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Feathers JR, Vignogna RC, Fromme JC. Structural basis for Rab6 activation by the Ric1-Rgp1 complex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.06.592747. [PMID: 38766083 PMCID: PMC11100747 DOI: 10.1101/2024.05.06.592747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Rab GTPases act as molecular switches to regulate organelle homeostasis and membrane trafficking. Rab6 plays a central role in regulating cargo flux through the Golgi and is activated via nucleotide exchange by the Ric1-Rgp1 protein complex. Ric1-Rgp1 is conserved throughout eukaryotes but the structural and mechanistic basis for its function has not been established. Here we report the cryoEM structure of a Ric1-Rgp1-Rab6 complex representing a key intermediate of the nucleotide exchange reaction. This structure reveals the overall architecture of the complex and enabled us to identify interactions critical for proper recognition and activation of Rab6 on the Golgi membrane surface. Ric1-Rgp1 interacts with the nucleotide-binding domain of Rab6 using an uncharacterized helical domain, which we establish as a novel RabGEF domain by identifying residues required for Rab6 nucleotide exchange. Unexpectedly, the complex uses an arrestin fold to interact with the Rab6 hypervariable domain, indicating that interactions with the unstructured C-terminal regions of Rab GTPases may be a common specificity mechanism used by their activators. Collectively, our findings provide a detailed mechanistic understanding of regulated Rab6 activation at the Golgi.
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Affiliation(s)
- J. Ryan Feathers
- Department of Molecular Biology & Genetics and Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14850 USA
- Current address: 201 Schultz Laboratory, Princeton University, Princeton, NJ 08544 USA
| | - Ryan C. Vignogna
- Department of Molecular Biology & Genetics and Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14850 USA
| | - J. Christopher Fromme
- Department of Molecular Biology & Genetics and Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14850 USA
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2
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Diao J, Yip CK, Zhong Q. Molecular structures and function of the autophagosome-lysosome fusion machinery. AUTOPHAGY REPORTS 2024; 3:2305594. [PMID: 38344192 PMCID: PMC10852212 DOI: 10.1080/27694127.2024.2305594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 01/09/2024] [Indexed: 02/15/2024]
Abstract
Macroautophagy (also known as autophagy) plays a pivotal role in maintaining cellular homeostasis. The terminal step of the multi-step autophagy degradation pathway involves fusion between the cargo-laden, double-membraned autophagosome and the lytic organelle lysosome/vacuole. Over the past decade, various core components of the molecular machinery that execute this critical terminal autophagy event have been identified. This review highlights recent advances in understanding the molecular structures, biochemical functions, and regulatory mechanisms of key components of this highly sophisticated machinery including the SNARE fusogens, tethering factors, Rab GTPases and associated guanine nucleotide exchange factors, and other accessory factors.
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Affiliation(s)
- Jiajie Diao
- Department of Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, Ohio, U.S.A
| | - Calvin K. Yip
- Life Sciences Institute, Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Qing Zhong
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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3
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Iwagawa T, Masumoto H, Tabuchi H, Tani K, Conklin BR, Watanabe S. Evaluation of CRISPR/Cas9 exon-skipping vector for choroideremia using human induced pluripotent stem cell-derived RPE. J Gene Med 2023; 25:e3464. [PMID: 36413603 PMCID: PMC9898118 DOI: 10.1002/jgm.3464] [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: 02/25/2022] [Revised: 10/21/2022] [Accepted: 11/13/2022] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Exon-skipping is a powerful genetic tool, especially when delivering genes using an AAV-mediated full-length gene supplementation strategy is difficult owing to large length of genes. Here, we used engineered human induced pluripotent stem cells and artificial intelligence to evaluate clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR associated protein 9-based exon-skipping vectors targeting genes of the retinal pigment epithelium (RPE). The model system was choroideremia; this is an X-linked inherited retinal disease caused by mutation of the CHM gene. METHODS We explored whether artificial intelligence detected differentiation of human OTX2, PAX6 and MITF (hOPM) cells, in which OTX2, PAX6 and MITF expression was induced by doxycycline treatment, into RPE. Plasmid encoding CHM exon-skipping modules targeting the splice donor sites of exons 6 were constructed. A clonal hOPM cell line with a frameshift mutation in exon 6 was generated and differentiated into RPE. CHM exon 6-skipping was induced, and the effects of skipping on phagocytic activity, cell death and prenylation of Rab small GTPase (RAB) were evaluated using flow cytometry, an in vitro prenylation assay and western blotting. RESULTS Artificial intelligence-based evaluation of RPE differentiation was successful. Retinal pigment epithelium cells with a frameshift mutation in exon 6 showed increased cell death, reduced phagocytic activity and increased cytosolic unprenylated RABs only when oxidative stress was in play. The latter two phenotypes were partially rescued by exon 6-skipping of CHM. CONCLUSIONS CHM exon 6-skipping contributed to RPE phagocytosis probably by increasing RAB38 prenylation under oxidative stress.
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Affiliation(s)
- Toshiro Iwagawa
- Division of Molecular and Developmental Biology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
- Department of Retinal Biology and Pathology, University of Tokyo Hospital, University of Tokyo, Tokyo, Japan
| | - Hiroki Masumoto
- Xeno Hoc, inc
- Department of Ophthalmology, Tsukazaki Hospital, Hyogo, Japan
| | - Hitoshi Tabuchi
- Department of Ophthalmology, Tsukazaki Hospital, Hyogo, Japan
- Department of Technology and Design Thinking for Medicine, Hiroshima University, Hiroshima, Japan
| | - Kenzaburo Tani
- Laboratory of ALA Advanced Medical Research, Institute for quantitative Biosciences, University of Tokyo, Tokyo, Japan
| | - Bruce R. Conklin
- Gladstone Institutes, San Francisco, CA, USA
- Departments of Medicine, Ophthalmology & Cellular and Molecular Pharmacology University of California, San Francisco, CA, United States, USA
| | - Sumiko Watanabe
- Division of Molecular and Developmental Biology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
- Department of Retinal Biology and Pathology, University of Tokyo Hospital, University of Tokyo, Tokyo, Japan
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Novel RAB27A Variant Associated with Late-Onset Hemophagocytic Lymphohistiocytosis Alters Effector Protein Binding. J Clin Immunol 2022; 42:1685-1695. [DOI: 10.1007/s10875-022-01315-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 06/22/2022] [Indexed: 11/25/2022]
Abstract
Abstract
Autosomal recessive mutations in RAB27A are associated with Griscelli syndrome type 2 (GS2), characterized by hypopigmentation and development of early-onset, potentially fatal hemophagocytic lymphohistiocytosis (HLH). We describe a 35-year old male who presented with recurrent fever, was diagnosed with Epstein-Barr virus-driven chronic lymphoproliferation, fulfilled clinical HLH criteria, and who carried a novel homozygous RAB27A c.551G > A p.(R184Q) variant. We aimed to evaluate the contribution of the identified RAB27A variant in regard to the clinical phenotype as well as cellular and biochemical function. The patient displayed normal pigmentation as well as RAB27A expression in blood-derived cells. However, patient NK and CD8+ T cell exocytosis was low. Ectopic expression of the RAB27A p.R184Q variant rescued melanosome distribution in mouse Rab27a-deficient melanocytes, but failed to increase exocytosis upon reconstitution of human RAB27A-deficient CD8+ T cells. Mechanistically, the RAB27A p.R184Q variant displayed reduced binding to SLP2A but augmented binding to MUNC13-4, two key effector proteins in immune cells. MUNC13-4 binding was particularly strong to an inactive RAB27A p.T23N/p.R184Q double mutant. RAB27A p.R184Q was expressed and could facilitate melanosome trafficking, but did not support lymphocyte exocytosis. The HLH-associated RAB27A variant increased Munc13-4 binding, potentially representing a novel mode of impairing RAB27A function selectively in hematopoietic cells.
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5
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Di Giosaffatte N, Valiante M, Tricarico S, Parise G, De Negri AM, Ricciotti G, Florean L, Paiardini A, Bottillo I, Grammatico P. A Novel Hypothesis on Choroideremia-Manifesting Female Carriers: Could CHM In-Frame Variants Exert a Dominant Negative Effect? A Case Report. Genes (Basel) 2022; 13:1268. [PMID: 35886051 PMCID: PMC9321261 DOI: 10.3390/genes13071268] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 07/08/2022] [Accepted: 07/14/2022] [Indexed: 02/01/2023] Open
Abstract
Choroideremia is an X-linked recessive condition presenting in males, with progressive degeneration of retinal and choroidal tissues leading to progressive visual loss. Its pathological mechanism is due to alterations in the CHM gene that encodes for REP1, a protein required for prenylation of Rab by the Rab geranylgeranyl transferase (RGGT). Even though female carriers are predicted to be not affected by the disease, a wide phenotypic spectrum ranging from mild to severe cases has been reported in women. The reason why Choroideremia manifests in female carriers remains elusive. While X chromosome inactivation (XCI) skewing has been proposed as a leading putative mechanism, emerging evidence has shown that CHM could variably escape from XCI. We described a family with an initial clinical suspicion of Retinitis Pigmentosa in which a novel CHM pathogenic splicing variant was found by exome sequencing. The variant, initially found in the 63-year-old female presenting with impaired visual acuity and severe retinal degeneration, segregated in the 31-year-old daughter and the 37-year-old son, both presenting with fundus anomalies. mRNA studies revealed a shorter in-frame CHM isoform lacking exon 10. Molecular modeling of the ternary REP1/Rab/RGGT protein complex predicted significant impairing of REP1/Rab binding without alteration of REP1/RGGT interaction. We suggest that, in our female cases, the biallelic expression of CHM may have led to the production of both the mutant and wild type REP1. The mutant isoform, sequestrating RGGT, could reduce its available amount for Rab prenylation, thus exerting a dominant-negative effect. If confirmed with further studies and in large cohorts of female carriers, the here proposed molecular mechanism could help to explain the complexity of manifestation of Choroideremia in females.
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Affiliation(s)
- Niccolò Di Giosaffatte
- Division of Medical Genetics, Department of Experimental Medicine, San Camillo-Forlanini Hospital, Sapienza University, 00185 Rome, Italy; (N.D.G.); (M.V.); (G.P.); (L.F.); (P.G.)
| | - Michele Valiante
- Division of Medical Genetics, Department of Experimental Medicine, San Camillo-Forlanini Hospital, Sapienza University, 00185 Rome, Italy; (N.D.G.); (M.V.); (G.P.); (L.F.); (P.G.)
| | | | - Giulia Parise
- Division of Medical Genetics, Department of Experimental Medicine, San Camillo-Forlanini Hospital, Sapienza University, 00185 Rome, Italy; (N.D.G.); (M.V.); (G.P.); (L.F.); (P.G.)
| | - Anna Maria De Negri
- Neuro-Ophthalmology Clinic, San Camillo-Forlanini Hospital, 00152 Rome, Italy;
| | - Guido Ricciotti
- Department of Ophthalmology, University Hospital of Parma, 43126 Parma, Italy;
| | - Lara Florean
- Division of Medical Genetics, Department of Experimental Medicine, San Camillo-Forlanini Hospital, Sapienza University, 00185 Rome, Italy; (N.D.G.); (M.V.); (G.P.); (L.F.); (P.G.)
| | - Alessandro Paiardini
- Department of Biochemical Sciences “A. Rossi Fanelli”, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy;
| | - Irene Bottillo
- Division of Medical Genetics, Department of Molecular Medicine, San Camillo-Forlanini Hospital, Sapienza University, 00185 Rome, Italy
| | - Paola Grammatico
- Division of Medical Genetics, Department of Experimental Medicine, San Camillo-Forlanini Hospital, Sapienza University, 00185 Rome, Italy; (N.D.G.); (M.V.); (G.P.); (L.F.); (P.G.)
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6
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Bagde SR, Fromme JC. Structure of a TRAPPII-Rab11 activation intermediate reveals GTPase substrate selection mechanisms. SCIENCE ADVANCES 2022; 8:eabn7446. [PMID: 35559680 PMCID: PMC9106297 DOI: 10.1126/sciadv.abn7446] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Rab1 and Rab11 are essential regulators of the eukaryotic secretory and endocytic recycling pathways. The transport protein particle (TRAPP) complexes activate these guanosine triphosphatases via nucleotide exchange using a shared set of core subunits. The basal specificity of the TRAPP core is toward Rab1, yet the TRAPPII complex is specific for Rab11. A steric gating mechanism has been proposed to explain TRAPPII counterselection against Rab1. Here, we present cryo-electron microscopy structures of the 22-subunit TRAPPII complex from budding yeast, including a TRAPPII-Rab11 nucleotide exchange intermediate. The Trs130 subunit provides a "leg" that positions the active site distal to the membrane surface, and this leg is required for steric gating. The related TRAPPIII complex is unable to activate Rab11 because of a repulsive interaction, which TRAPPII surmounts using the Trs120 subunit as a "lid" to enclose the active site. TRAPPII also adopts an open conformation enabling Rab11 to access and exit from the active site chamber.
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7
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Marchwicka A, Kamińska D, Monirialamdari M, Błażewska KM, Gendaszewska-Darmach E. Protein Prenyltransferases and Their Inhibitors: Structural and Functional Characterization. Int J Mol Sci 2022; 23:ijms23105424. [PMID: 35628237 PMCID: PMC9141697 DOI: 10.3390/ijms23105424] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 05/07/2022] [Accepted: 05/09/2022] [Indexed: 02/06/2023] Open
Abstract
Protein prenylation is a post-translational modification controlling the localization, activity, and protein–protein interactions of small GTPases, including the Ras superfamily. This covalent attachment of either a farnesyl (15 carbon) or a geranylgeranyl (20 carbon) isoprenoid group is catalyzed by four prenyltransferases, namely farnesyltransferase (FTase), geranylgeranyltransferase type I (GGTase-I), Rab geranylgeranyltransferase (GGTase-II), and recently discovered geranylgeranyltransferase type III (GGTase-III). Blocking small GTPase activity, namely inhibiting prenyltransferases, has been proposed as a potential disease treatment method. Inhibitors of prenyltransferase have resulted in substantial therapeutic benefits in various diseases, such as cancer, neurological disorders, and viral and parasitic infections. In this review, we overview the structure of FTase, GGTase-I, GGTase-II, and GGTase-III and summarize the current status of research on their inhibitors.
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Affiliation(s)
- Aleksandra Marchwicka
- Institute of Molecular and Industrial Biotechnology, Faculty of Biotechnology and Food Sciences, Lodz University of Technology, 90-537 Lodz, Poland; (A.M.); (D.K.)
| | - Daria Kamińska
- Institute of Molecular and Industrial Biotechnology, Faculty of Biotechnology and Food Sciences, Lodz University of Technology, 90-537 Lodz, Poland; (A.M.); (D.K.)
| | - Mohsen Monirialamdari
- Institute of Organic Chemistry, Faculty of Chemistry, Lodz University of Technology, 90-924 Lodz, Poland; (M.M.); (K.M.B.)
| | - Katarzyna M. Błażewska
- Institute of Organic Chemistry, Faculty of Chemistry, Lodz University of Technology, 90-924 Lodz, Poland; (M.M.); (K.M.B.)
| | - Edyta Gendaszewska-Darmach
- Institute of Molecular and Industrial Biotechnology, Faculty of Biotechnology and Food Sciences, Lodz University of Technology, 90-537 Lodz, Poland; (A.M.); (D.K.)
- Correspondence:
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8
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Gutkowska M, Kaus‐Drobek M, Hoffman‐Sommer M, Małgorzata Pamuła M, Daria Leja A, Perycz M, Lichocka M, Witek A, Wojtas M, Dadlez M, Swiezewska E, Surmacz L. Impact of C-terminal truncations in the Arabidopsis Rab escort protein (REP) on REP-Rab interaction and plant fertility. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 108:1400-1421. [PMID: 34592024 PMCID: PMC9293207 DOI: 10.1111/tpj.15519] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 09/27/2021] [Accepted: 09/28/2021] [Indexed: 06/13/2023]
Abstract
Lipid anchors are common post-translational modifications for proteins engaged in signaling and vesicular transport in eukaryotic cells. Rab proteins are geranylgeranylated at their C-termini, a modification which is important for their stable binding to lipid bilayers. The Rab escort protein (REP) is an accessory protein of the Rab geranylgeranyl transferase (RGT) complex and it is obligatory for Rab prenylation. While REP-Rab interactions have been studied by biochemical, structural, and genetic methods in animals and yeast, data on the plant RGT complex are still limited. Here we use hydrogen-deuterium exchange mass spectrometry (HDX-MS) to describe the structural basis of plant REP-Rab binding. The obtained results show that the interaction of REP with Rabs is highly dynamic and involves specific structural changes in both partners. In some cases the Rab and REP regions involved in the interaction are molecule-specific, and in other cases they are common for a subset of Rabs. In particular, the C-terminus of REP is not involved in binding of unprenylated Rab proteins in plants, in contrast to mammalian REP. In line with this, a C-terminal REP truncation does not have pronounced phenotypic effects in planta. On the contrary, a complete lack of functional REP leads to male sterility in Arabidopsis: pollen grains develop in the anthers, but they do not germinate efficiently and hence are unable to transmit the mutated allele. The presented data show that the mechanism of action of REP in the process of Rab geranylgeranylation is different in plants than in animals or yeast.
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Affiliation(s)
- Małgorzata Gutkowska
- Institute of Biochemistry and BiophysicsPolish Academy of Sciencesul. Pawinskiego 5a, 02‐106WarsawPoland
| | - Magdalena Kaus‐Drobek
- Institute of Biochemistry and BiophysicsPolish Academy of Sciencesul. Pawinskiego 5a, 02‐106WarsawPoland
- Mossakowski Medical Research CentrePolish Academy of Sciencesul. Pawinskiego 5, 02‐106WarsawPoland
| | - Marta Hoffman‐Sommer
- Institute of Biochemistry and BiophysicsPolish Academy of Sciencesul. Pawinskiego 5a, 02‐106WarsawPoland
| | | | - Anna Daria Leja
- Institute of Biochemistry and BiophysicsPolish Academy of Sciencesul. Pawinskiego 5a, 02‐106WarsawPoland
| | - Małgorzata Perycz
- Institute of Biochemistry and BiophysicsPolish Academy of Sciencesul. Pawinskiego 5a, 02‐106WarsawPoland
- Institute of Computer SciencePolish Academy of Sciencesul. Jana Kazimierza 501‐248WarsawPoland
| | - Małgorzata Lichocka
- Institute of Biochemistry and BiophysicsPolish Academy of Sciencesul. Pawinskiego 5a, 02‐106WarsawPoland
| | - Agnieszka Witek
- Institute of Biochemistry and BiophysicsPolish Academy of Sciencesul. Pawinskiego 5a, 02‐106WarsawPoland
| | - Magdalena Wojtas
- Institute of Biochemistry and BiophysicsPolish Academy of Sciencesul. Pawinskiego 5a, 02‐106WarsawPoland
| | - Michał Dadlez
- Institute of Biochemistry and BiophysicsPolish Academy of Sciencesul. Pawinskiego 5a, 02‐106WarsawPoland
| | - Ewa Swiezewska
- Institute of Biochemistry and BiophysicsPolish Academy of Sciencesul. Pawinskiego 5a, 02‐106WarsawPoland
| | - Liliana Surmacz
- Institute of Biochemistry and BiophysicsPolish Academy of Sciencesul. Pawinskiego 5a, 02‐106WarsawPoland
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9
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Kalatzis V, Roux AF, Meunier I. Molecular Therapy for Choroideremia: Pre-clinical and Clinical Progress to Date. Mol Diagn Ther 2021; 25:661-675. [PMID: 34661884 DOI: 10.1007/s40291-021-00558-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/09/2021] [Indexed: 12/01/2022]
Abstract
Choroideremia is an inherited retinal disease characterised by a degeneration of the light-sensing photoreceptors, supporting retinal pigment epithelium and underlying choroid. Patients present with the same symptoms as those with classic rod-cone dystrophy: (1) night blindness early in life; (2) progressive peripheral visual field loss, and (3) central vision decline with a slow progression to legal blindness. Choroideremia is monogenic and caused by mutations in CHM. Eight clinical trials (three phase 1/2, four phase 2, and one phase 3) have started (four of which are already finished) to evaluate the therapeutic efficacy of gene supplementation mediated by subretinal delivery of an adeno-associated virus serotype 2 (AAV2/2) vector expressing CHM. Furthermore, one phase 1 clinical trial has been initiated to evaluate the efficiency of a novel AAV variant to deliver CHM to the outer retina following intravitreal delivery. Lastly, a non-viral-mediated CHM replacement strategy is currently under development, which could lead to a future clinical trial. Here, we summarise the rationale behind these various studies, as well as any results published to date. The diversity of these trials currently places choroideremia at the forefront of the retinal gene therapy field. As a consequence, the trial outcomes, regardless of the results, have the potential to change the landscape of gene supplementation for inherited retinal diseases.
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Affiliation(s)
- Vasiliki Kalatzis
- Institute for Neurosciences of Montpellier, Univ Montpellier, Inserm U1298, Hôpital St Eloi, 80 Avenue Augustin Fliche, 34091, Montpellier, France.
| | - Anne-Françoise Roux
- Institute for Neurosciences of Montpellier, Univ Montpellier, Inserm U1298, Hôpital St Eloi, 80 Avenue Augustin Fliche, 34091, Montpellier, France.,Molecular Genetics Laboratory, Univ Montpellier, CHU Montpellier, Montpellier, France
| | - Isabelle Meunier
- Institute for Neurosciences of Montpellier, Univ Montpellier, Inserm U1298, Hôpital St Eloi, 80 Avenue Augustin Fliche, 34091, Montpellier, France.,National Reference Centre for Inherited Sensory Diseases, University of Montpellier, CHU Montpellier, Montpellier, France
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10
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Tang H, Mao J, Xiang J, Liu M, Li H, Wang T. Whole-exome sequencing identified a novel mutation in CHM of a Chinese family. J Genet 2021. [DOI: 10.1007/s12041-021-01282-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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11
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Suazo KF, Park KY, Distefano MD. A Not-So-Ancient Grease History: Click Chemistry and Protein Lipid Modifications. Chem Rev 2021; 121:7178-7248. [PMID: 33821625 DOI: 10.1021/acs.chemrev.0c01108] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Protein lipid modification involves the attachment of hydrophobic groups to proteins via ester, thioester, amide, or thioether linkages. In this review, the specific click chemical reactions that have been employed to study protein lipid modification and their use for specific labeling applications are first described. This is followed by an introduction to the different types of protein lipid modifications that occur in biology. Next, the roles of click chemistry in elucidating specific biological features including the identification of lipid-modified proteins, studies of their regulation, and their role in diseases are presented. A description of the use of protein-lipid modifying enzymes for specific labeling applications including protein immobilization, fluorescent labeling, nanostructure assembly, and the construction of protein-drug conjugates is presented next. Concluding remarks and future directions are presented in the final section.
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Affiliation(s)
- Kiall F Suazo
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Keun-Young Park
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Mark D Distefano
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
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12
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Jenkins ML, Harris NJ, Dalwadi U, Fleming KD, Ziemianowicz DS, Rafiei A, Martin EM, Schriemer DC, Yip CK, Burke JE. The substrate specificity of the human TRAPPII complex's Rab-guanine nucleotide exchange factor activity. Commun Biol 2020; 3:735. [PMID: 33277614 PMCID: PMC7719173 DOI: 10.1038/s42003-020-01459-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 10/13/2020] [Indexed: 12/15/2022] Open
Abstract
The TRAnsport Protein Particle (TRAPP) complexes act as Guanine nucleotide exchange factors (GEFs) for Rab GTPases, which are master regulators of membrane trafficking in eukaryotic cells. In metazoans, there are two large multi-protein TRAPP complexes: TRAPPII and TRAPPIII, with the TRAPPII complex able to activate both Rab1 and Rab11. Here we present detailed biochemical characterisation of Rab-GEF specificity of the human TRAPPII complex, and molecular insight into Rab binding. GEF assays of the TRAPPII complex against a panel of 20 different Rab GTPases revealed GEF activity on Rab43 and Rab19. Electron microscopy and chemical cross-linking revealed the architecture of mammalian TRAPPII. Hydrogen deuterium exchange MS showed that Rab1, Rab11 and Rab43 share a conserved binding interface. Clinical mutations in Rab11, and phosphomimics of Rab43, showed decreased TRAPPII GEF mediated exchange. Finally, we designed a Rab11 mutation that maintained TRAPPII-mediated GEF activity while decreasing activity of the Rab11-GEF SH3BP5, providing a tool to dissect Rab11 signalling. Overall, our results provide insight into the GTPase specificity of TRAPPII, and how clinical mutations disrupt this regulation. Here the authors reveal unique structural organization of the mammalian TRAPPII complex, which is critical in regulating membrane trafficking. They find that TRAPPII serves as a guanine nucleotide exchange factor for unexpected Rab GTPases such as Rab43 and Rab19.
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Affiliation(s)
- Meredith L Jenkins
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, V8W 2Y2, Canada
| | - Noah J Harris
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, V8W 2Y2, Canada
| | - Udit Dalwadi
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
| | - Kaelin D Fleming
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, V8W 2Y2, Canada
| | - Daniel S Ziemianowicz
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Atefeh Rafiei
- Department of Chemistry, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Emily M Martin
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, V8W 2Y2, Canada
| | - David C Schriemer
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, AB, T2N 4N1, Canada.,Department of Chemistry, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Calvin K Yip
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
| | - John E Burke
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, V8W 2Y2, Canada. .,Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada.
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13
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Saito-Nakano Y, Wahyuni R, Nakada-Tsukui K, Tomii K, Nozaki T. Rab7D small GTPase is involved in phago-, trogocytosis and cytoskeletal reorganization in the enteric protozoan Entamoeba histolytica. Cell Microbiol 2020; 23:e13267. [PMID: 32975360 PMCID: PMC7757265 DOI: 10.1111/cmi.13267] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 08/21/2020] [Accepted: 09/18/2020] [Indexed: 12/12/2022]
Abstract
Rab small GTPases regulate membrane traffic between distinct cellular compartments of all eukaryotes in a tempo‐spatially specific fashion. Rab small GTPases are also involved in the regulation of cytoskeleton and signalling. Membrane traffic and cytoskeletal regulation play pivotal role in the pathogenesis of Entamoeba histolytica, which is a protozoan parasite responsible for human amebiasis. E. histolytica is unique in that its genome encodes over 100 Rab proteins, containing multiple isotypes of conserved members (e.g., Rab7) and Entamoeba‐specific subgroups (e.g., RabA, B, and X). Among them, E. histolytica Rab7 is the most diversified group consisting of nine isotypes. While it was previously demonstrated that EhRab7A and EhRab7B are involved in lysosome and phagosome biogenesis, the individual roles of other Rab7 members and their coordination remain elusive. In this study, we characterised the third member of Rab7, Rab7D, to better understand the significance of the multiplicity of Rab7 isotypes in E. histolytica. Overexpression of EhRab7D caused reduction in phagocytosis of erythrocytes, trogocytosis (meaning nibbling or chewing of a portion) of live mammalian cells, and phagosome acidification and maturation. Conversely, transcriptional gene silencing of EhRab7D gene caused opposite phenotypes in phago/trogocytosis and phagosome maturation. Furthermore, EhRab7D gene silencing caused reduction in the attachment to and the motility on the collagen‐coated surface. Image analysis showed that EhRab7D was occasionally associated with lysosomes and prephagosomal vacuoles, but not with mature phagosomes and trogosomes. Finally, in silico prediction of structural organisation of EhRab7 isotypes identified unique amino acid changes on the effector binding surface of EhRab7D. Taken together, our data suggest that EhRab7D plays coordinated counteracting roles: a inhibitory role in phago/trogocytosis and lyso/phago/trogosome biogenesis, and an stimulatory role in adherence and motility, presumably via interaction with unique effectors. Finally, we propose the model in which three EhRab7 isotypes are sequentially involved in phago/trogocytosis.
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Affiliation(s)
- Yumiko Saito-Nakano
- Department of Parasitology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Ratna Wahyuni
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.,Institute of Tropical Disease, Universitas Airlangga, Surabaya, Indonesia.,Department of Health, Faculty of Vocational Studies, Universitas Airlangga, Surabaya, Indonesia
| | - Kumiko Nakada-Tsukui
- Department of Parasitology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Kentaro Tomii
- Artificial Intelligence Research Center (AIRC) and Real World Big-Data Computation Open Innovation Laboratory (RWBC-OIL), National Institute of Advance Industrial Science and Technology (AIST), Tokyo, Japan
| | - Tomoyoshi Nozaki
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
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14
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Abstract
Autophagy (cellular self-eating) is essential for the health and survival of eukaryotic cells. Therapeutic autophagy induction is a major goal in the field. Rubicon inhibits autophagy and is a potential target for autophagy inducers. Rubicon is localized to its site of action in the cell by binding to the small GTPase Rab7. Here, we report a high-resolution structure of a large part of Rubicon, known as the Rubicon Homology (RH) domain. We show how the RH domain binds to Rab7 and show that the Rab7-binding residues of Rubicon are essential for Rubicon localization and autophagy inhibition. This provides a roadmap to block Rubicon localization and activity in order to upregulate autophagy. Rubicon is a potent negative regulator of autophagy and a potential target for autophagy-inducing therapeutics. Rubicon-mediated inhibition of autophagy requires the interaction of the C-terminal Rubicon homology (RH) domain of Rubicon with Rab7–GTP. Here we report the 2.8-Å crystal structure of the Rubicon RH domain in complex with Rab7–GTP. Our structure reveals a fold for the RH domain built around four zinc clusters. The switch regions of Rab7 insert into pockets on the surface of the RH domain in a mode that is distinct from those of other Rab–effector complexes. Rubicon residues at the dimer interface are required for Rubicon and Rab7 to colocalize in living cells. Mutation of Rubicon RH residues in the Rab7-binding site restores efficient autophagic flux in the presence of overexpressed Rubicon, validating the Rubicon RH domain as a promising therapeutic target.
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15
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Cezanne A, Lauer J, Solomatina A, Sbalzarini IF, Zerial M. A non-linear system patterns Rab5 GTPase on the membrane. eLife 2020; 9:54434. [PMID: 32510320 PMCID: PMC7279886 DOI: 10.7554/elife.54434] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 05/21/2020] [Indexed: 12/21/2022] Open
Abstract
Proteins can self-organize into spatial patterns via non-linear dynamic interactions on cellular membranes. Modelling and simulations have shown that small GTPases can generate patterns by coupling guanine nucleotide exchange factors (GEF) to effectors, generating a positive feedback of GTPase activation and membrane recruitment. Here, we reconstituted the patterning of the small GTPase Rab5 and its GEF/effector complex Rabex5/Rabaptin5 on supported lipid bilayers. We demonstrate a 'handover' of Rab5 from Rabex5 to Rabaptin5 upon nucleotide exchange. A minimal system consisting of Rab5, RabGDI and a complex of full length Rabex5/Rabaptin5 was necessary to pattern Rab5 into membrane domains. Rab5 patterning required a lipid membrane composition mimicking that of early endosomes, with PI(3)P enhancing membrane recruitment of Rab5 and acyl chain packing being critical for domain formation. The prevalence of GEF/effector coupling in nature suggests a possible universal system for small GTPase patterning involving both protein and lipid interactions.
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Affiliation(s)
- Alice Cezanne
- Max-Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Janelle Lauer
- Max-Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Anastasia Solomatina
- Max-Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.,Chair of Scientific Computing for Systems Biology, Faculty of Computer Science, Dresden, Germany.,MOSAIC Group, Center for Systems Biology Dresden, Dresden, Germany
| | - Ivo F Sbalzarini
- Max-Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.,Chair of Scientific Computing for Systems Biology, Faculty of Computer Science, Dresden, Germany.,MOSAIC Group, Center for Systems Biology Dresden, Dresden, Germany
| | - Marino Zerial
- Max-Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
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16
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Shirakawa R, Goto‐Ito S, Goto K, Wakayama S, Kubo H, Sakata N, Trinh DA, Yamagata A, Sato Y, Masumoto H, Cheng J, Fujimoto T, Fukai S, Horiuchi H. A SNARE geranylgeranyltransferase essential for the organization of the Golgi apparatus. EMBO J 2020; 39:e104120. [PMID: 32128853 PMCID: PMC7156963 DOI: 10.15252/embj.2019104120] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 01/22/2020] [Accepted: 01/31/2020] [Indexed: 01/08/2023] Open
Abstract
Protein prenylation is essential for many cellular processes including signal transduction, cytoskeletal reorganization, and membrane trafficking. Here, we identify a novel type of protein prenyltransferase, which we named geranylgeranyltransferase type-III (GGTase-III). GGTase-III consists of prenyltransferase alpha subunit repeat containing 1 (PTAR1) and the β subunit of RabGGTase. Using a biotinylated geranylgeranyl analogue, we identified the Golgi SNARE protein Ykt6 as a substrate of GGTase-III. GGTase-III transfers a geranylgeranyl group to mono-farnesylated Ykt6, generating doubly prenylated Ykt6. The crystal structure of GGTase-III in complex with Ykt6 provides structural basis for Ykt6 double prenylation. In GGTase-III-deficient cells, Ykt6 remained in a singly prenylated form, and the Golgi SNARE complex assembly was severely impaired. Consequently, the Golgi apparatus was structurally disorganized, and intra-Golgi protein trafficking was delayed. Our findings reveal a fourth type of protein prenyltransferase that generates geranylgeranyl-farnesyl Ykt6. Double prenylation of Ykt6 is essential for the structural and functional organization of the Golgi apparatus.
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Affiliation(s)
- Ryutaro Shirakawa
- Department of Molecular and Cellular BiologyInstitute of Development, Aging and CancerTohoku UniversitySendaiJapan
| | - Sakurako Goto‐Ito
- Institute for Quantitative BiosciencesThe University of TokyoTokyoJapan
- Synchrotron Radiation Research OrganizationThe University of TokyoTokyoJapan
| | - Kota Goto
- Department of Molecular and Cellular BiologyInstitute of Development, Aging and CancerTohoku UniversitySendaiJapan
| | - Shonosuke Wakayama
- Department of Molecular and Cellular BiologyInstitute of Development, Aging and CancerTohoku UniversitySendaiJapan
| | - Haremaru Kubo
- Department of Molecular and Cellular BiologyInstitute of Development, Aging and CancerTohoku UniversitySendaiJapan
| | - Natsumi Sakata
- Department of Molecular and Cellular BiologyInstitute of Development, Aging and CancerTohoku UniversitySendaiJapan
| | - Duc Anh Trinh
- Department of Molecular and Cellular BiologyInstitute of Development, Aging and CancerTohoku UniversitySendaiJapan
| | - Atsushi Yamagata
- Institute for Quantitative BiosciencesThe University of TokyoTokyoJapan
- Synchrotron Radiation Research OrganizationThe University of TokyoTokyoJapan
| | - Yusuke Sato
- Institute for Quantitative BiosciencesThe University of TokyoTokyoJapan
- Synchrotron Radiation Research OrganizationThe University of TokyoTokyoJapan
- Present address:
Center for Research on Green Sustainable ChemistryTottori UniversityTottoriJapan
| | - Hiroshi Masumoto
- Biomedical Research Support CenterNagasaki University School of MedicineNagasakiJapan
| | - Jinglei Cheng
- Department of Anatomy and Molecular Cell BiologyNagoya University Graduate School of MedicineNagoyaJapan
| | - Toyoshi Fujimoto
- Research Institute for Diseases of Old AgeJuntendo University Graduate School of MedicineTokyoJapan
| | - Shuya Fukai
- Institute for Quantitative BiosciencesThe University of TokyoTokyoJapan
- Synchrotron Radiation Research OrganizationThe University of TokyoTokyoJapan
| | - Hisanori Horiuchi
- Department of Molecular and Cellular BiologyInstitute of Development, Aging and CancerTohoku UniversitySendaiJapan
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17
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Zhang Y, Thery F, Wu NC, Luhmann EK, Dussurget O, Foecke M, Bredow C, Jiménez-Fernández D, Leandro K, Beling A, Knobeloch KP, Impens F, Cossart P, Radoshevich L. The in vivo ISGylome links ISG15 to metabolic pathways and autophagy upon Listeria monocytogenes infection. Nat Commun 2019; 10:5383. [PMID: 31772204 PMCID: PMC6879477 DOI: 10.1038/s41467-019-13393-x] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 11/07/2019] [Indexed: 12/28/2022] Open
Abstract
ISG15 is an interferon-stimulated, ubiquitin-like protein, with anti-viral and anti-bacterial activity. Here, we map the endogenous in vivo ISGylome in the liver following Listeria monocytogenes infection by combining murine models of reduced or enhanced ISGylation with quantitative proteomics. Our method identifies 930 ISG15 sites in 434 proteins and also detects changes in the host ubiquitylome. The ISGylated targets are enriched in proteins which alter cellular metabolic processes, including upstream modulators of the catabolic and antibacterial pathway of autophagy. Computational analysis of substrate structures reveals that a number of ISG15 modifications occur at catalytic sites or dimerization interfaces of enzymes. Finally, we demonstrate that animals and cells with enhanced ISGylation have increased basal and infection-induced autophagy through the modification of mTOR, WIPI2, AMBRA1, and RAB7. Taken together, these findings ascribe a role of ISGylation to temporally reprogram organismal metabolism following infection through direct modification of a subset of enzymes in the liver.
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Affiliation(s)
- Yifeng Zhang
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA
| | - Fabien Thery
- Center for Medical Biotechnology, VIB, 9000, Gent, Belgium
- Department for Biomolecular Medicine, Gent University, 9000, Gent, Belgium
| | - Nicholas C Wu
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Emma K Luhmann
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA
| | - Olivier Dussurget
- Institut Pasteur, Unité des Interactions Bactéries-Cellules, Département de Biologie Cellulaire et Infection, 75015, Paris, France
- Inserm, U604, 75015, Paris, France
- National Institute for Agronomic Research (INRA), Unité sous-contrat 2020, 75015, Paris, France
| | - Mariko Foecke
- Institut Pasteur, Unité des Interactions Bactéries-Cellules, Département de Biologie Cellulaire et Infection, 75015, Paris, France
- Inserm, U604, 75015, Paris, France
- National Institute for Agronomic Research (INRA), Unité sous-contrat 2020, 75015, Paris, France
| | - Clara Bredow
- Charité-Universitäts medizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health (BIH), Institute of Biochemistry, Berlin, Germany
| | | | - Kevin Leandro
- Center for Medical Biotechnology, VIB, 9000, Gent, Belgium
- Department for Biomolecular Medicine, Gent University, 9000, Gent, Belgium
| | - Antje Beling
- Charité-Universitäts medizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health (BIH), Institute of Biochemistry, Berlin, Germany
- Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK), Partner Site Berlin, Berlin, Germany
| | - Klaus-Peter Knobeloch
- Institute of Neuropathology, Medical Faculty, University of Freiburg, Freiburg, Germany
| | - Francis Impens
- Center for Medical Biotechnology, VIB, 9000, Gent, Belgium.
- Department for Biomolecular Medicine, Gent University, 9000, Gent, Belgium.
- VIB Proteomics Core, VIB, 9000, Gent, Belgium.
| | - Pascale Cossart
- Institut Pasteur, Unité des Interactions Bactéries-Cellules, Département de Biologie Cellulaire et Infection, 75015, Paris, France.
- Inserm, U604, 75015, Paris, France.
- National Institute for Agronomic Research (INRA), Unité sous-contrat 2020, 75015, Paris, France.
| | - Lilliana Radoshevich
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA.
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18
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Cehajic Kapetanovic J, Barnard AR, MacLaren RE. Molecular Therapies for Choroideremia. Genes (Basel) 2019; 10:genes10100738. [PMID: 31548516 PMCID: PMC6826983 DOI: 10.3390/genes10100738] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 09/14/2019] [Accepted: 09/20/2019] [Indexed: 01/03/2023] Open
Abstract
Advances in molecular research have culminated in the development of novel gene-based therapies for inherited retinal diseases. We have recently witnessed several groundbreaking clinical studies that ultimately led to approval of Luxturna, the first gene therapy for an inherited retinal disease. In parallel, international research community has been engaged in conducting gene therapy trials for another more common inherited retinal disease known as choroideremia and with phase III clinical trials now underway, approval of this therapy is poised to follow suit. This chapter discusses new insights into clinical phenotyping and molecular genetic testing in choroideremia with review of molecular mechanisms implicated in its pathogenesis. We provide an update on current gene therapy trials and discuss potential inclusion of female carries in future clinical studies. Alternative molecular therapies are discussed including suitability of CRISPR gene editing, small molecule nonsense suppression therapy and vision restoration strategies in late stage choroideremia.
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Affiliation(s)
- Jasmina Cehajic Kapetanovic
- Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford OX3 9DU, UK; (A.R.B.); (R.E.M.)
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
- Correspondence:
| | - Alun R. Barnard
- Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford OX3 9DU, UK; (A.R.B.); (R.E.M.)
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
| | - Robert E. MacLaren
- Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford OX3 9DU, UK; (A.R.B.); (R.E.M.)
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
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19
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CHML promotes liver cancer metastasis by facilitating Rab14 recycle. Nat Commun 2019; 10:2510. [PMID: 31175290 PMCID: PMC6555802 DOI: 10.1038/s41467-019-10364-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Accepted: 04/30/2019] [Indexed: 01/08/2023] Open
Abstract
Metastasis-associated recurrence is the major cause of poor prognosis in hepatocellular carcinoma (HCC), however, the underlying mechanisms remain largely elusive. In this study, we report that expression of choroideremia-like (CHML) is increased in HCC, associated with poor survival, early recurrence and more satellite nodules in HCC patients. CHML promotes migration, invasion and metastasis of HCC cells, in a Rab14-dependent manner. Mechanism study reveals that CHML facilitates constant recycling of Rab14 by escorting Rab14 to the membrane. Furthermore, we identify several metastasis regulators as cargoes carried by Rab14-positive vesicles, including Mucin13 and CD44, which may contribute to metastasis-promoting effects of CHML. Altogether, our data establish CHML as a potential promoter of HCC metastasis, and the CHML-Rab14 axis may be a promising therapeutic target for HCC.
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20
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Edler E, Stein M. Recognition and stabilization of geranylgeranylated human Rab5 by the GDP Dissociation Inhibitor (GDI). Small GTPases 2019; 10:227-242. [PMID: 29065764 PMCID: PMC6548291 DOI: 10.1080/21541248.2017.1371268] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 08/18/2017] [Accepted: 08/18/2017] [Indexed: 01/13/2023] Open
Abstract
The small GTPase Rab5 is the key regulator of early endosomal fusion. It is post-translationally modified by covalent attachment of two geranylgeranyl (GG) chains to adjacent cysteine residues of the C-terminal hypervariable region (HVR). The GDP dissociation inhibitor (GDI) recognizes membrane-associated Rab5(GDP) and serves to release it into the cytoplasm where it is kept in a soluble state. A detailed new structural and dynamic model for human Rab5(GDP) recognition and binding with human GDI at the early endosome membrane and in its dissociated state is presented. In the cytoplasm, the GDI protein accommodates the GG chains in a transient hydrophobic binding pocket. In solution, two different binding modes of the isoprenoid chains inserted into the hydrophobic pocket of the Rab5(GDP):GDI complex can be identified. This equilibrium between the two states helps to stabilize the protein-protein complex in solution. Interprotein contacts between the Rab5 switch regions and characteristic patches of GDI residues from the Rab binding platform (RBP) and the C-terminus coordinating region (CCR) reveal insight on the formation of such a stable complex. GDI binding to membrane-anchored Rab5(GDP) is initially mediated by the solvent accessible switch regions of the Rab-specific RBP. Formation of the membrane-associated Rab5(GDP):GDI complex induces a GDI reorientation to establish additional interactions with the Rab5 HVR. These results allow to devise a detailed structural model for the process of extraction of GG-Rab5(GDP) by GDI from the membrane and the dissociation from targeting factors and effector proteins prior to GDI binding.
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Affiliation(s)
- Eileen Edler
- Molecular Simulations and Design Group, Max Planck Institute for Dynamics of Complex Technical Systems, Magdeburg, Germany
| | - Matthias Stein
- Molecular Simulations and Design Group, Max Planck Institute for Dynamics of Complex Technical Systems, Magdeburg, Germany
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21
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Abstract
The Golgi apparatus is a central sorting station in the cell. It receives newly synthesized molecules from the endoplasmic reticulum and directs them to different subcellular destinations, such as the plasma membrane or the endocytic pathway. Importantly, in the last few years, it has emerged that the maintenance of Golgi structure is connected to the proper regulation of membrane trafficking. Rab proteins are small GTPases that are considered to be the master regulators of the intracellular membrane trafficking. Several of the over 60 human Rabs are involved in the regulation of transport pathways at the Golgi as well as in the maintenance of its architecture. This chapter will summarize the different roles of Rab GTPases at the Golgi, both as regulators of membrane transport, scaffold, and tethering proteins and in preserving the structure and function of this organelle.
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22
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Thomas LL, van der Vegt SA, Fromme JC. A Steric Gating Mechanism Dictates the Substrate Specificity of a Rab-GEF. Dev Cell 2018; 48:100-114.e9. [PMID: 30528786 DOI: 10.1016/j.devcel.2018.11.013] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 10/23/2018] [Accepted: 11/07/2018] [Indexed: 10/27/2022]
Abstract
Correct localization of Rab GTPases in cells is critical for proper function in membrane trafficking, yet the mechanisms that target Rabs to specific subcellular compartments remain controversial. Guanine nucleotide exchange factors (GEFs) activate and consequently stabilize Rab substrates on membranes, thus implicating GEFs as the primary determinants of Rab localization. A competing hypothesis is that the Rab C-terminal hypervariable domain (HVD) serves as a subcellular targeting signal. In this study, we present a unifying mechanism in which the HVD controls targeting of certain Rabs by mediating interaction with their GEFs. We demonstrate that the TRAPP complexes, two related GEFs that use the same catalytic site to activate distinct Rabs, distinguish between Ypt1 (Rab1) and Ypt31/32 (Rab11) via their divergent HVDs. Remarkably, we find that HVD length gates Rab access to the TRAPPII complex by constraining the distance between the nucleotide-binding domain and the membrane surface.
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Affiliation(s)
- Laura L Thomas
- Department of Molecular Biology and Genetics/Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
| | - Solveig A van der Vegt
- Department of Molecular Biology and Genetics/Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
| | - J Christopher Fromme
- Department of Molecular Biology and Genetics/Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA.
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23
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Stroupe C. This Is the End: Regulation of Rab7 Nucleotide Binding in Endolysosomal Trafficking and Autophagy. Front Cell Dev Biol 2018; 6:129. [PMID: 30333976 PMCID: PMC6176412 DOI: 10.3389/fcell.2018.00129] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 09/14/2018] [Indexed: 01/07/2023] Open
Abstract
Rab7 – or in yeast, Ypt7p – governs membrane trafficking in the late endocytic and autophagic pathways. Rab7 also regulates mitochondrion-lysosome contacts, the sites of mitochondrial fission. Like all Rab GTPases, Rab7 cycles between an “active” GTP-bound form that binds downstream effectors – e.g., the HOPS and retromer complexes and the dynactin-binding Rab-interacting lysosomal protein (RILP) – and an “inactive” GDP-bound form that cannot bind effectors. Accessory proteins regulate the nucleotide binding state of Rab7: guanine nucleotide exchange factors (GEFs) stimulate exchange of bound GDP for GTP, resulting in Rab7 activation, whereas GTPase activating proteins (GAPs) boost Rab7’s GTP hydrolysis activity, thereby inactivating Rab7. This review will discuss the GEF and GAPs that control Rab7 nucleotide binding, and thus regulate Rab7’s activity in endolysosomal trafficking and autophagy. It will also consider how bacterial pathogens manipulate Rab7 nucleotide binding to support intracellular invasion and immune evasion.
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Affiliation(s)
- Christopher Stroupe
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, VA, United States
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24
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Ramrath DJF, Niemann M, Leibundgut M, Bieri P, Prange C, Horn EK, Leitner A, Boehringer D, Schneider A, Ban N. Evolutionary shift toward protein-based architecture in trypanosomal mitochondrial ribosomes. Science 2018; 362:science.aau7735. [PMID: 30213880 DOI: 10.1126/science.aau7735] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 09/03/2018] [Indexed: 01/19/2023]
Abstract
Ribosomal RNA (rRNA) plays key functional and architectural roles in ribosomes. Using electron microscopy, we determined the atomic structure of a highly divergent ribosome found in mitochondria of Trypanosoma brucei, a unicellular parasite that causes sleeping sickness in humans. The trypanosomal mitoribosome features the smallest rRNAs and contains more proteins than all known ribosomes. The structure shows how the proteins have taken over the role of architectural scaffold from the rRNA: They form an autonomous outer shell that surrounds the entire particle and stabilizes and positions the functionally important regions of the rRNA. Our results also reveal the "minimal" set of conserved rRNA and protein components shared by all ribosomes that help us define the most essential functional elements.
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Affiliation(s)
- David J F Ramrath
- Department of Biology, Institute of Molecular Biology and Biophysics, Otto-Stern-Weg 5, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Moritz Niemann
- Department of Chemistry and Biochemistry, University of Bern, CH-3012 Bern, Switzerland
| | - Marc Leibundgut
- Department of Biology, Institute of Molecular Biology and Biophysics, Otto-Stern-Weg 5, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Philipp Bieri
- Department of Biology, Institute of Molecular Biology and Biophysics, Otto-Stern-Weg 5, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Céline Prange
- Department of Biology, Institute of Molecular Biology and Biophysics, Otto-Stern-Weg 5, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Elke K Horn
- Department of Chemistry and Biochemistry, University of Bern, CH-3012 Bern, Switzerland
| | - Alexander Leitner
- Department of Biology, Institute of Molecular Systems Biology, Auguste-Piccard-Hof 1, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Daniel Boehringer
- Department of Biology, Institute of Molecular Biology and Biophysics, Otto-Stern-Weg 5, ETH Zurich, CH-8093 Zurich, Switzerland
| | - André Schneider
- Department of Chemistry and Biochemistry, University of Bern, CH-3012 Bern, Switzerland
| | - Nenad Ban
- Department of Biology, Institute of Molecular Biology and Biophysics, Otto-Stern-Weg 5, ETH Zurich, CH-8093 Zurich, Switzerland.
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25
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Patrício MI, Barnard AR, Xue K, MacLaren RE. Choroideremia: molecular mechanisms and development of AAV gene therapy. Expert Opin Biol Ther 2018; 18:807-820. [DOI: 10.1080/14712598.2018.1484448] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Maria I Patrício
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- National Institute for Health Research (NIHR) Oxford Biomedical Research Centre (BRC), Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Alun R Barnard
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- National Institute for Health Research (NIHR) Oxford Biomedical Research Centre (BRC), Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Kanmin Xue
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- National Institute for Health Research (NIHR) Oxford Biomedical Research Centre (BRC), Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Robert E MacLaren
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- National Institute for Health Research (NIHR) Oxford Biomedical Research Centre (BRC), Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
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26
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Abstract
Fruit ripening is a complex developmental process that involves the synthesis and modification of the cell wall leading up to the formation of an edible fruit. During the period of fruit ripening, new cell wall polymers and enzymes are synthesized and trafficked to the apoplast. Vesicle trafficking has been shown to play a key role in facilitating the synthesis and modification of cell walls in fruits. Through reverse genetics and gene expression studies, the importance of Rab guanosine triphosphatases (GTPases) as integral regulators of vesicle trafficking to the cell wall has been revealed. It has been a decade since a rich literature on the involvement of Rab GTPase in ripening was published. Therefore, this review sets out to summarize the progress in studies on the pivotal roles of Rab GTPases in fruit development and sheds light on new approaches that could be adopted in the fields of postharvest biology and fruit-ripening research.
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Affiliation(s)
- Tamunonengiyeofori Lawson
- a School of Biosciences, Faculty of Science , The University of Nottingham, Malaysia Campus , Semenyih , Selangor , Malaysia.,b Division of Plant and Crop Sciences, School of Biosciences , University of Nottingham , Sutton Bonington Campus, Loughborough , Leicestershire , UK.,c Crops for the Future (CFF) , Semenyih , Malaysia
| | - Sean Mayes
- b Division of Plant and Crop Sciences, School of Biosciences , University of Nottingham , Sutton Bonington Campus, Loughborough , Leicestershire , UK.,c Crops for the Future (CFF) , Semenyih , Malaysia
| | - Grantley W Lycett
- b Division of Plant and Crop Sciences, School of Biosciences , University of Nottingham , Sutton Bonington Campus, Loughborough , Leicestershire , UK
| | - Chiew Foan Chin
- a School of Biosciences, Faculty of Science , The University of Nottingham, Malaysia Campus , Semenyih , Selangor , Malaysia
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27
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Pylypenko O, Hammich H, Yu IM, Houdusse A. Rab GTPases and their interacting protein partners: Structural insights into Rab functional diversity. Small GTPases 2018. [PMID: 28632484 DOI: 10.1080/215412481336191] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/23/2023] Open
Abstract
Rab molecular switches are key players in defining membrane identity and regulating intracellular trafficking events in eukaryotic cells. In spite of their global structural similarity, Rab-family members acquired particular features that allow them to perform specific cellular functions. The overall fold and local sequence conservations enable them to utilize a common machinery for prenylation and recycling; while individual Rab structural differences determine interactions with specific partners such as GEFs, GAPs and effector proteins. These interactions orchestrate the spatiotemporal regulation of Rab localization and their turning ON and OFF, leading to tightly controlled Rab-specific functionalities such as membrane composition modifications, recruitment of molecular motors for intracellular trafficking, or recruitment of scaffold proteins that mediate interactions with downstream partners, as well as actin cytoskeleton regulation. In this review we summarize structural information on Rab GTPases and their complexes with protein partners in the context of partner binding specificity and functional outcomes of their interactions in the cell.
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Affiliation(s)
- Olena Pylypenko
- a Structural Motility, Institut Curie , PSL Research University, CNRS, UMR 144 , Paris , France
| | - Hussein Hammich
- a Structural Motility, Institut Curie , PSL Research University, CNRS, UMR 144 , Paris , France
- b Sorbonne Universités , UPMC Univ Paris 06, Sorbonne Universités, IFD , Paris , France
| | - I-Mei Yu
- a Structural Motility, Institut Curie , PSL Research University, CNRS, UMR 144 , Paris , France
| | - Anne Houdusse
- a Structural Motility, Institut Curie , PSL Research University, CNRS, UMR 144 , Paris , France
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28
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Jiang H, Zhang X, Chen X, Aramsangtienchai P, Tong Z, Lin H. Protein Lipidation: Occurrence, Mechanisms, Biological Functions, and Enabling Technologies. Chem Rev 2018; 118:919-988. [PMID: 29292991 DOI: 10.1021/acs.chemrev.6b00750] [Citation(s) in RCA: 283] [Impact Index Per Article: 47.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Protein lipidation, including cysteine prenylation, N-terminal glycine myristoylation, cysteine palmitoylation, and serine and lysine fatty acylation, occurs in many proteins in eukaryotic cells and regulates numerous biological pathways, such as membrane trafficking, protein secretion, signal transduction, and apoptosis. We provide a comprehensive review of protein lipidation, including descriptions of proteins known to be modified and the functions of the modifications, the enzymes that control them, and the tools and technologies developed to study them. We also highlight key questions about protein lipidation that remain to be answered, the challenges associated with answering such questions, and possible solutions to overcome these challenges.
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Affiliation(s)
- Hong Jiang
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Xiaoyu Zhang
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Xiao Chen
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Pornpun Aramsangtienchai
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Zhen Tong
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Hening Lin
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
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29
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Langemeyer L, Perz A, Kümmel D, Ungermann C. A guanine nucleotide exchange factor (GEF) limits Rab GTPase-driven membrane fusion. J Biol Chem 2017; 293:731-739. [PMID: 29184002 DOI: 10.1074/jbc.m117.812941] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 11/14/2017] [Indexed: 11/06/2022] Open
Abstract
The identity of organelles in the endomembrane system of any eukaryotic cell critically depends on the correctly localized Rab GTPase, which binds effectors and thus promotes membrane remodeling or fusion. However, it is still unresolved which factors are required and therefore define the localization of the correct fusion machinery. Using SNARE-decorated proteoliposomes that cannot fuse on their own, we now demonstrate that full fusion activity can be achieved by just four soluble factors: a soluble SNARE (Vam7), a guanine nucleotide exchange factor (GEF, Mon1-Ccz1), a Rab-GDP dissociation inhibitor (GDI) complex (prenylated Ypt7-GDI), and a Rab effector complex (HOPS). Our findings reveal that the GEF Mon1-Ccz1 is necessary and sufficient for stabilizing prenylated Ypt7 on membranes. HOPS binding to Ypt7-GTP then drives SNARE-mediated fusion, which is fully GTP-dependent. We conclude that an entire fusion cascade can be controlled by a GEF.
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Affiliation(s)
| | | | - Daniel Kümmel
- Structural Biochemistry, Department of Biology/Chemistry, University of Osnabrück, Barbarastrasse 13, 49076 Osnabrück, Germany
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30
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Choi J, Kim H, Bae YK, Cheong H. REP1 Modulates Autophagy and Macropinocytosis to Enhance Cancer Cell Survival. Int J Mol Sci 2017; 18:ijms18091866. [PMID: 28846638 PMCID: PMC5618515 DOI: 10.3390/ijms18091866] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 08/21/2017] [Accepted: 08/22/2017] [Indexed: 01/18/2023] Open
Abstract
Rab escort protein 1 (REP1), a component of the Rab geranyl-geranyltransferase 2 complex, plays a role in Rab protein recruitment in proper vesicles during vesicle trafficking. In addition to having well-known tissue degenerative phenotypes in the REP1 mutant, REP1 is tightly associated with cancer development and contributes to cell growth and survival. However, the functional mechanism of REP1 in cancer progression is largely uninvestigated. Here, we show that REP1 plays a crucial role in regulating mammalian target of rapamycin (mTOR) signaling and its downstream pathways, as well as autophagy and macropinocytosis, which are essential for cancer cell survival during metabolic stresses including starvation. REP1 small interfering RNA (siRNA) treatment downregulates mTORC1 activity in growing media, but blocks autophagosome formation under nutrient-depleted conditions. In contrast to the mild decrease of lysosomal enzyme activity seen in REP1 depletion, in REP1 knockdown the subcellular localization of lysosomes is altered, and localization of REP1 itself is modulated by intracellular nutrient levels and mTOR activity. Furthermore, REP1 depletion increases macro pinocytosis which may be a feedback mechanism to compensate autophagy inhibition. Concomitant treatment with macropinocytosis inhibitor and REP1siRNAresults in more significant cell death than autophagy blockade with REP1 knockdown. Therefore, REP1-mediated autophagy and lysosomal degradation processes act as novel regulatory mechanisms to support cancer cell survival, which can be further investigated as a potential cancer-targeting pathway.
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Affiliation(s)
- Jungwon Choi
- Tumor Microenvironment Research Branch, Research Institute, National Cancer Center, 323 Ilsan-ro, Ilsandong-gu,10 Goyang-si, Gyeonggi-do 10408, Korea.
| | - Hyena Kim
- Tumor Microenvironment Research Branch, Research Institute, National Cancer Center, 323 Ilsan-ro, Ilsandong-gu,10 Goyang-si, Gyeonggi-do 10408, Korea.
| | - Young Ki Bae
- Tumor Microenvironment Research Branch, Research Institute, National Cancer Center, 323 Ilsan-ro, Ilsandong-gu,10 Goyang-si, Gyeonggi-do 10408, Korea.
| | - Heesun Cheong
- Tumor Microenvironment Research Branch, Research Institute, National Cancer Center, 323 Ilsan-ro, Ilsandong-gu,10 Goyang-si, Gyeonggi-do 10408, Korea.
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31
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Mulvaney EP, O'Meara F, Khan AR, O'Connell DJ, Kinsella BT. Identification of α-helix 4 (α4) of Rab11a as a novel Rab11-binding domain (RBD): Interaction of Rab11a with the Prostacyclin Receptor. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1864:1819-1832. [PMID: 28739266 DOI: 10.1016/j.bbamcr.2017.07.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 06/28/2017] [Accepted: 07/20/2017] [Indexed: 12/29/2022]
Abstract
The cellular trafficking of numerous G protein-coupled receptors (GPCRs) is known to be regulated by Rab proteins that involves a direct protein:protein interaction between the receptor and the GTPase. In the case of the human prostacyclin receptor (hIP), it undergoes agonist-induced internalization and subsequent Rab11a-dependent recyclization involving an interaction between a Rab11-binding domain (RBD) localized within its carboxyl-tail domain with Rab11a. However, the GPCR-interacting domain on Rab11a itself is unknown. Hence, we sought to identify the region within Rab11a that mediates its interaction with the RBD of the hIP. The α4 helix region of Rab11 was identified as a novel binding domain for the hIP, a site entirely distinct from the Switch I/Switch II -regions that act as specific binding domain for most other Rab and Ras-like GTPase interactants. Specifically, Glu138 within α4 helix of Rab11a appears to contact with key residues (e.g. Lys304) within the RBD of the hIP, where such contacts differ depending on the agonist-activated versus -inactive status of the hIP. Through mutational studies, supported by in silico homology modelling of the inactive and active hIP:Rab11a complexes, a mechanism is proposed to explain both the constitutive and agonist-induced binding of Rab11a to regulate intracellular trafficking of the hIP. Collectively, these studies are not only the first to identify α4 helix of Rab11a as a protein binding domain on the GTPase but also reveal novel mechanistic insights into the intracellular trafficking of the hIP, and potentially of other members of the GPCR superfamily, involving Rab11-dependent mechanisms.
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Affiliation(s)
- Eamon P Mulvaney
- UCD School of Biomolecular and Biomedical Sciences, UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland
| | - Fergal O'Meara
- UCD School of Biomolecular and Biomedical Sciences, UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland
| | - Amir R Khan
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland
| | - David J O'Connell
- UCD School of Biomolecular and Biomedical Sciences, UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland
| | - B Therese Kinsella
- UCD School of Biomolecular and Biomedical Sciences, UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland.
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32
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Vetter IR. Interface analysis of small GTP binding protein complexes suggests preferred membrane orientations. Biol Chem 2017; 398:637-651. [PMID: 28002022 DOI: 10.1515/hsz-2016-0287] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 12/12/2016] [Indexed: 11/15/2022]
Abstract
Crystal structures of small GTP binding protein complexes with their effectors and regulators reveal that one particularly flat side of the G domain that contains helix α4 and the C-terminal helix α5 is practically devoid of contacts. Although this observation seems trivial as the main binding targets are the switch I and II regions opposite of this side, the fact that all interacting proteins, even the largest ones, seem to avoid occupying this area (except for Ran, that does not localize to membranes) is very striking. An orientation with this 'flat' side parallel to the membrane was proposed before and would allow simultaneous interaction of the lipidated C-terminus and positive charges in the α4 helix with the membrane while being bound to effector or regulator molecules. Furthermore, this 'flat' side might be involved in regulatory mechanisms: a Ras dimer that is found in different crystal forms interacts exactly at this side. Additional interface analysis of GTPase complexes nicely confirms the effect of different flexibilities of the GTP and GDP forms. Besides Ran proteins, guanine nucleotide exchange factors (GEFs) bury the largest surface areas to provide the binding energy to open up the switch regions for nucleotide exchange.
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Affiliation(s)
- Ingrid R Vetter
- Max Planck Institute of Molecular Physiology, Department of Mechanistic Cell Biology, Otto-Hahn-Str. 11, D-44227 Dortmund
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33
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Pylypenko O, Hammich H, Yu IM, Houdusse A. Rab GTPases and their interacting protein partners: Structural insights into Rab functional diversity. Small GTPases 2017. [PMID: 28632484 PMCID: PMC5902227 DOI: 10.1080/21541248.2017.1336191] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Rab molecular switches are key players in defining membrane identity and regulating intracellular trafficking events in eukaryotic cells. In spite of their global structural similarity, Rab-family members acquired particular features that allow them to perform specific cellular functions. The overall fold and local sequence conservations enable them to utilize a common machinery for prenylation and recycling; while individual Rab structural differences determine interactions with specific partners such as GEFs, GAPs and effector proteins. These interactions orchestrate the spatiotemporal regulation of Rab localization and their turning ON and OFF, leading to tightly controlled Rab-specific functionalities such as membrane composition modifications, recruitment of molecular motors for intracellular trafficking, or recruitment of scaffold proteins that mediate interactions with downstream partners, as well as actin cytoskeleton regulation. In this review we summarize structural information on Rab GTPases and their complexes with protein partners in the context of partner binding specificity and functional outcomes of their interactions in the cell.
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Affiliation(s)
- Olena Pylypenko
- a Structural Motility, Institut Curie , PSL Research University, CNRS, UMR 144 , Paris , France
| | - Hussein Hammich
- a Structural Motility, Institut Curie , PSL Research University, CNRS, UMR 144 , Paris , France.,b Sorbonne Universités , UPMC Univ Paris 06, Sorbonne Universités, IFD , Paris , France
| | - I-Mei Yu
- a Structural Motility, Institut Curie , PSL Research University, CNRS, UMR 144 , Paris , France
| | - Anne Houdusse
- a Structural Motility, Institut Curie , PSL Research University, CNRS, UMR 144 , Paris , France
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34
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Goody RS, Müller MP, Wu YW. Mechanisms of action of Rab proteins, key regulators of intracellular vesicular transport. Biol Chem 2017; 398:565-575. [DOI: 10.1515/hsz-2016-0274] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 11/08/2016] [Indexed: 11/15/2022]
Abstract
Abstract
Our understanding of the manner in which Rab proteins regulate intracellular vesicular transport has progressed remarkably in the last one or two decades by application of a wide spectrum of biochemical, biophysical and cell biological methods, augmented by the methods of chemical biology. Important additional insights have arisen from examination of the manner in which certain bacteria can manipulate vesicular transport mechanisms. The progress in these areas is summarized here.
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35
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Lindemann C, Thomanek N, Hundt F, Lerari T, Meyer HE, Wolters D, Marcus K. Strategies in relative and absolute quantitative mass spectrometry based proteomics. Biol Chem 2017; 398:687-699. [DOI: 10.1515/hsz-2017-0104] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 02/28/2017] [Indexed: 11/15/2022]
Abstract
Abstract
Quantitative mass spectrometry approaches are used for absolute and relative quantification in global proteome studies. To date, relative and absolute quantification techniques are available that differ in quantification accuracy, proteome coverage, complexity and robustness. This review focuses on most common relative or absolute quantification strategies exemplified by three experimental studies. A label-free relative quantification approach was performed for the investigation of the membrane proteome of sensory cilia to the depth of olfactory receptors in Mus musculus. A SILAC-based relative quantification approach was successfully applied for the identification of core components and transient interactors of the peroxisomal importomer in Saccharomyces cerevisiae. Furthermore, AQUA using stable isotopes was exemplified to unraveling the prenylome influenced by novel prenyltransferase inhibitors. Characteristic enrichment and fragmentation strategies for a robust quantification of the prenylome are also summarized.
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36
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Abstract
Rab GTPases, the highly conserved members of Ras GTPase superfamily are central players in the vesicular trafficking. They are critically involved in intracellular trafficking pathway, beginning from formation of vesicles on donor membranes, defining trafficking specificity to facilitating vesicle docking on target membranes. Given the dynamic roles of Rabs during different stages of vesicular trafficking, mechanisms for their spatial and temporal regulation are crucial for normal cellular function. Regulation of Rab GTPase activity, localization and function has always been focused in and around the association of GDP dissociation inhibitor (GDI), Guanine nucleotide Exchange Factor (GEFs) and GTPase accelerating protein (GAP) to Rabs. However, several recent studies have highlighted the importance of different post-translational modifications in regulation of Rab activation and function. This review provides a summary of various post translational modifications (PTMs) and their significance to regulate localization and function of different Rabs.
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Affiliation(s)
- Swapnil Rohidas Shinde
- a Laboratory of Cell Death & Cell Survival , Centre for DNA Fingerprinting and Diagnostics (CDFD) , Nampally, Hyderabad , India.,b Graduate Studies , Manipal University , Manipal , India
| | - Subbareddy Maddika
- a Laboratory of Cell Death & Cell Survival , Centre for DNA Fingerprinting and Diagnostics (CDFD) , Nampally, Hyderabad , India
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37
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38
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Abstract
Rab proteins are the major regulators of vesicular trafficking in eukaryotic cells. Their activity can be tightly controlled within cells: Regulated by guanine nucleotide exchange factors (GEFs) and GTPase activating proteins (GAPs), they switch between an active GTP-bound state and an inactive GDP-bound state, interacting with downstream effector proteins only in the active state. Additionally, they can bind to membranes via C-terminal prenylated cysteine residues and they can be solubilized and shuttled between membranes by chaperone-like molecules called GDP dissociation inhibitors (GDIs). In this review we give an overview of Rab proteins with a focus on the current understanding of their regulation by GEFs, GAPs and GDI.
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Affiliation(s)
- Matthias P Müller
- a Department of Structural Biochemistry , Max Planck Institute of Molecular Physiology , Dortmund , Germany
| | - Roger S Goody
- a Department of Structural Biochemistry , Max Planck Institute of Molecular Physiology , Dortmund , Germany
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39
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Richardson R, Smart M, Tracey-White D, Webster AR, Moosajee M. Mechanism and evidence of nonsense suppression therapy for genetic eye disorders. Exp Eye Res 2017; 155:24-37. [PMID: 28065590 DOI: 10.1016/j.exer.2017.01.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 11/24/2016] [Accepted: 01/04/2017] [Indexed: 01/09/2023]
Abstract
Between 5 and 70% of genetic disease is caused by in-frame nonsense mutations, which introduce a premature termination codon (PTC) within the disease-causing gene. Consequently, during translation, non-functional or gain-of-function truncated proteins of pathological significance, are formed. Approximately 50% of all inherited retinal disorders have been associated with PTCs, highlighting the importance of novel pharmacological or gene correction therapies in ocular disease. Pharmacological nonsense suppression of PTCs could delineate a therapeutic strategy that treats the mutation in a gene- and disease-independent manner. This approach aims to suppress the fidelity of the ribosome during protein synthesis so that a near-cognate aminoacyl-tRNA, which shares two of the three nucleotides of the PTC, can be inserted into the peptide chain, allowing translation to continue, and a full-length functional protein to be produced. Here we discuss the mechanisms and evidence of nonsense suppression agents, including the small molecule drug ataluren (or PTC124) and next generation 'designer' aminoglycosides, for the treatment of genetic eye disease.
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Affiliation(s)
- Rose Richardson
- Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, UK
| | - Matthew Smart
- Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, UK
| | - Dhani Tracey-White
- Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, UK
| | - Andrew R Webster
- Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, UK; Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Mariya Moosajee
- Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, UK; Moorfields Eye Hospital NHS Foundation Trust, London, UK.
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40
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Song KH, Woo SR, Chung JY, Lee HJ, Oh SJ, Hong SO, Shim J, Kim YN, Rho SB, Hong SM, Cho H, Hibi M, Bae DJ, Kim SY, Kim MG, Kim TW, Bae YK. REP1 inhibits FOXO3-mediated apoptosis to promote cancer cell survival. Cell Death Dis 2017; 8:e2536. [PMID: 28055019 PMCID: PMC5386371 DOI: 10.1038/cddis.2016.462] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 11/29/2016] [Accepted: 12/07/2016] [Indexed: 01/15/2023]
Abstract
Rab escort protein 1 (REP1) is a component of Rab geranyl-geranyl transferase 2 complex. Mutations in REP1 cause a disease called choroideremia (CHM), which is an X-linked eye disease. Although it is postulated that REP1 has functions in cell survival or death of various tissues in addition to the eye, how REP1 functions in normal and cancer cells remains to be elucidated. Here, we demonstrated that REP1 is required for the survival of intestinal cells in addition to eyes or a variety of cells in zebrafish, and also has important roles in tumorigenesis. Notably, REP1 is highly expressed in colon cancer tissues and cell lines, and silencing of REP1 sensitizes colon cancer cells to serum starvation- and 5-FU-induced apoptosis. In an effort to elucidate the molecular mechanisms underlying REP1-mediated cell survival under those stress conditions, we identified FOXO3 as a binding partner of REP1 using a yeast two-hybrid (Y2H) assay system, and we demonstrated that REP1 blocked the nuclear trans-localization of FOXO3 through physically interacting with FOXO3, thereby suppressing FOXO3-mediated apoptosis. Importantly, the inhibition of REP1 combined with 5-FU treatment could lead to significant retarded tumor growth in a xenograft tumor model of human cancer cells. Thus, our results suggest that REP1 could be a new therapeutic target in combination treatment for colon cancer patients.
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Affiliation(s)
- Kwon-Ho Song
- Laboratory of Tumor Immunology, Department of Biomedical Sciences, Graduate School of Medicine, Korea University, Seoul, Republic of Korea.,Department of Biochemistry, Korea University College of Medicine, Seoul, Republic of Korea.,Department of Biomedical Sciences, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Seon Rang Woo
- Laboratory of Tumor Immunology, Department of Biomedical Sciences, Graduate School of Medicine, Korea University, Seoul, Republic of Korea.,Department of Biochemistry, Korea University College of Medicine, Seoul, Republic of Korea.,Translational Research Institute for Incurable Diseases, Korea University College of Medicine, Seoul, Republic of Korea
| | - Joon-Yong Chung
- Experimental Pathology Laboratory, Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Hyo-Jung Lee
- Laboratory of Tumor Immunology, Department of Biomedical Sciences, Graduate School of Medicine, Korea University, Seoul, Republic of Korea.,Department of Biochemistry, Korea University College of Medicine, Seoul, Republic of Korea.,Department of Biomedical Sciences, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Se Jin Oh
- Laboratory of Tumor Immunology, Department of Biomedical Sciences, Graduate School of Medicine, Korea University, Seoul, Republic of Korea.,Department of Biochemistry, Korea University College of Medicine, Seoul, Republic of Korea.,Department of Biomedical Sciences, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Soon-Oh Hong
- Laboratory of Tumor Immunology, Department of Biomedical Sciences, Graduate School of Medicine, Korea University, Seoul, Republic of Korea.,Department of Biochemistry, Korea University College of Medicine, Seoul, Republic of Korea.,Department of Biomedical Sciences, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Jaegal Shim
- Comparative Biomedicine Research Branch, Research Institute, National Cancer Center, Goyang, Republic of Korea
| | - Yong Nyun Kim
- Comparative Biomedicine Research Branch, Research Institute, National Cancer Center, Goyang, Republic of Korea
| | - Seung Bae Rho
- Gynecologic Cancer Branch, Research Institute, National Cancer Center, Goyang, Republic of Korea
| | - Seung-Mo Hong
- Department of Pathology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Republic of Korea
| | - Hanbyoul Cho
- Experimental Pathology Laboratory, Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.,Department of Obstetrics and Gynecology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Masahiko Hibi
- Bioscience and Biotechnology Center, Nagoya University, Nagoya, Japan
| | - Dong-Jun Bae
- ASAN Institute for Life Sciences, ASAN Medical Center, Seoul, Republic of Korea
| | - Sang-Yeob Kim
- ASAN Institute for Life Sciences, ASAN Medical Center, Seoul, Republic of Korea.,Department of Convergence Medicine, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Min Gyu Kim
- School of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Tae Woo Kim
- Laboratory of Tumor Immunology, Department of Biomedical Sciences, Graduate School of Medicine, Korea University, Seoul, Republic of Korea.,Department of Biochemistry, Korea University College of Medicine, Seoul, Republic of Korea.,Department of Biomedical Sciences, College of Medicine, Korea University, Seoul, Republic of Korea.,Translational Research Institute for Incurable Diseases, Korea University College of Medicine, Seoul, Republic of Korea
| | - Young-Ki Bae
- Comparative Biomedicine Research Branch, Research Institute, National Cancer Center, Goyang, Republic of Korea
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41
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Simunovic MP, Jolly JK, Xue K, Edwards TL, Groppe M, Downes SM, MacLaren RE. The Spectrum of CHM Gene Mutations in Choroideremia and Their Relationship to Clinical Phenotype. Invest Ophthalmol Vis Sci 2016; 57:6033-6039. [PMID: 27820636 PMCID: PMC5102569 DOI: 10.1167/iovs.16-20230] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 09/22/2016] [Indexed: 01/17/2023] Open
Abstract
PURPOSE We report the underlying genotype and explore possible genotypic-phenotypic correlations in a large cohort of choroideremia patients. METHODS We studied prospectively a cohort of 79 patients diagnosed within a tertiary referral service for patients with retinal dystrophies. Phenotypic evaluation consisted of clinical examination, including visual acuity and residual retinal area by fundus autofluorescence (FAF). Genotype was established by sequencing. We also investigated whether particular genotypes were associated with more severe phenotypes by performing analysis of covariance (ANCOVA), with visual acuity and FAF as the dependent variables and age as the covariant. RESULTS A total of 74 (94%) of patients in our cohort had causative mutations by sequencing, the majority of which were anticipated to be null. Of these, 35 (47%) had insertions and deletions, 13 (18%) had mutations predicted to affect splicing, and 26 (35%) had single point mutations. In the latter case, 13 of 21 (62%) pedigrees with single point mutations were C to T transitions at C-phosphate-G (CpG) dinucleotides. These mutations were spread across 5 of only 24 CpG dinucleotides in the entire CHM cDNA. Furthermore, these 5 locations are the only sites at which C to T transitions result in a stop codon. No clear evidence was found for genotype-phenotype correlation except in the instance of a patient with a large deletion involving neighbouring sequences. CONCLUSIONS In patients with a diagnosis of choroideremia made by a specialty service, there is a high likelihood of establishing a genetic diagnosis. The majority of causative mutations appear to be null and, therefore, may benefit from gene replacement therapy. A disproportionate number of single point mutations observed were C to T transitions, consistent with the evolutionary decay of CpG dinucleotides through methylation and subsequent deamination. Hence, the development of choroideremia in such patients may represent the unwanted consequence of human evolution; de novo mutations are predicted to arise at these sites in future generations. (ClinicalTrials.gov number, NCT01461213.).
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Affiliation(s)
- Matthew P. Simunovic
- Nuffield Laboratory of Ophthalmology, University of Oxford West Wing, John Radcliffe Hospital, Oxford, United Kingdom
- Oxford Eye Hospital, University of Oxford NHS Trust, West Wing, John Radcliffe Hospital, Oxford, United Kingdom
- Save Sight Institute, Sydney University, Sydney, New South Wales, Australia
- Sydney Eye Hospital, Sydney, New South Wales, Australia
| | - Jasleen K. Jolly
- Nuffield Laboratory of Ophthalmology, University of Oxford West Wing, John Radcliffe Hospital, Oxford, United Kingdom
- Oxford Eye Hospital, University of Oxford NHS Trust, West Wing, John Radcliffe Hospital, Oxford, United Kingdom
| | - Kanmin Xue
- Nuffield Laboratory of Ophthalmology, University of Oxford West Wing, John Radcliffe Hospital, Oxford, United Kingdom
- Oxford Eye Hospital, University of Oxford NHS Trust, West Wing, John Radcliffe Hospital, Oxford, United Kingdom
| | - Thomas L. Edwards
- Nuffield Laboratory of Ophthalmology, University of Oxford West Wing, John Radcliffe Hospital, Oxford, United Kingdom
- Oxford Eye Hospital, University of Oxford NHS Trust, West Wing, John Radcliffe Hospital, Oxford, United Kingdom
| | - Markus Groppe
- Nuffield Laboratory of Ophthalmology, University of Oxford West Wing, John Radcliffe Hospital, Oxford, United Kingdom
- Oxford Eye Hospital, University of Oxford NHS Trust, West Wing, John Radcliffe Hospital, Oxford, United Kingdom
| | - Susan M. Downes
- Nuffield Laboratory of Ophthalmology, University of Oxford West Wing, John Radcliffe Hospital, Oxford, United Kingdom
- Oxford Eye Hospital, University of Oxford NHS Trust, West Wing, John Radcliffe Hospital, Oxford, United Kingdom
| | - Robert E. MacLaren
- Nuffield Laboratory of Ophthalmology, University of Oxford West Wing, John Radcliffe Hospital, Oxford, United Kingdom
- Oxford Eye Hospital, University of Oxford NHS Trust, West Wing, John Radcliffe Hospital, Oxford, United Kingdom
- Moorfields Eye Hospital, London, United Kingdom
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42
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Abstract
A complex endomembrane system is one of the hallmarks of Eukaryotes. Vesicle trafficking between compartments is controlled by a diverse protein repertoire, including Rab GTPases. These small GTP-binding proteins contribute identity and specificity to the system, and by working as molecular switches, trigger multiple events in vesicle budding, transport, and fusion. A diverse collection of Rab GTPases already existed in the ancestral Eukaryote, yet, it is unclear how such elaborate repertoire emerged. A novel archaeal phylum, the Lokiarchaeota, revealed that several eukaryotic-like protein systems, including small GTPases, are present in Archaea. Here, we test the hypothesis that the Rab family of small GTPases predates the origin of Eukaryotes. Our bioinformatic pipeline detected multiple putative Rab-like proteins in several archaeal species. Our analyses revealed the presence and strict conservation of sequence features that distinguish eukaryotic Rabs from other small GTPases (Rab family motifs), mapping to the same regions in the structure as in eukaryotic Rabs. These mediate Rab-specific interactions with regulators of the REP/GDI (Rab Escort Protein/GDP dissociation Inhibitor) family. Sensitive structure-based methods further revealed the existence of REP/GDI-like genes in Archaea, involved in isoprenyl metabolism. Our analysis supports a scenario where Rabs differentiated into an independent family in Archaea, interacting with proteins involved in membrane biogenesis. These results further support the archaeal nature of the eukaryotic ancestor and provide a new insight into the intermediate stages and the evolutionary path toward the complex membrane-associated signaling circuits that characterize the Ras superfamily of small GTPases, and specifically Rab proteins.
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43
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Moosajee M, Tracey-White D, Smart M, Weetall M, Torriano S, Kalatzis V, da Cruz L, Coffey P, Webster AR, Welch E. Functional rescue of REP1 following treatment with PTC124 and novel derivative PTC-414 in human choroideremia fibroblasts and the nonsense-mediated zebrafish model. Hum Mol Genet 2016; 25:3416-3431. [DOI: 10.1093/hmg/ddw184] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2016] [Revised: 06/03/2016] [Accepted: 06/06/2016] [Indexed: 01/15/2023] Open
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44
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Shinde SR, Maddika S. A modification switch on a molecular switch: Phosphoregulation of Rab7 during endosome maturation. Small GTPases 2016; 7:164-7. [PMID: 27070490 DOI: 10.1080/21541248.2016.1175539] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Rab GTPases, the highly conserved members of Ras GTPase superfamily are the pivotal regulators of vesicle-mediated trafficking. Rab GTPases, each with a specific subcellular localization, exert tremendous control over various aspects of vesicular transport, identity and dynamics. Several lines of research have established that GDI, GEFs and GAPs are the critical players to orchestrate Rab GTPase activity and function. The importance of post translational modifications in Rab GTPase functional regulation is poorly or not yet been addressed except for prenylation. Our recent study has revealed a novel dephosphorylation dependent regulatory mechanism for Rab7 activity and function. We have shown the importance of PTEN mediated dephosphorylation of Rab7 on highly conserved S72 and Y183 residues, which is essential for its GDI mediated membrane targeting and further activation by GEF. In conclusion, our study highlighted the importance of a phosphorylation/dephosphorylation switch in controlling timely Rab7 localization and activity on endosomes.
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Affiliation(s)
- Swapnil Rohidas Shinde
- a Laboratory of Cell Death & Cell Survival, Centre for DNA Fingerprinting and Diagnostics (CDFD), Nampally , Hyderabad , India.,b Graduate Studies, Manipal University , Manipal , India
| | - Subbareddy Maddika
- a Laboratory of Cell Death & Cell Survival, Centre for DNA Fingerprinting and Diagnostics (CDFD), Nampally , Hyderabad , India
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45
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Shinde SR, Maddika S. PTEN modulates EGFR late endocytic trafficking and degradation by dephosphorylating Rab7. Nat Commun 2016; 7:10689. [PMID: 26869029 PMCID: PMC4754336 DOI: 10.1038/ncomms10689] [Citation(s) in RCA: 104] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 01/08/2016] [Indexed: 01/09/2023] Open
Abstract
Tumour suppressor phosphatase and tensin homologue deleted on chromosome 10 (PTEN) is a lipid phosphatase that negatively regulates growth factor-induced survival signalling. Here, we demonstrate that PTEN attenuates epidermal growth factor receptor (EGFR) signalling by promoting late endosome maturation by virtue of its protein phosphatase activity. Loss of PTEN impairs the transition of ligand-bound EGFR from early to late endosomes. We unveil Rab7, a critical GTPase for endosome maturation, as a functional PTEN interacting partner. PTEN dephosphorylates Rab7 on two conserved residues S72 and Y183, which are necessary for GDP dissociation inhibitor (GDI)-dependent recruitment of Rab7 on to late endosomes and subsequent maturation. Thus, our findings reveal PTEN-dependent endosome maturation through phosphoregulation of Rab7 as an important route of controlling EGFR signalling. Rab7 is a critical GTPase for endosome maturation and it is implicated in the endocytic traffic of several receptors, including EGFR. In this study, the authors reveal the potential role of PTEN in the endocytic trafficking pathway of EGFR, which is dependent on its phosphatase activity through the direct post-translational modification of Rab7.
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Affiliation(s)
- Swapnil Rohidas Shinde
- Laboratory of Cell Death and Cell Survival, Centre for DNA Fingerprinting and Diagnostics (CDFD), Nampally, Hyderabad 500001, India.,Graduate Studies, Manipal University, Manipal 576104, India
| | - Subbareddy Maddika
- Laboratory of Cell Death and Cell Survival, Centre for DNA Fingerprinting and Diagnostics (CDFD), Nampally, Hyderabad 500001, India
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46
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Wang YC, Distefano MD. Synthetic isoprenoid analogues for the study of prenylated proteins: Fluorescent imaging and proteomic applications. Bioorg Chem 2016; 64:59-65. [PMID: 26709869 PMCID: PMC4731301 DOI: 10.1016/j.bioorg.2015.12.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 12/01/2015] [Accepted: 12/10/2015] [Indexed: 01/09/2023]
Abstract
Protein prenylation is a posttranslational modification catalyzed by prenyltransferases involving the attachment of farnesyl or geranylgeranyl groups to residues near the C-termini of proteins. This irreversible covalent modification is important for membrane localization and proper signal transduction. Here, the use of isoprenoid analogues for studying prenylated proteins is reviewed. First, experiments with analogues containing small fluorophores that are alternative substrates for prenyltransferases are described. Those analogues have been useful for quantifying binding affinity and for the production of fluorescently labeled proteins. Next, the use of analogues that incorporate biotin, bioorthogonal groups or antigenic moieties is described. Such probes have been particularly useful for identifying proteins that are naturally prenylated within mammalian cells. Overall, the use of isoprenoid analogues has contributed significantly to the understanding of protein prenlation.
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Affiliation(s)
- Yen-Chih Wang
- Departments of Chemistry and Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - Mark D Distefano
- Departments of Chemistry and Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, USA.
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47
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Mascia A, Gentile F, Izzo A, Mollo N, De Luca M, Bucci C, Nitsch L, Calì G. Rab7 Regulates CDH1 Endocytosis, Circular Dorsal Ruffles Genesis, and Thyroglobulin Internalization in a Thyroid Cell Line. J Cell Physiol 2015; 231:1695-708. [PMID: 26599499 DOI: 10.1002/jcp.25267] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 11/23/2015] [Indexed: 01/02/2023]
Abstract
Rab7 regulates the biogenesis of late endosomes, lysosomes, and autophagosomes. It has been proposed that a functional and physical interaction exists between Rab7 and Rac1 GTPases in CDH1 endocytosis and ruffled border formation. In FRT cells over-expressing Rab7, increased expression and activity of Rac1 was observed, whereas a reduction of Rab7 expression by RNAi resulted in reduced Rac1 activity, as measured by PAK1 phosphorylation. We found that CDH1 endocytosis was extremely reduced only in Rab7 over-expressing cells but was unchanged in Rab7 silenced cells. In Rab7 under or over-expressing cells, Rab7 and LC3B-II co-localized and co-localization in large circular structures occurred only in Rab7 over-expressing cells. These large circular structures occurred in about 10% of the cell population; some of them (61%) showed co-localization of Rab7 with cortactin and f-actin and were identified as circular dorsal ruffles (CDRs), the others as mature autophagosomes. We propose that the over-expression of Rab7 is sufficient to induce CDRs. Furthermore, in FRT cells, we found that the expression of the insoluble/active form of Rab7, rather than Rab5, or Rab8, was inducible by cAMP and that cAMP-stimulated FRT cells showed increased PAK1 phosphorylation and were no longer able to endocytose CDH1. Finally, we demonstrated that Rab7 over-expressing cells are able to endocytose exogenous thyroglobulin via pinocytosis/CDRs more efficiently than control cells. We propose that the major thyroglobulin endocytosis described in thyroid autonomous adenomas due to Rab7 increased expression, occurs via CDRs. J. Cell. Physiol. 231: 1695-1708, 2016. © 2015 Wiley Periodicals, Inc.
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Affiliation(s)
- Anna Mascia
- IEOS Istituto di Endocrinologia e Oncologia Sperimentale "G. Salvatore", National Council of Research, Napoli, Italy
| | - Flaviana Gentile
- IEOS Istituto di Endocrinologia e Oncologia Sperimentale "G. Salvatore", National Council of Research, Napoli, Italy
| | - Antonella Izzo
- Department of Molecular Medicine and Medical Biotechnologies, University "Federico II", Napoli, Italy
| | - Nunzia Mollo
- Department of Molecular Medicine and Medical Biotechnologies, University "Federico II", Napoli, Italy
| | - Maria De Luca
- Department of Biological and Environmental Sciences and Technologies, University of Salento (DiSTeBA), Lecce, Italy
| | - Cecilia Bucci
- Department of Biological and Environmental Sciences and Technologies, University of Salento (DiSTeBA), Lecce, Italy
| | - Lucio Nitsch
- Department of Molecular Medicine and Medical Biotechnologies, University "Federico II", Napoli, Italy
| | - Gaetano Calì
- IEOS Istituto di Endocrinologia e Oncologia Sperimentale "G. Salvatore", National Council of Research, Napoli, Italy
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48
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Dauter Z, Wlodawer A. On the accuracy of unit-cell parameters in protein crystallography. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2015; 71:2217-26. [PMID: 26527139 PMCID: PMC4631477 DOI: 10.1107/s1399004715015503] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2015] [Accepted: 08/19/2015] [Indexed: 11/10/2022]
Abstract
The availability in the Protein Data Bank (PDB) of a number of structures that are presented in space group P1 but in reality possess higher symmetry allowed the accuracy and precision of the unit-cell parameters of the crystals of macromolecules to be evaluated. In addition, diffraction images from crystals of several proteins, previously collected as part of in-house projects, were processed independently with three popular software packages. An analysis of the results, augmented by published serial crystallography data, suggests that the apparent precision of the presentation of unit-cell parameters in the PDB to three decimal points is not justified, since these parameters are subject to errors of not less than 0.2%. It was also noticed that processing data including full crystallographic symmetry does not lead to deterioration of the refinement parameters; thus, it is not beneficial to treat the crystals as belonging to space group P1 when higher symmetry can be seen.
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Affiliation(s)
- Zbigniew Dauter
- Synchrotron Radiation Research Section, MCL, National Cancer Institute, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Alexander Wlodawer
- Protein Structure Section, MCL, National Cancer Institute, Frederick, MD 21702, USA
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49
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Kim CM, Choi JY, Yoon JH, Park HH. Purification, crystallization and X-ray crystallographic analysis of human RAB11(S20V), a constitutively active GTP-binding form. ACTA CRYSTALLOGRAPHICA SECTION F-STRUCTURAL BIOLOGY COMMUNICATIONS 2015; 71:1247-50. [PMID: 26457514 DOI: 10.1107/s2053230x15015447] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 08/18/2015] [Indexed: 11/10/2022]
Abstract
RAB11, a member of the Ras superfamily of small G proteins, is involved in the regulation of vesicle trafficking during endosome recycling. Substitution of Ser20 by Val20 in Rab11 [RAB11(S20V)] inhibits its GTP hydrolysis activity and produces a constitutively active GTP-binding form. In this study, the RAB11(S20V) mutant was overexpressed in Escherichia coli with an engineered C-terminal His tag. RAB11(S20V) was then purified to homogeneity and was crystallized at 293 K. X-ray diffraction data were collected to a resolution of 2.4 Å from a crystal belonging to space group I4, with unit-cell parameters a = 74.11, b = 74.11, c = 149.44 Å. The asymmetric unit was estimated to contain two molecules of RAB11(S20V).
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Affiliation(s)
- Chang Min Kim
- Department of Biochemistry, Yeungnam University, Gyeongsan, Republic of Korea
| | - Jae Young Choi
- Department of Biochemistry, Yeungnam University, Gyeongsan, Republic of Korea
| | - Jong Hwan Yoon
- Department of Biochemistry, Yeungnam University, Gyeongsan, Republic of Korea
| | - Hyun Ho Park
- Department of Biochemistry, Yeungnam University, Gyeongsan, Republic of Korea
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50
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Wiegandt D, Vieweg S, Hofmann F, Koch D, Li F, Wu YW, Itzen A, Müller MP, Goody RS. Locking GTPases covalently in their functional states. Nat Commun 2015; 6:7773. [PMID: 26178622 PMCID: PMC4518245 DOI: 10.1038/ncomms8773] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 06/09/2015] [Indexed: 11/29/2022] Open
Abstract
GTPases act as key regulators of many cellular processes by switching between active (GTP-bound) and inactive (GDP-bound) states. In many cases, understanding their mode of action has been aided by artificially stabilizing one of these states either by designing mutant proteins or by complexation with non-hydrolysable GTP analogues. Because of inherent disadvantages in these approaches, we have developed acryl-bearing GTP and GDP derivatives that can be covalently linked with strategically placed cysteines within the GTPase of interest. Binding studies with GTPase-interacting proteins and X-ray crystallography analysis demonstrate that the molecular properties of the covalent GTPase–acryl–nucleotide adducts are a faithful reflection of those of the corresponding native states and are advantageously permanently locked in a defined nucleotide (that is active or inactive) state. In a first application, in vivo experiments using covalently locked Rab5 variants provide new insights into the mechanism of correct intracellular localization of Rab proteins. The cellular function of small GTPases is regulated by switching between active (GTP-bound) and inactive (GDP-bound) states. Here the authors develop nucleotide analogues that can be covalently linked to GTPases via a strategically placed cysteine residue to lock the target GTPase in defined activation states.
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Affiliation(s)
- David Wiegandt
- Department of Physical Biochemistry, Max Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany
| | - Sophie Vieweg
- Department of Physical Biochemistry, Max Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany
| | - Frank Hofmann
- Department of Physical Biochemistry, Max Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany
| | - Daniel Koch
- Department of Physical Biochemistry, Max Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany
| | - Fu Li
- 1] Department of Physical Biochemistry, Max Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany [2] Chemical Genomics Centre of the Max Planck Society, Otto-Hahn-Strasse 15, 44227 Dortmund, Germany
| | - Yao-Wen Wu
- 1] Department of Physical Biochemistry, Max Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany [2] Chemical Genomics Centre of the Max Planck Society, Otto-Hahn-Strasse 15, 44227 Dortmund, Germany
| | - Aymelt Itzen
- Center for Integrated Protein Science Munich (CIPSM), Department Chemistry, Technische Universität München, Lichtenbergstrasse 4, 85747 Garching, Germany
| | - Matthias P Müller
- Department of Physical Biochemistry, Max Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany
| | - Roger S Goody
- Department of Physical Biochemistry, Max Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany
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