140. Instead, both INPP5E and IFT140 accumulate at the Golgi in Arl16 KO lines, while other intraflagellar transport (IFT) proteins do not, suggesting a specific defect in traffic from Golgi to cilia. We propose that ARL16 regulates a Golgi-cilia traffic pathway and is required specifically in the export of IFT140 and INPP5E from the Golgi.
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Affiliation(s)
- Skylar I. Dewees
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
- Biochemistry, Cell & Developmental Biology Graduate Program, Laney Graduate School, Emory University, Atlanta, GA 30307
| | - Romana Vargová
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, CZ-710 00, Ostrava, Czech Republic
| | - Katherine R. Hardin
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322
- Biochemistry, Cell & Developmental Biology Graduate Program, Laney Graduate School, Emory University, Atlanta, GA 30307
| | - Rachel E. Turn
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
- Biochemistry, Cell & Developmental Biology Graduate Program, Laney Graduate School, Emory University, Atlanta, GA 30307
- Department of Microbiology and Immunology, Stanford University, Palo Alto, CA 94305-5124
| | - Saroja Devi
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
| | - Joshua Linnert
- Institute of Molecular Physiology, Johannes Gutenberg University, Mainz 55128, Germany
| | - Uwe Wolfrum
- Institute of Molecular Physiology, Johannes Gutenberg University, Mainz 55128, Germany
| | - Tamara Caspary
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322
| | - Marek Eliáš
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, CZ-710 00, Ostrava, Czech Republic
| | - Richard A. Kahn
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
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20
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Turn RE, Hu Y, Dewees SI, Devi N, East MP, Hardin KR, Khatib T, Linnert J, Wolfrum U, Lim MJ, Casanova JE, Caspary T, Kahn RA. The ARF GAPs ELMOD1 and ELMOD3 act at the Golgi and cilia to regulate ciliogenesis and ciliary protein traffic. Mol Biol Cell 2022; 33:ar13. [PMID: 34818063 PMCID: PMC9236152 DOI: 10.1091/mbc.e21-09-0443] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 11/16/2021] [Accepted: 11/19/2021] [Indexed: 11/11/2022] Open
Abstract
ELMODs are a family of three mammalian paralogues that display GTPase-activating protein (GAP) activity toward a uniquely broad array of ADP-ribosylation factor (ARF) family GTPases that includes ARF-like (ARL) proteins. ELMODs are ubiquitously expressed in mammalian tissues, highly conserved across eukaryotes, and ancient in origin, being present in the last eukaryotic common ancestor. We described functions of ELMOD2 in immortalized mouse embryonic fibroblasts (MEFs) in the regulation of cell division, microtubules, ciliogenesis, and mitochondrial fusion. Here, using similar strategies with the paralogues ELMOD1 and ELMOD3, we identify novel functions and locations of these cell regulators and compare them to those of ELMOD2, allowing the determination of functional redundancy among the family members. We found strong similarities in phenotypes resulting from deletion of either Elmod1 or Elmod3 and marked differences from those arising in Elmod2 deletion lines. Deletion of either Elmod1 or Elmod3 results in the decreased ability of cells to form primary cilia, loss of a subset of proteins from cilia, and accumulation of some ciliary proteins at the Golgi, predicted to result from compromised traffic from the Golgi to cilia. These phenotypes are reversed upon activating mutant expression of either ARL3 or ARL16, linking their roles to ELMOD1/3 actions.
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Affiliation(s)
- Rachel E. Turn
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
- Biochemistry, Cell & Developmental Biology Graduate Program, Emory University, Atlanta, GA 30322
- Department of Microbiology and Immunology, Stanford University, Palo Alto, CA 94305
| | - Yihan Hu
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
- Department of Otolaryngology, Xiangya Hospital, Central South University, Changsha, 410008 Hunan, China
| | - Skylar I. Dewees
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
- Biochemistry, Cell & Developmental Biology Graduate Program, Emory University, Atlanta, GA 30322
| | - Narra Devi
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
| | - Michael P. East
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Katherine R. Hardin
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322
- Biochemistry, Cell & Developmental Biology Graduate Program, Emory University, Atlanta, GA 30322
| | - Tala Khatib
- Department of Hematology and Medical Oncology, Emory University School of Medicine, Atlanta, GA 30322
- Biochemistry, Cell & Developmental Biology Graduate Program, Emory University, Atlanta, GA 30322
| | - Joshua Linnert
- Institute of Molecular Physiology, Johannes Gutenberg University, Mainz 55128, Germany
| | - Uwe Wolfrum
- Institute of Molecular Physiology, Johannes Gutenberg University, Mainz 55128, Germany
| | - Michael J. Lim
- Department of Cell Biology, University of Virginia, Charlottesville, VA 22908
| | - James E. Casanova
- Department of Cell Biology, University of Virginia, Charlottesville, VA 22908
| | - Tamara Caspary
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322
| | - Richard A. Kahn
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
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21
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Fujisawa S, Qiu H, Nozaki S, Chiba S, Katoh Y, Nakayama K. ARL3 and ARL13B GTPases participate in distinct steps of INPP5E targeting to the ciliary membrane. Biol Open 2021; 10:bio058843. [PMID: 34447983 PMCID: PMC8496693 DOI: 10.1242/bio.058843] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 08/19/2021] [Indexed: 01/02/2023] Open
Abstract
INPP5E, a phosphoinositide 5-phosphatase, localizes on the ciliary membrane via its C-terminal prenyl moiety, and maintains the distinct ciliary phosphoinositide composition. The ARL3 GTPase contributes to the ciliary membrane localization of INPP5E by stimulating the release of PDE6D bound to prenylated INPP5E. Another GTPase, ARL13B, which is localized on the ciliary membrane, contributes to the ciliary membrane retention of INPP5E by directly binding to its ciliary targeting sequence. However, as ARL13B was shown to act as a guanine nucleotide exchange factor (GEF) for ARL3, it is also possible that ARL13B indirectly mediates the ciliary INPP5E localization via activating ARL3. We here show that INPP5E is delocalized from cilia in both ARL3-knockout (KO) and ARL13B-KO cells. However, some of the abnormal phenotypes were different between these KO cells, while others were found to be common, indicating the parallel roles of ARL3 and ARL13B, at least concerning some cellular functions. For several variants of ARL13B, their ability to interact with INPP5E, rather than their ability as an ARL3-GEF, was associated with whether they could rescue the ciliary localization of INPP5E in ARL13B-KO cells. These observations together indicate that ARL13B determines the ciliary localization of INPP5E, mainly by its direct binding to INPP5E.
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Affiliation(s)
- Sayaka Fujisawa
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Hantian Qiu
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Shohei Nozaki
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Shuhei Chiba
- Department of Genetic Disease Research, Graduate School of Medicine, Osaka City University, Abeno-ku, Osaka 545-8585, Japan
| | - Yohei Katoh
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Kazuhisa Nakayama
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
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22
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Vargová R, Wideman JG, Derelle R, Klimeš V, Kahn RA, Dacks JB, Eliáš M. A Eukaryote-Wide Perspective on the Diversity and Evolution of the ARF GTPase Protein Family. Genome Biol Evol 2021; 13:6319025. [PMID: 34247240 PMCID: PMC8358228 DOI: 10.1093/gbe/evab157] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/02/2021] [Indexed: 12/21/2022] Open
Abstract
The evolution of eukaryotic cellular complexity is interwoven with the extensive diversification of many protein families. One key family is the ARF GTPases that act in eukaryote-specific processes, including membrane traffic, tubulin assembly, actin dynamics, and cilia-related functions. Unfortunately, our understanding of the evolution of this family is limited. Sampling an extensive set of available genome and transcriptome sequences, we have assembled a data set of over 2,000 manually curated ARF family genes from 114 eukaryotic species, including many deeply diverged protist lineages, and carried out comprehensive molecular phylogenetic analyses. These reconstructed as many as 16 ARF family members present in the last eukaryotic common ancestor, nearly doubling the previously inferred ancient system complexity. Evidence for the wide occurrence and ancestral origin of Arf6, Arl13, and Arl16 is presented for the first time. Moreover, Arl17, Arl18, and SarB, newly described here, are absent from well-studied model organisms and as a result their function(s) remain unknown. Analyses of our data set revealed a previously unsuspected diversity of membrane association modes and domain architectures within the ARF family. We detail the step-wise expansion of the ARF family in the metazoan lineage, including discovery of several new animal-specific family members. Delving back to its earliest evolution in eukaryotes, the resolved relationship observed between the ARF family paralogs sets boundaries for scenarios of vesicle coat origins during eukaryogenesis. Altogether, our work fundamentally broadens the understanding of the diversity and evolution of a protein family underpinning the structural and functional complexity of the eukaryote cells.
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Affiliation(s)
- Romana Vargová
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Czech Republic
| | - Jeremy G Wideman
- Biodesign Center for Mechanisms of Evolution, School of Life Sciences, Arizona State University, Tempe, Arizona, USA
| | - Romain Derelle
- Station d'Ecologie Théorique et Expérimentale, UMR CNRS 5321, Moulis, France
| | - Vladimír Klimeš
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Czech Republic
| | - Richard A Kahn
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Joel B Dacks
- Division of Infectious Disease, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada.,Centre for Life's Origin and Evolution, Department of Genetics, Evolution and Environment, University College of London, United Kingdom
| | - Marek Eliáš
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Czech Republic
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23
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Suciu SK, Long AB, Caspary T. Smoothened and ARL13B are critical in mouse for superior cerebellar peduncle targeting. Genetics 2021; 218:6300527. [PMID: 34132778 PMCID: PMC8864748 DOI: 10.1093/genetics/iyab084] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 06/15/2021] [Indexed: 01/07/2023] Open
Abstract
Patients with the ciliopathy Joubert syndrome present with physical anomalies, intellectual disability, and a hindbrain malformation described as the "molar tooth sign" due to its appearance on an MRI. This radiological abnormality results from a combination of hypoplasia of the cerebellar vermis and inappropriate targeting of the white matter tracts of the superior cerebellar peduncles. ARL13B is a cilia-enriched regulatory GTPase established to regulate cell fate, cell proliferation, and axon guidance through vertebrate Hedgehog signaling. In patients, mutations in ARL13B cause Joubert syndrome. To understand the etiology of the molar tooth sign, we used mouse models to investigate the role of ARL13B during cerebellar development. We found that ARL13B regulates superior cerebellar peduncle targeting and these fiber tracts require Hedgehog signaling for proper guidance. However, in mouse, the Joubert-causing R79Q mutation in ARL13B does not disrupt Hedgehog signaling nor does it impact tract targeting. We found a small cerebellar vermis in mice lacking ARL13B function but no cerebellar vermis hypoplasia in mice expressing the Joubert-causing R79Q mutation. In addition, mice expressing a cilia-excluded variant of ARL13B that transduces Hedgehog normally showed normal tract targeting and vermis width. Taken together, our data indicate that ARL13B is critical for the control of cerebellar vermis width as well as superior cerebellar peduncle axon guidance, likely via Hedgehog signaling. Thus, our work highlights the complexity of ARL13B in molar tooth sign etiology.
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Affiliation(s)
- Sarah K Suciu
- Genetics and Molecular Biology Graduate Program, Emory University, Atlanta, GA 30322, USA,Department of Human Genetics, Emory University, Atlanta, GA 30322, USA
| | - Alyssa B Long
- Department of Human Genetics, Emory University, Atlanta, GA 30322, USA
| | - Tamara Caspary
- Department of Human Genetics, Emory University, Atlanta, GA 30322, USA,Corresponding author: Department of Human Genetics, 615 Michael Street, Suite 301, Atlanta, GA 30322.
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24
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Qiu H, Fujisawa S, Nozaki S, Katoh Y, Nakayama K. Interaction of INPP5E with ARL13B is essential for its ciliary membrane retention but dispensable for its ciliary entry. Biol Open 2021; 10:bio057653. [PMID: 33372066 PMCID: PMC7860134 DOI: 10.1242/bio.057653] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 12/09/2020] [Indexed: 12/11/2022] Open
Abstract
Compositions of proteins and lipids within cilia and on the ciliary membrane are maintained to be distinct from those of the cytoplasm and plasma membrane, respectively, by the presence of the ciliary gate. INPP5E is a phosphoinositide 5-phosphatase that is localized on the ciliary membrane by anchorage via its C-terminal prenyl moiety. In addition, the ciliary membrane localization of INPP5E is determined by the small GTPase ARL13B. However, it remained unclear as to how ARL13B participates in the localization of INPP5E. We here show that wild-type INPP5E, INPP5E(WT), in ARL13B-knockout cells and an INPP5E mutant defective in ARL13B binding, INPP5E(ΔCTS), in control cells were unable to show steady-state localization on the ciliary membrane. However, not only INPP5E(WT) but also INPP5E(ΔCTS) was able to rescue the abnormal localization of ciliary proteins in INPP5E-knockout cells. Analysis using the chemically induced dimerization system demonstrated that INPP5E(WT) in ARL13B-knockout cells and INPP5E(ΔCTS) in control cells were able to enter cilia, but neither was retained on the ciliary membrane due to the lack of the INPP5E-ARL13B interaction. Thus, our data demonstrate that binding of INPP5E to ARL13B is essential for its steady-state localization on the ciliary membrane but is dispensable for its entry into cilia.
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Affiliation(s)
- Hantian Qiu
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Sayaka Fujisawa
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Shohei Nozaki
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Yohei Katoh
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Kazuhisa Nakayama
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
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25
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Partisani M, Baron CL, Ghossoub R, Fayad R, Pagnotta S, Abélanet S, Macia E, Brau F, Lacas-Gervais S, Benmerah A, Luton F, Franco M. EFA6A, an exchange factor for Arf6, regulates early steps in ciliogenesis. J Cell Sci 2021; 134:237326. [PMID: 33483367 DOI: 10.1242/jcs.249565] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 11/20/2020] [Indexed: 12/13/2022] Open
Abstract
Ciliogenesis is a coordinated process initiated by the recruitment and fusion of pre-ciliary vesicles at the distal appendages of the mother centriole through mechanisms that remain unclear. Here, we report that EFA6A (also known as PSD), an exchange factor for the small G protein Arf6, is involved in early stage of ciliogenesis by promoting the fusion of distal appendage vesicles forming the ciliary vesicle. EFA6A is present in the vicinity of the mother centriole before primary cilium assembly and prior to the arrival of Arl13B-containing vesicles. During ciliogenesis, EFA6A initially accumulates at the mother centriole and later colocalizes with Arl13B along the ciliary membrane. EFA6A depletion leads to the inhibition of ciliogenesis, the absence of centrosomal Rab8-positive structures and the accumulation of Arl13B-positive vesicles around the distal appendages. Our results uncover a novel fusion machinery, comprising EFA6A, Arf6 and Arl13B, that controls the coordinated fusion of ciliary vesicles docked at the distal appendages of the mother centriole.
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Affiliation(s)
- Mariagrazia Partisani
- Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), UMR 7275 CNRS-Université Côte d'Azur, 660, route des lucioles, 06560 Valbonne, France
| | - Carole L Baron
- Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), UMR 7275 CNRS-Université Côte d'Azur, 660, route des lucioles, 06560 Valbonne, France
| | - Rania Ghossoub
- Centre de Recherche en Cancérologie de Marseille (CRCM), Inserm, U1068-CNRS UMR7258, Aix-Marseille Université, Institut Paoli-Calmettes, 13009 Marseille, France
| | - Racha Fayad
- Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), UMR 7275 CNRS-Université Côte d'Azur, 660, route des lucioles, 06560 Valbonne, France
| | - Sophie Pagnotta
- Centre Commun de Microscopie Appliquée (CCMA), Université Côte d'Azur Parc Valrose, 06103 Nice cedex 2, France
| | - Sophie Abélanet
- Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), UMR 7275 CNRS-Université Côte d'Azur, 660, route des lucioles, 06560 Valbonne, France
| | - Eric Macia
- Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), UMR 7275 CNRS-Université Côte d'Azur, 660, route des lucioles, 06560 Valbonne, France
| | - Frédéric Brau
- Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), UMR 7275 CNRS-Université Côte d'Azur, 660, route des lucioles, 06560 Valbonne, France
| | - Sandra Lacas-Gervais
- Centre Commun de Microscopie Appliquée (CCMA), Université Côte d'Azur Parc Valrose, 06103 Nice cedex 2, France
| | - Alexandre Benmerah
- Université de Paris, Imagine Institute, Laboratory of Inherited Kidney Diseases, INSERM UMR 1163, F-75015, Paris, France
| | - Frédéric Luton
- Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), UMR 7275 CNRS-Université Côte d'Azur, 660, route des lucioles, 06560 Valbonne, France
| | - Michel Franco
- Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), UMR 7275 CNRS-Université Côte d'Azur, 660, route des lucioles, 06560 Valbonne, France
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26
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Fisher S, Kuna D, Caspary T, Kahn RA, Sztul E. ARF family GTPases with links to cilia. Am J Physiol Cell Physiol 2020; 319:C404-C418. [PMID: 32520609 PMCID: PMC7500214 DOI: 10.1152/ajpcell.00188.2020] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The ADP-ribosylation factor (ARF) superfamily of regulatory GTPases, including both the ARF and ARF-like (ARL) proteins, control a multitude of cellular functions, including aspects of vesicular traffic, lipid metabolism, mitochondrial architecture, the assembly and dynamics of the microtubule and actin cytoskeletons, and other pathways in cell biology. Considering their general utility, it is perhaps not surprising that increasingly ARF/ARLs have been found in connection to primary cilia. Here, we critically evaluate the current knowledge of the roles four ARF/ARLs (ARF4, ARL3, ARL6, ARL13B) play in cilia and highlight key missing information that would help move our understanding forward. Importantly, these GTPases are themselves regulated by guanine nucleotide exchange factors (GEFs) that activate them and by GTPase-activating proteins (GAPs) that act as both effectors and terminators of signaling. We believe that the identification of the GEFs and GAPs and better models of the actions of these GTPases and their regulators will provide a much deeper understanding and appreciation of the mechanisms that underly ciliary functions and the causes of a number of human ciliopathies.
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Affiliation(s)
- Skylar Fisher
- 1Department of Biochemistry, Emory University
School of Medicine, Atlanta,
Georgia
| | - Damian Kuna
- 2Department of Cell, Developmental and Integrative
Biology, University of Alabama at Birmingham,
Birmingham, Alabama
| | - Tamara Caspary
- 3Department of Human Genetics, Emory
University School of Medicine, Atlanta,
Georgia
| | - Richard A. Kahn
- 1Department of Biochemistry, Emory University
School of Medicine, Atlanta,
Georgia
| | - Elizabeth Sztul
- 2Department of Cell, Developmental and Integrative
Biology, University of Alabama at Birmingham,
Birmingham, Alabama
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27
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Jászai J, Thamm K, Karbanová J, Janich P, Fargeas CA, Huttner WB, Corbeil D. Prominins control ciliary length throughout the animal kingdom: New lessons from human prominin-1 and zebrafish prominin-3. J Biol Chem 2020; 295:6007-6022. [PMID: 32201384 DOI: 10.1074/jbc.ra119.011253] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 03/18/2020] [Indexed: 01/18/2023] Open
Abstract
Prominins (proms) are transmembrane glycoproteins conserved throughout the animal kingdom. They are associated with plasma membrane protrusions, such as primary cilia, as well as extracellular vesicles derived thereof. Primary cilia host numerous signaling pathways affected in diseases known as ciliopathies. Human PROM1 (CD133) is detected in both somatic and cancer stem cells and is also expressed in terminally differentiated epithelial and photoreceptor cells. Genetic mutations in the PROM1 gene result in retinal degeneration by impairing the proper formation of the outer segment of photoreceptors, a modified cilium. Here, we investigated the impact of proms on two distinct examples of ciliogenesis. First, we demonstrate that the overexpression of a dominant-negative mutant variant of human PROM1 (i.e. mutation Y819F/Y828F) significantly decreases ciliary length in Madin-Darby canine kidney cells. These results contrast strongly to the previously observed enhancing effect of WT PROM1 on ciliary length. Mechanistically, the mutation impeded the interaction of PROM1 with ADP-ribosylation factor-like protein 13B, a key regulator of ciliary length. Second, we observed that in vivo knockdown of prom3 in zebrafish alters the number and length of monocilia in the Kupffer's vesicle, resulting in molecular and anatomical defects in the left-right asymmetry. These distinct loss-of-function approaches in two biological systems reveal that prom proteins are critical for the integrity and function of cilia. Our data provide new insights into ciliogenesis and might be of particular interest for investigations of the etiologies of ciliopathies.
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Affiliation(s)
- József Jászai
- Tissue Engineering Laboratories, Biotechnology Center (BIOTEC) and Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Tatzberg 47-49, 01307 Dresden, Germany; Institute of Anatomy, Medizinische Fakultät der Technischen Universität Dresden, Fiedlerstrasse 42, 01307 Dresden, Germany.
| | - Kristina Thamm
- Tissue Engineering Laboratories, Biotechnology Center (BIOTEC) and Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Tatzberg 47-49, 01307 Dresden, Germany
| | - Jana Karbanová
- Tissue Engineering Laboratories, Biotechnology Center (BIOTEC) and Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Tatzberg 47-49, 01307 Dresden, Germany
| | - Peggy Janich
- Tissue Engineering Laboratories, Biotechnology Center (BIOTEC) and Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Tatzberg 47-49, 01307 Dresden, Germany
| | - Christine A Fargeas
- Tissue Engineering Laboratories, Biotechnology Center (BIOTEC) and Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Tatzberg 47-49, 01307 Dresden, Germany
| | - Wieland B Huttner
- Max-Planck-Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Denis Corbeil
- Tissue Engineering Laboratories, Biotechnology Center (BIOTEC) and Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Tatzberg 47-49, 01307 Dresden, Germany.
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28
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Establishing and regulating the composition of cilia for signal transduction. Nat Rev Mol Cell Biol 2020; 20:389-405. [PMID: 30948801 DOI: 10.1038/s41580-019-0116-4] [Citation(s) in RCA: 246] [Impact Index Per Article: 61.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The primary cilium is a hair-like surface-exposed organelle of the eukaryotic cell that decodes a variety of signals - such as odorants, light and Hedgehog morphogens - by altering the local concentrations and activities of signalling proteins. Signalling within the cilium is conveyed through a diverse array of second messengers, including conventional signalling molecules (such as cAMP) and some unusual intermediates (such as sterols). Diffusion barriers at the ciliary base establish the unique composition of this signalling compartment, and cilia adapt their proteome to signalling demands through regulated protein trafficking. Much progress has been made on the molecular understanding of regulated ciliary trafficking, which encompasses not only exchanges between the cilium and the rest of the cell but also the shedding of signalling factors into extracellular vesicles.
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29
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Sheikh SA, Sisk RA, Schiavon CR, Waryah YM, Usmani MA, Steel DH, Sayer JA, Narsani AK, Hufnagel RB, Riazuddin S, Kahn RA, Waryah AM, Ahmed ZM. Homozygous Variant in ARL3 Causes Autosomal Recessive Cone Rod Dystrophy. Invest Ophthalmol Vis Sci 2020; 60:4811-4819. [PMID: 31743939 PMCID: PMC6944245 DOI: 10.1167/iovs.19-27263] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Purpose Cone rod dystrophy (CRD) is a group of inherited retinopathies characterized by the loss of cone and rod photoreceptor cells, which results in poor vision. This study aims to clinically and genetically characterize the segregating CRD phenotype in two large, consanguineous Pakistani families. Methods Funduscopy, optical coherence tomography (OCT), electroretinography (ERG), color vision, and visual acuity assessments were performed to evaluate the retinal structure and function of the affected individuals. Exome sequencing was performed to identify the genetic cause of CRD. Furthermore, the mutation's effect was evaluated using purified, bacterially expressed ADP-ribosylation factor-like protein 3 (ARL3) and mammalian cells. Results Fundus photography and OCT imaging demonstrated features that were consistent with CRD, including bull's eye macular lesions, macular atrophy, and central photoreceptor thinning. ERG analysis demonstrated moderate to severe reduction primarily of photopic responses in all affected individuals, and scotopic responses show reduction in two affected individuals. The exome sequencing revealed a novel homozygous variant (c.296G>T) in ARL3, which is predicted to substitute an evolutionarily conserved arginine with isoleucine within the encoded protein GTP-binding domain (R99I). The functional studies on the bacterial and heterologous mammalian cells revealed that the arginine at position 99 is essential for the stability of ARL3. Conclusions Our study uncovers an additional CRD gene and assigns the CRD phenotype to a variant of ARL3. The results imply that cargo transportation in photoreceptors as mediated by the ARL3 pathway is essential for cone and rod cell survival and vision in humans.
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Affiliation(s)
- Shakeel A Sheikh
- Department of Otorhinolaryngology-Head and Neck Surgery, School of Medicine University of Maryland, Baltimore, Maryland, United States.,Molecular Biology & Genetics Department, Liaquat University of Medical & Health Sciences, Jamshoro, Pakistan
| | - Robert A Sisk
- Abrahamson Pediatric Eye Institute, Cincinnati Children's Hospital, Cincinnati, Ohio, United States.,Cincinnati Eye Institute, Cincinnati, Ohio, United States
| | - Cara R Schiavon
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, United States
| | - Yar M Waryah
- Molecular Biology & Genetics Department, Liaquat University of Medical & Health Sciences, Jamshoro, Pakistan
| | - Muhammad A Usmani
- Department of Otorhinolaryngology-Head and Neck Surgery, School of Medicine University of Maryland, Baltimore, Maryland, United States
| | - David H Steel
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Newcastle upon Tyne, United Kingdom
| | - John A Sayer
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Newcastle upon Tyne, United Kingdom
| | - Ashok K Narsani
- Institute of Ophthalmology, Liaquat University of Medical & Health Sciences, Jamshoro, Pakistan
| | - Robert B Hufnagel
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Saima Riazuddin
- Department of Otorhinolaryngology-Head and Neck Surgery, School of Medicine University of Maryland, Baltimore, Maryland, United States
| | - Richard A Kahn
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, United States
| | - Ali M Waryah
- Molecular Biology & Genetics Department, Liaquat University of Medical & Health Sciences, Jamshoro, Pakistan
| | - Zubair M Ahmed
- Department of Otorhinolaryngology-Head and Neck Surgery, School of Medicine University of Maryland, Baltimore, Maryland, United States
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30
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Gigante ED, Taylor MR, Ivanova AA, Kahn RA, Caspary T. ARL13B regulates Sonic hedgehog signaling from outside primary cilia. eLife 2020; 9:50434. [PMID: 32129762 PMCID: PMC7075693 DOI: 10.7554/elife.50434] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 02/25/2020] [Indexed: 01/13/2023] Open
Abstract
ARL13B is a regulatory GTPase highly enriched in cilia. Complete loss of Arl13b disrupts cilia architecture, protein trafficking and Sonic hedgehog signaling. To determine whether ARL13B is required within cilia, we knocked in a cilia-excluded variant of ARL13B (V358A) and showed it retains all known biochemical function. We found that ARL13BV358A protein was expressed but could not be detected in cilia, even when retrograde ciliary transport was blocked. We showed Arl13bV358A/V358A mice are viable and fertile with normal Shh signal transduction. However, in contrast to wild type cilia, Arl13bV358A/V358A cells displayed short cilia and lacked ciliary ARL3 and INPP5E. These data indicate that ARL13B's role within cilia can be uncoupled from its function outside of cilia. Furthermore, these data imply that the cilia defects upon complete absence of ARL13B do not underlie the alterations in Shh transduction, which is unexpected given the requirement of cilia for Shh transduction.
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Affiliation(s)
- Eduardo D Gigante
- Neuroscience Graduate Program, Emory University School of MedicineAtlantaUnited States,Department of Human Genetics, Emory University School of MedicineAtlantaUnited States
| | - Megan R Taylor
- Emory College of Arts and Sciences, Emory University School of MedicineAtlantaUnited States
| | - Anna A Ivanova
- Department of Biochemistry, Emory University School of MedicineAtlantaUnited States
| | - Richard A Kahn
- Department of Biochemistry, Emory University School of MedicineAtlantaUnited States
| | - Tamara Caspary
- Department of Human Genetics, Emory University School of MedicineAtlantaUnited States
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31
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Ishida M, Bonifacino JS. ARFRP1 functions upstream of ARL1 and ARL5 to coordinate recruitment of distinct tethering factors to the trans-Golgi network. J Cell Biol 2019; 218:3681-3696. [PMID: 31575603 PMCID: PMC6829661 DOI: 10.1083/jcb.201905097] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 08/09/2019] [Accepted: 08/27/2019] [Indexed: 12/22/2022] Open
Abstract
SNARE-mediated fusion of endosome-derived transport carriers with the trans-Golgi network (TGN) depends on the concerted action of two types of tethering factors: long coiled-coil tethers of the golgin family, and the heterotetrameric complex GARP. Whereas the golgins mediate long-distance capture of the carriers, GARP promotes assembly of the SNAREs. It remains to be determined, however, how the functions of these tethering factors are coordinated. Herein we report that the ARF-like (ARL) GTPase ARFRP1 functions upstream of two other ARL GTPases, ARL1 and ARL5, which in turn recruit golgins and GARP, respectively, to the TGN. We also show that this mechanism is essential for the delivery of retrograde cargos to the TGN. Our findings thus demonstrate that ARFRP1 is a master regulator of retrograde-carrier tethering to the TGN. The coordinated recruitment of distinct tethering factors by a bifurcated GTPase cascade may be paradigmatic of other vesicular fusion events within the cell.
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Affiliation(s)
- Morié Ishida
- Cell Biology and Neurobiology Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD
| | - Juan S Bonifacino
- Cell Biology and Neurobiology Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD
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Pipaliya SV, Schlacht A, Klinger CM, Kahn RA, Dacks J. Ancient complement and lineage-specific evolution of the Sec7 ARF GEF proteins in eukaryotes. Mol Biol Cell 2019; 30:1846-1863. [PMID: 31141460 PMCID: PMC6727740 DOI: 10.1091/mbc.e19-01-0073] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Guanine nucleotide exchange factors (GEFs) are the initiators of signaling by every regulatory GTPase, which in turn act to regulate a wide array of essential cellular processes. To date, each family of GTPases is activated by distinct families of GEFs. Bidirectional membrane trafficking is regulated by ADP-ribosylation factor (ARF) GTPases and the development throughout eukaryotic evolution of increasingly complex systems of such traffic required the acquisition of a functionally diverse cohort of ARF GEFs to control it. We performed phylogenetic analyses of ARF GEFs in eukaryotes, defined by the presence of the Sec7 domain, and found three subfamilies (BIG, GBF1, and cytohesins) to have been present in the ancestor of all eukaryotes. The four other subfamilies (EFA6/PSD, IQSEC7/BRAG, FBX8, and TBS) are opisthokont, holozoan, metazoan, and alveolate/haptophyte specific, respectively, and each is derived from cytohesins. We also identified a cytohesin-derived subfamily, termed ankyrin repeat-containing cytohesin, that independently evolved in amoebozoans and members of the SAR and haptophyte clades. Building on evolutionary data for the ARF family GTPases and their GTPase--activating proteins allowed the generation of hypotheses about ARF GEF protein function(s) as well as a better understanding of the origins and evolution of cellular complexity in eukaryotes.
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Affiliation(s)
- Shweta V Pipaliya
- Department of Medicine, Division of Infectious Diseases, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2S2, Canada
| | - Alexander Schlacht
- Department of Medicine, Division of Infectious Diseases, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2S2, Canada
| | - Christen M Klinger
- Department of Medicine, Division of Infectious Diseases, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2S2, Canada
| | - Richard A Kahn
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
| | - Joel Dacks
- Department of Medicine, Division of Infectious Diseases, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2S2, Canada.,Department of Life Sciences, The Natural History Museum, London SW7 5BD, United Kingdom
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Sztul E, Chen PW, Casanova JE, Cherfils J, Dacks JB, Lambright DG, Lee FJS, Randazzo PA, Santy LC, Schürmann A, Wilhelmi I, Yohe ME, Kahn RA. ARF GTPases and their GEFs and GAPs: concepts and challenges. Mol Biol Cell 2019; 30:1249-1271. [PMID: 31084567 PMCID: PMC6724607 DOI: 10.1091/mbc.e18-12-0820] [Citation(s) in RCA: 156] [Impact Index Per Article: 31.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 02/26/2019] [Accepted: 03/11/2019] [Indexed: 12/12/2022] Open
Abstract
Detailed structural, biochemical, cell biological, and genetic studies of any gene/protein are required to develop models of its actions in cells. Studying a protein family in the aggregate yields additional information, as one can include analyses of their coevolution, acquisition or loss of functionalities, structural pliability, and the emergence of shared or variations in molecular mechanisms. An even richer understanding of cell biology can be achieved through evaluating functionally linked protein families. In this review, we summarize current knowledge of three protein families: the ARF GTPases, the guanine nucleotide exchange factors (ARF GEFs) that activate them, and the GTPase-activating proteins (ARF GAPs) that have the ability to both propagate and terminate signaling. However, despite decades of scrutiny, our understanding of how these essential proteins function in cells remains fragmentary. We believe that the inherent complexity of ARF signaling and its regulation by GEFs and GAPs will require the concerted effort of many laboratories working together, ideally within a consortium to optimally pool information and resources. The collaborative study of these three functionally connected families (≥70 mammalian genes) will yield transformative insights into regulation of cell signaling.
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Affiliation(s)
- Elizabeth Sztul
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Pei-Wen Chen
- Department of Biology, Williams College, Williamstown, MA 01267
| | - James E. Casanova
- Department of Cell Biology, University of Virginia, Charlottesville, VA 22908
| | - Jacqueline Cherfils
- Laboratoire de Biologie et Pharmacologie Appliquée, CNRS and Ecole Normale Supérieure Paris-Saclay, 94235 Cachan, France
| | - Joel B. Dacks
- Division of Infectious Disease, Department of Medicine, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - David G. Lambright
- Program in Molecular Medicine and Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Amherst, MA 01605
| | - Fang-Jen S. Lee
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei 10002, Taiwan
| | | | - Lorraine C. Santy
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802
| | - Annette Schürmann
- German Institute of Human Nutrition, 85764 Potsdam-Rehbrücke, Germany
| | - Ilka Wilhelmi
- German Institute of Human Nutrition, 85764 Potsdam-Rehbrücke, Germany
| | - Marielle E. Yohe
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892
| | - Richard A. Kahn
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322-3050
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Hwang SH, Somatilaka BN, Badgandi H, Palicharla VR, Walker R, Shelton JM, Qian F, Mukhopadhyay S. Tulp3 Regulates Renal Cystogenesis by Trafficking of Cystoproteins to Cilia. Curr Biol 2019; 29:790-802.e5. [PMID: 30799239 DOI: 10.1016/j.cub.2019.01.047] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 11/09/2018] [Accepted: 01/17/2019] [Indexed: 12/25/2022]
Abstract
Polycystic kidney disease proteins, polycystin-1 and polycystin-2, localize to primary cilia. Polycystin knockouts have severe cystogenesis compared to ciliary disruption, whereas simultaneous ciliary loss suppresses excessive cyst growth. These data suggest the presence of a cystogenic activator that is inhibited by polycystins and an independent but relatively minor cystogenic inhibitor, either of which are cilia dependent. However, current genetic models targeting cilia completely ablate the compartment, making it difficult to uncouple cystoprotein function from ciliary localization. Thus, the role of cilium-generated signaling in cystogenesis is unclear. We recently demonstrated that the tubby family protein Tulp3 determines ciliary trafficking of polycystins in kidney collecting duct cells without affecting protein levels or cilia. Here, we demonstrate that embryonic-stage, nephron-specific Tulp3 knockout mice developed cystic kidneys, while retaining intact cilia. Cystic kidneys showed increased mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK), mTOR, and persistently high cyclic AMP (cAMP) signaling, suggesting contribution of multiple factors to cystogenesis. Based on kidney-to-body-weight ratio, cystic index, and epithelial proliferation in developing tubules or cysts, the severity of cystogenesis upon Tulp3 deletion was intermediate between that caused by loss of polycystin-1 or cilia. However, concomitant Tulp3 loss did not inhibit cystogenesis in polycystin-1 knockouts, unlike ciliary disruption. Interestingly, ciliary trafficking of the small guanosine triphosphatase (GTPase) Arl13b, loss of which causes cystogenic severity similar to ciliary loss, was reduced prior to cyst initiation. Thus, we propose that cystogenesis in Tulp3 mutants results from a reduction of ciliary levels of polycystins, Arl13b, and Arl13b-dependent lipidated cargoes. Arl13b might be the ciliary factor that represses cystogenesis distinct from polycystins.
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Affiliation(s)
- Sun-Hee Hwang
- Department of Cell Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA
| | - Bandarigoda N Somatilaka
- Department of Cell Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA
| | - Hemant Badgandi
- Department of Cell Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA
| | - Vivek Reddy Palicharla
- Department of Cell Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA
| | - Rebecca Walker
- Division of Nephrology, University of Maryland School of Medicine, 655 West Baltimore Street, Baltimore, MD 21201, USA
| | - John M Shelton
- Department of Internal Medicine, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA
| | - Feng Qian
- Division of Nephrology, University of Maryland School of Medicine, 655 West Baltimore Street, Baltimore, MD 21201, USA
| | - Saikat Mukhopadhyay
- Department of Cell Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.
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Dilan TL, Moye AR, Salido EM, Saravanan T, Kolandaivelu S, Goldberg AFX, Ramamurthy V. ARL13B, a Joubert Syndrome-Associated Protein, Is Critical for Retinogenesis and Elaboration of Mouse Photoreceptor Outer Segments. J Neurosci 2019; 39:1347-1364. [PMID: 30573647 PMCID: PMC6381253 DOI: 10.1523/jneurosci.1761-18.2018] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 11/16/2018] [Accepted: 12/12/2018] [Indexed: 11/21/2022] Open
Abstract
Mutations in the Joubert syndrome-associated small GTPase ARL13B are linked to photoreceptor impairment and vision loss. To determine the role of ARL13B in the development, function, and maintenance of ciliated photoreceptors, we generated a pan-retina knock-out (Six3-Cre) and a rod photoreceptor-specific inducible conditional knock-out (Pde6g-CreERT2) of ARL13B using murine models. Embryonic deletion of ARL13B led to defects in retinal development with reduced cell proliferation. In the absence of ARL13B, photoreceptors failed to develop outer segment (OS) membranous discs and axonemes, resulting in loss of function and rapid degeneration. Additionally, the majority of photoreceptor basal bodies did not dock properly at the apical edge of the inner segments. The removal of ARL13B in adult rod photoreceptor cells after maturation of OS resulted in loss of photoresponse and vesiculation in the OS. Before changes in photoresponse, removal of ARL13B led to mislocalization of rhodopsin, prenylated phosphodiesterase-6 (PDE6), and intraflagellar transport protein-88 (IFT88). Our findings show that ARL13B is required at multiple stages of retinogenesis, including early postnatal proliferation of retinal progenitor cells, development of photoreceptor cilia, and morphogenesis of photoreceptor OS discs regardless of sex. Last, our results establish a need for ARL13B in photoreceptor maintenance and protein trafficking.SIGNIFICANCE STATEMENT The normal development of photoreceptor cilia is essential to create functional, organized outer segments with stacked membrane discs that house the phototransduction proteins necessary for sight. Our study identifies a complex role for ARL13B, a small GTPase linked to Joubert syndrome and visual impairment, at various stages of photoreceptor development. Loss of ARL13B led to defects in retinal proliferation, altered placement of basal bodies crucial for components of the cilium (transition zone) to emanate, and absence of photoreceptor-stacked discs. These defects led to extinguished visual response and dysregulated protein trafficking. Our findings show the complex role ARL13B plays in photoreceptor development, viability, and function. Our study accounts for the severe retinal impairment observed in ARL13B-linked Joubert syndrome patients.
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Affiliation(s)
- Tanya L Dilan
- Department of Ophthalmology and Neuroscience
- Department of Biochemistry
| | - Abigail R Moye
- Department of Ophthalmology and Neuroscience
- Department of Biochemistry
| | | | | | | | | | - Visvanathan Ramamurthy
- Department of Ophthalmology and Neuroscience,
- Department of Biochemistry
- WVU Rockefeller Neuroscience Institute, West Virginia University, Morgantown, West Virginia 26506, and
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36
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Picariello T, Brown JM, Hou Y, Swank G, Cochran DA, King OD, Lechtreck K, Pazour GJ, Witman GB. A global analysis of IFT-A function reveals specialization for transport of membrane-associated proteins into cilia. J Cell Sci 2019; 132:jcs220749. [PMID: 30659111 PMCID: PMC6382014 DOI: 10.1242/jcs.220749] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 01/02/2019] [Indexed: 12/28/2022] Open
Abstract
Intraflagellar transport (IFT), which is essential for the formation and function of cilia in most organisms, is the trafficking of IFT trains (i.e. assemblies of IFT particles) that carry cargo within the cilium. Defects in IFT cause several human diseases. IFT trains contain the complexes IFT-A and IFT-B. To dissect the functions of these complexes, we studied a Chlamydomonas mutant that is null for the IFT-A protein IFT140. The mutation had no effect on IFT-B but destabilized IFT-A, preventing flagella assembly. Therefore, IFT-A assembly requires IFT140. Truncated IFT140, which lacks the N-terminal WD repeats of the protein, partially rescued IFT and supported formation of half-length flagella that contained normal levels of IFT-B but greatly reduced amounts of IFT-A. The axonemes of these flagella had normal ultrastructure and, as investigated by SDS-PAGE, normal composition. However, composition of the flagellar 'membrane+matrix' was abnormal. Analysis of the latter fraction by mass spectrometry revealed decreases in small GTPases, lipid-anchored proteins and cell signaling proteins. Thus, IFT-A is specialized for the import of membrane-associated proteins. Abnormal levels of the latter are likely to account for the multiple phenotypes of patients with defects in IFT140.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Tyler Picariello
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Jason M Brown
- Department of Biology, Salem State University, Salem, MA 01970, USA
| | - Yuqing Hou
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Gregory Swank
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Deborah A Cochran
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Oliver D King
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Karl Lechtreck
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
| | - Gregory J Pazour
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - George B Witman
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA 01655, USA
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37
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Baehr W, Hanke-Gogokhia C, Sharif A, Reed M, Dahl T, Frederick JM, Ying G. Insights into photoreceptor ciliogenesis revealed by animal models. Prog Retin Eye Res 2018; 71:26-56. [PMID: 30590118 DOI: 10.1016/j.preteyeres.2018.12.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 12/10/2018] [Accepted: 12/18/2018] [Indexed: 12/11/2022]
Abstract
Photoreceptors are polarized neurons, with very specific subcellular compartmentalization and unique requirements for protein expression and trafficking. Each photoreceptor contains an outer segment, the site of photon capture that initiates vision, an inner segment that houses the biosynthetic machinery and a synaptic terminal for signal transmission to downstream neurons. Outer segments and inner segments are connected by a connecting cilium (CC), the equivalent of a transition zone (TZ) of primary cilia. The connecting cilium is part of the basal body/axoneme backbone that stabilizes the outer segment. This report will update the reader on late developments in photoreceptor ciliogenesis and transition zone formation, specifically in mouse photoreceptors, focusing on early events in photoreceptor ciliogenesis. The connecting cilium, an elongated and narrow structure through which all outer segment proteins and membrane components must traffic, functions as a gate that controls access to the outer segment. Here we will review genes and their protein products essential for basal body maturation and for CC/TZ genesis, sorted by phenotype. Emphasis is given to naturally occurring mouse mutants and gene knockouts that interfere with CC/TZ formation and ciliogenesis.
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Affiliation(s)
- Wolfgang Baehr
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA.
| | - Christin Hanke-Gogokhia
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
| | - Ali Sharif
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
| | - Michelle Reed
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
| | - Tiffanie Dahl
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
| | - Jeanne M Frederick
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
| | - Guoxin Ying
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
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Zhang Y, Huang Y, Srivathsan A, Lim TK, Lin Q, He CY. The unusual flagellar-targeting mechanism and functions of the trypanosome ortholog of the ciliary GTPase Arl13b. J Cell Sci 2018; 131:jcs.219071. [PMID: 30097558 PMCID: PMC6140319 DOI: 10.1242/jcs.219071] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Accepted: 07/28/2018] [Indexed: 12/11/2022] Open
Abstract
The small GTPase Arl13b is one of the most conserved and ancient ciliary proteins. In human and animals, Arl13b is primarily associated with the ciliary membrane, where it acts as a guanine-nucleotide-exchange factor (GEF) for Arl3 and is implicated in a variety of ciliary and cellular functions. We have identified and characterized Trypanosoma brucei (Tb)Arl13, the sole Arl13b homolog in this evolutionarily divergent, protozoan parasite. TbArl13 has conserved flagellar functions and exhibits catalytic activity towards two different TbArl3 homologs. However, TbArl13 is distinctly associated with the axoneme through a dimerization/docking (D/D) domain. Replacing the D/D domain with a sequence encoding a flagellar membrane protein created a viable alternative to the wild-type TbArl13 in our RNA interference (RNAi)-based rescue assay. Therefore, flagellar enrichment is crucial for TbArl13, but mechanisms to achieve this could be flexible. Our findings thus extend the understanding of the roles of Arl13b and Arl13b–Arl3 pathway in a divergent flagellate of medical importance. This article has an associated First Person interview with the first author of the paper. Highlighted Article: All roads lead to cilia – how the essential flagellar enrichment of Arl13 is achieved in trypanosome cells using a fundamentally different strategy compared with that of animal cells.
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Affiliation(s)
- Yiliu Zhang
- Department of Biological Sciences, Faculty of Science, National University of Singapore, 14 Science Drive 4, Singapore 117543
| | - Yameng Huang
- Department of Biological Sciences, Faculty of Science, National University of Singapore, 14 Science Drive 4, Singapore 117543
| | - Amrita Srivathsan
- Department of Biological Sciences, Faculty of Science, National University of Singapore, 14 Science Drive 4, Singapore 117543
| | - Teck Kwang Lim
- Department of Biological Sciences, Faculty of Science, National University of Singapore, 14 Science Drive 4, Singapore 117543
| | - Qingsong Lin
- Department of Biological Sciences, Faculty of Science, National University of Singapore, 14 Science Drive 4, Singapore 117543
| | - Cynthia Y He
- Department of Biological Sciences, Faculty of Science, National University of Singapore, 14 Science Drive 4, Singapore 117543
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Revenkova E, Liu Q, Gusella GL, Iomini C. The Joubert syndrome protein ARL13B binds tubulin to maintain uniform distribution of proteins along the ciliary membrane. J Cell Sci 2018; 131:jcs212324. [PMID: 29592971 PMCID: PMC5992585 DOI: 10.1242/jcs.212324] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 03/23/2018] [Indexed: 01/09/2023] Open
Abstract
Cilia-mediated signal transduction involves precise targeting and localization of selected molecules along the ciliary membrane. However, the molecular mechanism underlying these events is unclear. The Joubert syndrome protein ARL13B is a membrane-associated G-protein that localizes along the cilium and functions in protein transport and signaling. We identify tubulin as a direct interactor of ARL13B and demonstrate that the association occurs via the G-domain and independently from the GTPase activity of ARL13B. The G-domain is necessary for the interaction of ARL13B with the axoneme both in vitro and in vivo We further show that exogenously expressed mutants lacking the tubulin-binding G-domain (ARL13B-ΔGD) or whose GTPase domain is inactivated (ARL13B-T35N) retain ciliary localization, but fail to rescue ciliogenesis defects of null Arl13bhnn mouse embryonic fibroblasts (MEFs). However, while ARL13B-ΔGD and the membrane proteins Smoothened (SMO) and Somatostatin receptor-3 (SSTR3) distribute unevenly along the cilium of Arl13bhnn MEFs, ARL13B-T35N distributes evenly along the cilium and enables the uniform distribution of SMO and SSTR3. Thus, we propose a so far unknown function of ARL13B in anchoring ciliary membrane proteins to the axoneme through the direct interaction of its G-domain with tubulin.
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Affiliation(s)
- Ekaterina Revenkova
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
| | - Qing Liu
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
| | - G Luca Gusella
- Department of Medicine, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
- Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
| | - Carlo Iomini
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
- Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
- Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
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40
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Kanie T, Jackson PK. Guanine Nucleotide Exchange Assay Using Fluorescent MANT-GDP. Bio Protoc 2018; 8:e2795. [PMID: 29951569 DOI: 10.21769/bioprotoc.2795] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
GTPases are molecular switches that cycle between the inactive GDP-bound state and the active GTP-bound state. GTPases exchange nucleotides either by its intrinsic nucleotide exchange or by interaction with guanine nucleotide exchange factors (GEFs). Monitoring the nucleotide exchange in vitro, together with reconstitution of direct interactions with regulatory proteins, provides key insights into how a GTPase is activated. In this protocol, we describe core methods to monitor nucleotide exchange using fluorescent N-Methylanthraniloyl (MANT)-guanine nucleotide.
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Affiliation(s)
- Tomoharu Kanie
- Baxter Laboratory, Department of Microbiology & Immunology and Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA
| | - Peter K Jackson
- Baxter Laboratory, Department of Microbiology & Immunology and Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA
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41
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Rafiullah R, Long AB, Ivanova AA, Ali H, Berkel S, Mustafa G, Paramasivam N, Schlesner M, Wiemann S, Wade RC, Bolthauser E, Blum M, Kahn RA, Caspary T, Rappold GA. A novel homozygous ARL13B variant in patients with Joubert syndrome impairs its guanine nucleotide-exchange factor activity. Eur J Hum Genet 2017; 25:1324-1334. [PMID: 29255182 PMCID: PMC5865152 DOI: 10.1038/s41431-017-0031-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 10/02/2017] [Accepted: 10/10/2017] [Indexed: 11/09/2022] Open
Abstract
ARL13B encodes for the ADP-ribosylation factor-like 13B GTPase, which is required for normal cilia structure and Sonic hedgehog (Shh) signaling. Disruptions in cilia structure or function lead to a class of human disorders called ciliopathies. Joubert syndrome is characterized by a wide spectrum of symptoms, including a variable degree of intellectual disability, ataxia, and ocular abnormalities. Here we report a novel homozygous missense variant c.[223G>A] (p.(Gly75Arg) in the ARL13B gene, which was identified by whole-exome sequencing of a trio from a consanguineous family with multiple-affected individuals suffering from intellectual disability, ataxia, ocular defects, and epilepsy. The same variant was also identified in a second family. We saw a striking difference in the severity of ataxia between affected male and female individuals in both families. Both ARL13B and ARL13B-c.[223G>A] (p.(Gly75Arg) expression rescued the cilia length and Shh defects displayed by Arl13b hennin (null) cells, indicating that the variant did not disrupt either ARL13B function. In contrast, ARL13B-c.[223G>A] (p.(Gly75Arg) displayed a marked loss of ARL3 guanine nucleotide-exchange factor activity, with retention of its GTPase activities, highlighting the correlation between its loss of function as an ARL3 guanine nucleotide-exchange factor and Joubert syndrome.
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Affiliation(s)
- Rafiullah Rafiullah
- Department of Human Molecular Genetics, Heidelberg University, 69120, Heidelberg, Germany
| | - Alyssa B Long
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Anna A Ivanova
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Hazrat Ali
- Department of Psychiatry, Bolan Medical College, 87600, Quetta, Pakistan
| | - Simone Berkel
- Department of Human Molecular Genetics, Heidelberg University, 69120, Heidelberg, Germany
| | - Ghulam Mustafa
- Molecular and Cellular Modeling (MCM) Group, Heidelberg Institute for Theoretical Studies (HITS), 69118, Heidelberg, Germany
- Center for Molecular Biology, DKFZ-ZMBH Alliance, Heidelberg University, 69120, Heidelberg, Germany
| | - Nagarajan Paramasivam
- Computational Oncology Group, Theoretical Bioinformatics Division (B080), German Cancer Research Centre (DKFZ), 69120, Heidelberg, Germany
- Medical Faculty Heidelberg, Heidelberg University, 69120, Heidelberg, Germany
| | - Matthias Schlesner
- Computational Oncology Group, Theoretical Bioinformatics Division (B080), German Cancer Research Centre (DKFZ), 69120, Heidelberg, Germany
| | - Stefan Wiemann
- Genomic and Proteomics Core Facility, German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany
| | - Rebecca C Wade
- Molecular and Cellular Modeling (MCM) Group, Heidelberg Institute for Theoretical Studies (HITS), 69118, Heidelberg, Germany
- Center for Molecular Biology, DKFZ-ZMBH Alliance, Heidelberg University, 69120, Heidelberg, Germany
| | - Eugen Bolthauser
- Division of Pediatric Neurology, University Children's Hospital, 8032, Zurich, Switzerland
| | - Martin Blum
- Institute of Zoology, University of Hohenheim, 70593, Stuttgart, Germany
| | - Richard A Kahn
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Tamara Caspary
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Gudrun A Rappold
- Department of Human Molecular Genetics, Heidelberg University, 69120, Heidelberg, Germany.
- Interdisciplinary Centre for Neurosciences (IZN), University of Heidelberg, 69120, Heidelberg, Germany.
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