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Chang YC, Li CH, Chan MH, Fang CY, Zhang ZX, Chen CL, Hsiao M. Overexpression of synaptic vesicle protein Rab GTPase 3C promotes vesicular exocytosis and drug resistance in colorectal cancer cells. Mol Oncol 2023; 17:422-444. [PMID: 36652260 PMCID: PMC9980308 DOI: 10.1002/1878-0261.13378] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 11/21/2022] [Accepted: 01/16/2023] [Indexed: 01/19/2023] Open
Abstract
Rab GTPase 3C (RAB3C) is a peripheral membrane protein that is involved in membrane trafficking (vesicle formation) and cell movement. Recently, researchers have noted the exocytosis of RAB proteins, and their dysregulation is correlated with drug resistance and the altered tumor microenvironment in tumorigenesis. However, the molecular mechanisms of exocytotic RABs in the carcinogenicity of colorectal cancer (CRC) remain unknown. Researchers have used various in silico datasets to evaluate the expression profiles of RAB family members. We confirmed that RAB3C plays a key role in CRC progression. Its overexpression promotes exocytosis and is related to the resistance to several chemotherapeutic drugs. We established a proteomic dataset based on RAB3C, and found that dystrophin is one of the proteins that is upregulated with the overexpression of RAB3C. According to our results, RAB3C-induced dystrophin expression promotes vesicle formation and packaging. A connectivity map predicted that the cannabinoid receptor 2 (CB2) agonists reverse RAB3C-associated drug resistance, and that these agonists have synergistic effects when combined with standard chemotherapy regimens. Moreover, we found high dystrophin expression levels in CRC patients with poor survival outcomes. A combination of the dystrophin and RAB3C expression profiles can serve as an independent prognostic factor in CRC and is associated with several clinicopathological parameters. In addition, the RAB3C-dystrophin axis is positively correlated with the phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit alpha isoform (PIK3CA) genetic alterations in CRC patients. These findings can be used to provide novel combined therapeutic options for the treatment of CRC.
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Affiliation(s)
- Yu-Chan Chang
- Department of Biomedical Imaging and Radiological Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Chien-Hsiu Li
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | - Ming-Hsien Chan
- Department of Biomedical Imaging and Radiological Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Chih-Yeu Fang
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli, Taiwan
| | - Zhi-Xuan Zhang
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | - Chi-Long Chen
- Department of Pathology, Taipei Medical University Hospital and College of Medicine, Taipei Medical University, Taiwan
| | - Michael Hsiao
- Genomics Research Center, Academia Sinica, Taipei, Taiwan.,Department and Graduate Institute of Veterinary Medicine, School of Veterinary Medicine, National Taiwan University, Taipei, Taiwan
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Fatty Acid Synthase Is Involved in Classical Swine Fever Virus Replication by Interaction with NS4B. J Virol 2021; 95:e0078121. [PMID: 34132567 DOI: 10.1128/jvi.00781-21] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Classical swine fever virus (CSFV), a member of the genus Pestivirus of the family Flaviviridae, relies on host machinery to complete its life cycle. Previous studies have shown a close connection between virus infection and fatty acid biosynthesis, mainly regulated by fatty acid synthase (FASN). However, the molecular action of how FASN participates in CSFV replication remains to be elucidated. In this study, two chemical inhibitors of the fatty acid synthesis pathway [5-(tetradecyloxy)-2-furoic acid (TOFA) and tetrahydro-4-methylene-2R-octyl-5-oxo-3S-furancarboxylic acid (C75)] significantly impaired the late stage of viral propagation, suggesting CSFV replication required fatty acid synthesis. We next found that CSFV infection stimulated the expression of FASN, whereas knockdown of FASN inhibited CSFV replication. Furthermore, confocal microscopy showed that FASN participated in the formation of replication complex (RC), which was associated with the endoplasmic reticulum (ER). Interestingly, CSFV NS4B interacted with FASN and promoted overexpression of FASN, which is regulated by functional Rab18. Moreover, we found that FASN regulated the formation of lipid droplets (LDs) upon CSFV infection, promoting virus proliferation. Taken together, our work provides mechanistic insight into the role of FASN in the viral life of CSFV, and it highlights the potential antiviral target for the development of therapeutics against pestiviruses. IMPORTANCE Classical swine fever, caused by classical swine fever virus (CSFV), is one of the notifiable diseases by the World Organization for Animal Health (OIE) and causes significant financial losses to the pig industry globally. CSFV, like other (+)-strand RNA viruses, requires lipid and sterol biosynthesis for efficient replication. However, the role of lipid metabolism in CSFV replication remains unknown. Here, we found that fatty acid synthase (FASN) was involved in viral propagation. Moreover, FASN is recruited to CSFV replication sites in the endoplasmic reticulum (ER) and interacts with NS4B to regulate CSFV replication that requires Rab18. Furthermore, we speculated that lipid droplet (LD) biosynthesis, indirectly regulated by FASN, ultimately promotes CSFV replication. Our results highlight a critical role for de novo fatty acid synthesis in CSFV infection, which might help control this devastating virus.
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Antiparasitic dibenzalacetone inhibits the GTPase activity of Rab6 protein of Leishmania donovani (LdRab6), a potential target for its antileishmanial effect. Parasitol Res 2020; 119:2991-3003. [PMID: 32748038 DOI: 10.1007/s00436-020-06810-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 07/08/2020] [Indexed: 10/23/2022]
Abstract
Visceral leishmaniasis (VL, also known as kala-azar) is a vector borne disease caused by obligate intracellular protozoan parasite Leishmania donovani. To overcome the limitations of currently available drugs for VL, molecular target-based study is a promising tool to develop new drugs to treat this neglected tropical disease. One such target we recently identified from L. donovani (Ld) genome (WGS, clinical Indian isolate; BHU 1220, AVPQ01000001) is a small GTP-binding protein, Rab6 protein. We now report a specific inhibitor of the GTPase activity of Rab6 protein of L. donovani (LdRab6) without restricting host enzyme activity. First, to understand the nature of LdRab6 protein, we generated recombinant LdRab6 mutant proteins (rLdRab6) by systematically introducing deletion (two cysteine residues at C-terminal) and mutations [single amino acid substitutions in the conserved region of GTP (Q84L)/GDP(T38N) coding sequence]. The GTPase activity of rLdRab6:GTP and rLdRab6:GDP locked mutant proteins showed ~ 8-fold and ~ 1.5-fold decreases in enzyme activity, respectively, compared to the wild type enzyme activity. The mutant protein rLdRab6:ΔC inhibited the GTPase activity. Sequence alignment analysis of Rab6 protein of L. donovani with Homo sapiens showed identical amino acids in the G conserved region (GTP/GDP-binding sites) but it differed in the C-terminal region. We then evaluated the inhibitory activity of trans-dibenzalacetone (DBA, a synthetic analog of curcumin with strong antileishmanial activity reported earlier by us) in the GTPase activity of LdRab6 protein. Comparative molecular docking analysis of DBA and specific inhibitors of Rab proteins (Lovastatin, BFA, Zoledronate, and NE10790) indicated that DBA had optimum binding affinity with LdRab6 protein. This was further confirmed by the GTPase activity of DBA-treated LdRab6 which showed a basal GTP level significantly lower than that of the wild-type rLdRab6. The results confirm that DBA inhibits the GTPase activity of LdRab6 protein from L. donovani (LdRab6), a potential target for its antileishmanial effect.
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Wang Y, Sheng Y, Liu Y, Zhang W, Cheng T, Duan L, Pan B, Qiao Y, Liu Y, Gao S. A distinct class of eukaryotic MT-A70 methyltransferases maintain symmetric DNA N6-adenine methylation at the ApT dinucleotides as an epigenetic mark associated with transcription. Nucleic Acids Res 2020; 47:11771-11789. [PMID: 31722409 PMCID: PMC7145601 DOI: 10.1093/nar/gkz1053] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Revised: 10/21/2019] [Accepted: 10/24/2019] [Indexed: 12/18/2022] Open
Abstract
Rediscovered as a potential eukaryotic epigenetic mark, DNA N6-adenine methylation (6mA) varies across species in abundance and its relationships with transcription. Here we characterize AMT1—representing a distinct MT-A70 family methyltransferase—in the ciliate Tetrahymena thermophila. AMT1 loss-of-function leads to severe defects in growth and development. Single Molecule, Real-Time (SMRT) sequencing reveals that AMT1 is required for the bulk of 6mA and all symmetric methylation at the ApT dinucleotides. The detection of hemi-methylated ApT sites suggests a semi-conservative mechanism for maintaining symmetric methylation. AMT1 affects expression of many genes; in particular, RAB46, encoding a Rab family GTPase involved in contractile vacuole function, is likely a direct target. The distribution of 6mA resembles H3K4 methylation and H2A.Z, two conserved epigenetic marks associated with RNA polymerase II transcription. Furthermore, strong 6mA and nucleosome positioning in wild-type cells is attenuated in ΔAMT1 cells. Our results support that AMT1-catalyzed 6mA is an integral part of the transcription-associated epigenetic landscape. AMT1 homologues are generally found in protists and basal fungi featuring ApT hyper-methylation associated with transcription, which are missing in animals, plants, and true fungi. This dichotomy of 6mA functions and the underlying molecular mechanisms may have implications in eukaryotic diversification.
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Affiliation(s)
- Yuanyuan Wang
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266003, China.,MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Yalan Sheng
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266003, China.,MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Yongqiang Liu
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266003, China.,MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Wenxin Zhang
- School of Life Science, Anhui Agricultural University, Hefei 230036, China
| | - Ting Cheng
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266003, China.,MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Lili Duan
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266003, China.,MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Bo Pan
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266003, China.,MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Yu Qiao
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266003, China.,MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Yifan Liu
- Department of Pathology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Shan Gao
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266003, China.,MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
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5
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Coppola U, Ristoratore F, Albalat R, D'Aniello S. The evolutionary landscape of the Rab family in chordates. Cell Mol Life Sci 2019; 76:4117-4130. [PMID: 31028425 PMCID: PMC11105323 DOI: 10.1007/s00018-019-03103-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 03/29/2019] [Accepted: 04/10/2019] [Indexed: 12/30/2022]
Abstract
Intracellular traffic amongst organelles represents a key feature for eukaryotes and is orchestrated principally by members of Rab family, the largest within Ras superfamily. Given that variations in Rab repertoire have been fundamental in animal diversification, we provided the most exhaustive survey regarding the Rab toolkit of chordates. Our findings reveal the existence of 42 metazoan conserved subfamilies exhibiting a univocal intron/exon structure preserved from cnidarians to vertebrates. Since the current view does not capture the Rab complexity, we propose a new Rab family classification in three distinct monophyletic clades. The Rab complement of chordates shows a dramatic diversification due to genome duplications and independent gene duplications and losses with sharp differences amongst cephalochordates, tunicates and gnathostome vertebrates. Strikingly, the analysis of the domain architecture of this family highlighted the existence of chimeric calcium-binding Rabs, which are animal novelties characterized by a complex evolutionary history in gnathostomes and whose role in cellular metabolism is obscure. This work provides novel insights in the knowledge of Rab family: our hypothesis is that chordates represent a hotspot of Rab variability, with many events of gene gains and losses impacting intracellular traffic capabilities. Our results help to elucidate the role of Rab members in the transport amongst endomembranes and shed light on intracellular traffic routes in vertebrates. Then, since the predominant role of Rabs in the molecular communication between different cellular districts, this study paves to way to comprehend inherited or acquired human disorders provoked by dysfunctions in Rab genes.
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Affiliation(s)
- Ugo Coppola
- Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn Napoli, Villa Comunale 1, 80121, Naples, Italy
- Molecular Cardiovascular Biology Division, Cincinnati Children's Hospital Medical Center, Cincinnati, USA
| | - Filomena Ristoratore
- Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn Napoli, Villa Comunale 1, 80121, Naples, Italy
| | - Ricard Albalat
- Departament de Genètica, Microbiologia i Estadística and Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Av. Diagonal 643, 08028, Barcelona, Spain.
| | - Salvatore D'Aniello
- Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn Napoli, Villa Comunale 1, 80121, Naples, Italy.
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Yun JS, Ha SC, Kim S, Kim YG, Kim H, Chang JH. Crystal structure of Arabidopsis thaliana RabA1a. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2019; 61:93-109. [PMID: 30010245 DOI: 10.1111/jipb.12700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 07/11/2018] [Indexed: 06/08/2023]
Abstract
RabGTPase is a member of the Ras superfamily of small GTPases, which share a GTP-binding pocket containing highly conserved motifs that promote GTP hydrolysis. In Arabidopsis, the RabA group, which corresponds to the Rab11 group in animals, functions in the recycling of endosomes that control docking and fusion during vesicle transport. However, their molecular mechanisms remain unknown. In this study, we determined the crystal structures of the GDP-bound inactive form and both GppNHp- and GTP-bound active forms of RabA1a, at resolutions of 2.8, 2.6, and 2.6 Å, respectively. A bound sulfate ion in the active site of the GDP-bound structure stabilized Switch II by bridging the interaction between a magnesium ion and Arg74. Comparisons of the two states of RabA1a with Rab11 proteins revealed clear differences in the Switch I and II loops. These results suggested that conformational change of the Switch regions of RabA1a, derived by GTP or GDP binding, could maintain subcellular membrane traffic through the specific interaction of effector molecules.
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Affiliation(s)
- Ji-Sook Yun
- Department of Biology Education, Kyungpook National University, Daehak-ro 80, Daegu 41566, South Korea
| | - Sung Chul Ha
- Beamline Science Division, Pohang Accelerator Laboratory, Jigok-ro 127, Pohang 37673, South Korea
| | - Shinae Kim
- Department of Biology Education, Kyungpook National University, Daehak-ro 80, Daegu 41566, South Korea
| | - Yeon-Gil Kim
- Beamline Science Division, Pohang Accelerator Laboratory, Jigok-ro 127, Pohang 37673, South Korea
| | - Hyeran Kim
- Department of Biological Sciences, Kangwon National University, Kangwondaehak-gil 1, Chuncheon 24341, South Korea
| | - Jeong Ho Chang
- Department of Biology Education, Kyungpook National University, Daehak-ro 80, Daegu 41566, South Korea
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Osanai K. Rab38 Mutation and the Lung Phenotype. Int J Mol Sci 2018; 19:E2203. [PMID: 30060521 PMCID: PMC6122074 DOI: 10.3390/ijms19082203] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2018] [Revised: 07/21/2018] [Accepted: 07/23/2018] [Indexed: 12/12/2022] Open
Abstract
Rab38 is highly expressed in alveolar type II cells, melanocytes, and platelets. These cells are specifically-differentiated cells and contain characteristic intracellular organelles called lysosome-related organelles, i.e., lamellar bodies in alveolar type II cells, melanosomes in melanocytes, and dense granules in platelets. There are Rab38-mutant rodents, i.e., chocolate mice and Ruby rats. While chocolate mice only show oculocutaneous albinism, Ruby rats show oculocutaneous albinism and prolonged bleeding time and, hence, are a rat model of Hermansky-Pudlak syndrome (HPS). Most patients with HPS suffer from fatal interstitial pneumonia by middle age. The lungs of both chocolate mice and Ruby rats show remarkably increased amounts of lung surfactant and conspicuously enlarged lysosome-related organelles, i.e., lamellar bodies, which are also characteristic of the lungs in human HPS. There are 16 mutant HPS-mouse strains, of which ten mutant genes have been identified to be causative in patients with HPS thus far. The gene products of eight of the ten genes constitute one of the three protein complexes, i.e., biogenesis of lysosome-related organelle complex-1, -2, -3 (BLOC-1, -2, -3). Patients with HPS of the mutant BLOC-3 genotype develop interstitial pneumonia. Recently, BLOC-3 has been elucidated to be a guanine nucleotide exchange factor for Rab38. Growing evidence suggests that Rab38 is an additional candidate gene of human HPS that displays the lung phenotype.
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Affiliation(s)
- Kazuhiro Osanai
- Department of Life Science, Medical Research Institute, Kanazawa Medical University, 1-1 Uchinada-Daigaku, Kahokugun, Ishikawa 920-0293, Japan.
- Department of Respiratory Medicine, Kanazawa Medical University, 1-1 Uchinada-Daigaku, Kahokugun, Ishikawa 920-0293, Japan.
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Raza S, Alvisi G, Shahin F, Husain U, Rabbani M, Yaqub T, Anjum AA, Sheikh AA, Nawaz M, Ali MA. Role of Rab GTPases in HSV-1 infection: Molecular understanding of viral maturation and egress. Microb Pathog 2018; 118:146-153. [PMID: 29551438 DOI: 10.1016/j.micpath.2018.03.028] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 03/14/2018] [Accepted: 03/15/2018] [Indexed: 12/17/2022]
Abstract
Most enveloped viruses exploit complex cellular pathways for assembly and egress from the host cell, and the large DNA virus Herpes simplex virus 1 (HSV-1) makes no exception, hijacking several cellular transport pathways for its glycoprotein trafficking and maturation, as well as for viral morphogenesis and egress according to the envelopment, de-envelopment and re-envelopment model. Importantly Rab GTPases, widely distributed master regulators of intracellular membrane trafficking pathways, have recently being tightly implicated in such process. Indeed, siRNA-mediated genetic ablation of specific Rab proteins differently affected HSV-1 production, suggesting a complex role of different Rab proteins in HSV-1 life cycle. In this review, we discuss how different Rabs can regulate HSV-1 assembly/egress and the potential therapeutic applications of such findings for the management of HSV-1 infections.
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Affiliation(s)
- Sohail Raza
- Department of Microbiology, University of Veterinary and Animal Sciences Lahore 54000, Pakistan.
| | - Gualtiero Alvisi
- Department of Molecular Medicine, University of Padua, 35121, Italy
| | - Farzana Shahin
- The State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
| | - Urooj Husain
- Postgraduate Medical Institute Lahore 54000, Pakistan
| | - Masood Rabbani
- Department of Microbiology, University of Veterinary and Animal Sciences Lahore 54000, Pakistan
| | - Tahir Yaqub
- Department of Microbiology, University of Veterinary and Animal Sciences Lahore 54000, Pakistan
| | - Aftab Ahmad Anjum
- Department of Microbiology, University of Veterinary and Animal Sciences Lahore 54000, Pakistan
| | - Ali Ahmad Sheikh
- Department of Microbiology, University of Veterinary and Animal Sciences Lahore 54000, Pakistan
| | - Muhammad Nawaz
- Department of Microbiology, University of Veterinary and Animal Sciences Lahore 54000, Pakistan
| | - Muhammad Asad Ali
- Department of Microbiology, University of Veterinary and Animal Sciences Lahore 54000, Pakistan
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Lukman S, Nguyen MN, Sim K, Teo JCM. Discovery of Rab1 binding sites using an ensemble of clustering methods. Proteins 2017; 85:859-871. [PMID: 28120477 DOI: 10.1002/prot.25254] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 12/28/2016] [Accepted: 01/19/2017] [Indexed: 12/29/2022]
Abstract
Targeting non-native-ligand binding sites for potential investigative and therapeutic applications is an attractive strategy in proteins that share common native ligands, as in Rab1 protein. Rab1 is a subfamily member of Rab proteins, which are members of Ras GTPase superfamily. All Ras GTPase superfamily members bind to native ligands GTP and GDP, that switch on and off the proteins, respectively. Rab1 is physiologically essential for autophagy and transport between endoplasmic reticulum and Golgi apparatus. Pathologically, Rab1 is implicated in human cancers, a neurodegenerative disease, cardiomyopathy, and bacteria-caused infectious diseases. We have performed structural analyses on Rab1 protein using a unique ensemble of clustering methods, including multi-step principal component analysis, non-negative matrix factorization, and independent component analysis, to better identify representative Rab1 proteins than the application of a single clustering method alone does. We then used the identified representative Rab1 structures, resolved in multiple ligand states, to map their known and novel binding sites. We report here at least a novel binding site on Rab1, involving Rab1-specific residues that could be further explored for the rational design and development of investigative probes and/or therapeutic small molecules against the Rab1 protein. Proteins 2017; 85:859-871. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Suryani Lukman
- Khalifa University, Abu Dhabi Campus, PO Box, 127788, Abu Dhabi, United Arab Emirates
| | - Minh N Nguyen
- Bioinformatics Institute, Agency for Science, Technology and Research, 30 Biopolis Street, #07-01 Matrix, Singapore, 138671, Singapore
| | - Kelvin Sim
- OneAnalytix Pte Ltd, Onn Wah Building #04-01, 11 Changi South Lane Singapore, 486154, Singapore
| | - Jeremy C M Teo
- Khalifa University, Abu Dhabi Campus, PO Box, 127788, Abu Dhabi, United Arab Emirates
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10
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Wyroba E, Kwaśniak P, Miller K, Kobyłecki K, Osińska M. Site-directed mutagenesis, in vivo electroporation and mass spectrometry in search for determinants of the subcellular targeting of Rab7b paralogue in the model eukaryote Paramecium octaurelia. Eur J Histochem 2016; 60:2612. [PMID: 27349314 PMCID: PMC4933825 DOI: 10.4081/ejh.2016.2612] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 03/19/2016] [Accepted: 03/21/2016] [Indexed: 11/25/2022] Open
Abstract
Protein products of paralogous genes resulting from whole genome duplication may acquire new functions. The role of post-translational modifications (PTM) in proper targeting of Paramecium Rab7b paralogue (distinct from that of Rab7a directly involved in phagocytosis) was studied using point mutagenesis, proteomic analysis and double immunofluorescence after in vivo electroporation of the mutagenized protein. Here we show that substitution of Thr200 by Ala diminished the incorporation of [P32] by 37% and of [C14-]UDP-glucose by 24% into recombinant Rab7b_200 in comparison to the non-mutagenized control. Double confocal imaging revealed that Rab7b_200 was mistargeted upon electroporation into living cells in contrast to non-mutagenized recombinant Rab7b correctly incorporated in the cytostome area. Using nano LC-MS/MS to compare the peptide map of Rab7b with that after deglycosylation with a mixture of five enzymes of different specificity we identified a peptide ion at m/z=677.63+ representing a glycan group attached to Thr200. Based on its mass and quantitative assays with [P32] and [C14]UDP-glucose, the suggested composition of the adduct attached to Thr200 is (Hex)1(HexNAc)1(Phos)3 or (HexNAc)1 (Deoxyhexose)1 (Phos)1 (HexA)1. These data indicate that PTM of Thr200 located in the hypervariable C-region of Paramecium octaurelia Rab7b is crucial for the proper localization/function of this protein. Moreover, the two Rab7 paralogues differ also in another PTM: substantially more phosphorylated amino acid residues are in Rab7b than in Rab7a.
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Affiliation(s)
- E Wyroba
- Nencki Institute of Experimental Biology of Polish Academy of Sciences.
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11
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Rab32 and Rab38 genes in chordate pigmentation: an evolutionary perspective. BMC Evol Biol 2016; 16:26. [PMID: 26818140 PMCID: PMC4728774 DOI: 10.1186/s12862-016-0596-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 01/18/2016] [Indexed: 11/25/2022] Open
Abstract
Background The regulation of cellular membrane trafficking in all eukaryotes is a very complex mechanism, mostly regulated by the Rab family proteins. Among all membrane-enclosed organelles, melanosomes are the cellular site for synthesis, storage and transport of melanin granules, making them an excellent model for studies on organelle biogenesis and motility. Specific Rab proteins, as Rab32 and Rab38, have been shown to play a key role in melanosome biogenesis. We analysed the Rab32 and Rab38 genes in the teleost zebrafish and in the cephalochordate amphioxus, gaining insight on their evolutionary history following gene and genome duplications. Results We studied the molecular evolution of Rab supergroup III in deuterostomes by phylogenetic reconstruction, intron and synteny conservation. We discovered a novel amino acid stretch, named FALK, shared by three related classes belonging to Rab supergroup III: Rab7L1, Rab32LO and Rab32/Rab38. Among these, we demonstrated that the Rab32LO class, already present in the last common eukaryotic ancestor, was lost in urochordates and vertebrates. Synteny shows that one zebrafish gene, Rab38a, which is expressed in pigmented cells, retained the linkage with tyrosinase, a protein essential for pigmentation. Moreover, the chromosomal linkage of Rab32 or Rab38 with a member of the glutamate receptor metabotropic (Grm) family has been retained in all analysed gnathostomes, suggesting a conserved microsynteny in the vertebrate ancestor. Expression patterns of Rab32 and Rab38 genes in zebrafish, and Rab32/38 in amphioxus, indicate their involvement in development of pigmented cells and notochord. Conclusions Phylogenetic, intron conservation and synteny analyses point towards an evolutionary scenario based on a duplication of a single invertebrate Rab32/38 gene giving rise to vertebrate Rab32 and Rab38. The expression patterns of Rab38 paralogues highlight sub-functionalization event. Finally, the discovery of a chromosomal linkage between the Rab32 or Rab38 gene with a Grm opens new perspectives on possible conserved bystander gene regulation across the vertebrate evolution. Electronic supplementary material The online version of this article (doi:10.1186/s12862-016-0596-1) contains supplementary material, which is available to authorized users.
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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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13
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Nakamura Y, Asano A, Hosaka Y, Takeuchi T, Iwanaga T, Yamano Y. Expression and intracellular localization of TBC1D9, a Rab GTPase-accelerating protein, in mouse testes. Exp Anim 2015; 64:415-24. [PMID: 26119791 PMCID: PMC4637379 DOI: 10.1538/expanim.15-0016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Membrane trafficking in male germ cells contributes to their development via cell morphological changes and acrosome formation. TBC family proteins work as Rab GTPase accelerating proteins (GAPs), which negatively regulate Rab proteins, to mediate membrane trafficking. In this study, we analyzed the expression of a Rab GAP, TBC1D9, in mouse organs and the intracellular localization of the gene products. Tbc1d9 showed abundant expression in adult mice testis. We found that the Tbc1d9 mRNA was expressed in primary and secondary spermatocytes, and that the TBC1D9 protein was expressed in spermatocytes and round spermatids. In 293T cells, TBC1D9-GFP proteins were localized in the endosome and Golgi apparatus. Compartments that were positive for the constitutive active mutants of Rab7 and Rab9 were also positive for TBC1D9 isoform 1. In addition, TBC1D9 proteins were associated with Rab7 and Rab9, respectively. These results indicate that TBC1D9 is expressed mainly in spermatocytes, and suggest that TBC1D9 regulates membrane trafficking pathways related to Rab9- or Rab7-positive vesicles.
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Affiliation(s)
- Yutaka Nakamura
- Laboratory of Veterinary Biochemistry, Faculty of Agriculture, Tottori University, Japan
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14
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Wilson GR, Sim JCH, McLean C, Giannandrea M, Galea CA, Riseley JR, Stephenson SEM, Fitzpatrick E, Haas SA, Pope K, Hogan KJ, Gregg RG, Bromhead CJ, Wargowski DS, Lawrence CH, James PA, Churchyard A, Gao Y, Phelan DG, Gillies G, Salce N, Stanford L, Marsh APL, Mignogna ML, Hayflick SJ, Leventer RJ, Delatycki MB, Mellick GD, Kalscheuer VM, D'Adamo P, Bahlo M, Amor DJ, Lockhart PJ. Mutations in RAB39B cause X-linked intellectual disability and early-onset Parkinson disease with α-synuclein pathology. Am J Hum Genet 2014; 95:729-35. [PMID: 25434005 DOI: 10.1016/j.ajhg.2014.10.015] [Citation(s) in RCA: 181] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 10/30/2014] [Indexed: 11/18/2022] Open
Abstract
Advances in understanding the etiology of Parkinson disease have been driven by the identification of causative mutations in families. Genetic analysis of an Australian family with three males displaying clinical features of early-onset parkinsonism and intellectual disability identified a ∼45 kb deletion resulting in the complete loss of RAB39B. We subsequently identified a missense mutation (c.503C>A [p.Thr168Lys]) in RAB39B in an unrelated Wisconsin kindred affected by a similar clinical phenotype. In silico and in vitro studies demonstrated that the mutation destabilized the protein, consistent with loss of function. In vitro small-hairpin-RNA-mediated knockdown of Rab39b resulted in a reduction in the density of α-synuclein immunoreactive puncta in dendritic processes of cultured neurons. In addition, in multiple cell models, we demonstrated that knockdown of Rab39b was associated with reduced steady-state levels of α-synuclein. Post mortem studies demonstrated that loss of RAB39B resulted in pathologically confirmed Parkinson disease. There was extensive dopaminergic neuron loss in the substantia nigra and widespread classic Lewy body pathology. Additional pathological features included cortical Lewy bodies, brain iron accumulation, tau immunoreactivity, and axonal spheroids. Overall, we have shown that loss-of-function mutations in RAB39B cause intellectual disability and pathologically confirmed early-onset Parkinson disease. The loss of RAB39B results in dysregulation of α-synuclein homeostasis and a spectrum of neuropathological features that implicate RAB39B in the pathogenesis of Parkinson disease and potentially other neurodegenerative disorders.
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Affiliation(s)
- Gabrielle R Wilson
- Bruce Lefroy Centre for Genetic Health Research, Murdoch Childrens Research Institute, Melbourne, VIC 3052, Australia; Department of Paediatrics, University of Melbourne, Melbourne, VIC 3052, Australia
| | - Joe C H Sim
- Bruce Lefroy Centre for Genetic Health Research, Murdoch Childrens Research Institute, Melbourne, VIC 3052, Australia
| | - Catriona McLean
- Anatomical Pathology, The Alfred, Melbourne, VIC 3181, Australia; Australian Brain Bank Network, National Neuroscience Facility, Melbourne, VIC 3053, Australia
| | - Maila Giannandrea
- Dulbecco Telethon Institute at Division of Neuroscience, San Raffaele Scientific Institute, Milan 20132, Italy; Pharmaceutical Research and Early Development, Neuroscience, Ophthalmology, and Rare Diseases, F. Hoffmann-La Roche, Grenzacherstrasse 124, Basel 4070, Switzerland
| | - Charles A Galea
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC 3052, Australia
| | - Jessica R Riseley
- Bruce Lefroy Centre for Genetic Health Research, Murdoch Childrens Research Institute, Melbourne, VIC 3052, Australia
| | - Sarah E M Stephenson
- Bruce Lefroy Centre for Genetic Health Research, Murdoch Childrens Research Institute, Melbourne, VIC 3052, Australia; Department of Paediatrics, University of Melbourne, Melbourne, VIC 3052, Australia
| | - Elizabeth Fitzpatrick
- Bruce Lefroy Centre for Genetic Health Research, Murdoch Childrens Research Institute, Melbourne, VIC 3052, Australia
| | - Stefan A Haas
- Department of Computational Molecular Biology, Max Planck Institute for Molecular Genetics, Ihnestrasse 73, Berlin 14195, Germany
| | - Kate Pope
- Bruce Lefroy Centre for Genetic Health Research, Murdoch Childrens Research Institute, Melbourne, VIC 3052, Australia
| | - Kirk J Hogan
- Department of Anesthesiology, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53792, USA
| | - Ronald G Gregg
- Department of Biochemistry and Molecular Biology, Center for Genetics and Molecular Medicine, University of Louisville, Louisville, KY 40202, USA
| | - Catherine J Bromhead
- Bioinformatics Division, Walter and Eliza Hall Institute, Melbourne, VIC 3052, Australia
| | - David S Wargowski
- Waisman Center, Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Christopher H Lawrence
- Office of the State Forensic Pathologist, Royal Hobart Hospital, Hobart, TAS 7000, Australia
| | - Paul A James
- Genetic Medicine Department, Royal Melbourne Hospital, Melbourne, VIC 3050, Australia
| | - Andrew Churchyard
- Department of Neurology, Monash Children's Hospital, Melbourne, VIC 3168, Australia
| | - Yujing Gao
- Bruce Lefroy Centre for Genetic Health Research, Murdoch Childrens Research Institute, Melbourne, VIC 3052, Australia
| | - Dean G Phelan
- Bruce Lefroy Centre for Genetic Health Research, Murdoch Childrens Research Institute, Melbourne, VIC 3052, Australia; Department of Paediatrics, University of Melbourne, Melbourne, VIC 3052, Australia
| | - Greta Gillies
- Bruce Lefroy Centre for Genetic Health Research, Murdoch Childrens Research Institute, Melbourne, VIC 3052, Australia
| | - Nicholas Salce
- Bruce Lefroy Centre for Genetic Health Research, Murdoch Childrens Research Institute, Melbourne, VIC 3052, Australia
| | - Lynn Stanford
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, OR 97239-3098, USA
| | - Ashley P L Marsh
- Bruce Lefroy Centre for Genetic Health Research, Murdoch Childrens Research Institute, Melbourne, VIC 3052, Australia; Department of Paediatrics, University of Melbourne, Melbourne, VIC 3052, Australia
| | - Maria L Mignogna
- Dulbecco Telethon Institute at Division of Neuroscience, San Raffaele Scientific Institute, Milan 20132, Italy; Pharmaceutical Research and Early Development, Neuroscience, Ophthalmology, and Rare Diseases, F. Hoffmann-La Roche, Grenzacherstrasse 124, Basel 4070, Switzerland
| | - Susan J Hayflick
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, OR 97239-3098, USA
| | - Richard J Leventer
- Bruce Lefroy Centre for Genetic Health Research, Murdoch Childrens Research Institute, Melbourne, VIC 3052, Australia; Department of Paediatrics, University of Melbourne, Melbourne, VIC 3052, Australia; Murdoch Childrens Research Institute, Royal Children's Hospital, Melbourne, VIC 3052, Australia; Department of Neurology, Royal Children's Hospital, Melbourne, VIC 3052, Australia
| | - Martin B Delatycki
- Bruce Lefroy Centre for Genetic Health Research, Murdoch Childrens Research Institute, Melbourne, VIC 3052, Australia; Department of Paediatrics, University of Melbourne, Melbourne, VIC 3052, Australia; Clinical Genetics, Austin Health, Melbourne, VIC 3084, Australia
| | - George D Mellick
- Eskitis Institute for Drug Discovery, Griffith University, Nathan, QLD 4111, Australia
| | - Vera M Kalscheuer
- Department of Human Molecular Genetics, Max Planck Institute for Molecular Genetics, Ihnestrasse 73, Berlin 14195, Germany
| | - Patrizia D'Adamo
- Dulbecco Telethon Institute at Division of Neuroscience, San Raffaele Scientific Institute, Milan 20132, Italy
| | - Melanie Bahlo
- Bioinformatics Division, Walter and Eliza Hall Institute, Melbourne, VIC 3052, Australia; Department of Mathematics and Statistics, University of Melbourne, Melbourne, VIC 3010, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - David J Amor
- Bruce Lefroy Centre for Genetic Health Research, Murdoch Childrens Research Institute, Melbourne, VIC 3052, Australia; Department of Paediatrics, University of Melbourne, Melbourne, VIC 3052, Australia
| | - Paul J Lockhart
- Bruce Lefroy Centre for Genetic Health Research, Murdoch Childrens Research Institute, Melbourne, VIC 3052, Australia; Department of Paediatrics, University of Melbourne, Melbourne, VIC 3052, Australia.
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15
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Wandinger-Ness A, Zerial M. Rab proteins and the compartmentalization of the endosomal system. Cold Spring Harb Perspect Biol 2014; 6:a022616. [PMID: 25341920 PMCID: PMC4413231 DOI: 10.1101/cshperspect.a022616;] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Of the approximately 70 human Rab GTPases, nearly three-quarters are involved in endocytic trafficking. Significant plasticity in endosomal membrane transport pathways is closely coupled to receptor signaling and Rab GTPase-regulated scaffolds. Here we review current literature pertaining to endocytic Rab GTPase localizations, functions, and coordination with regulatory proteins and effectors. The roles of Rab GTPases in (1) compartmentalization of the endocytic pathway into early, recycling, late, and lysosomal routes; (2) coordination of individual transport steps from vesicle budding to fusion; (3) effector interactomes; and (4) integration of GTPase and signaling cascades are discussed.
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Affiliation(s)
- Angela Wandinger-Ness
- Department of Pathology MSC08 4640, University of New Mexico HSC, Albuquerque, New Mexico 87131
| | - Marino Zerial
- Max Planck Institute of Molecular and Cell Biology and Genetics, 01307 Dresden, Germany
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16
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Wandinger-Ness A, Zerial M. Rab proteins and the compartmentalization of the endosomal system. Cold Spring Harb Perspect Biol 2014; 6:a022616. [PMID: 25341920 DOI: 10.1101/cshperspect.a022616] [Citation(s) in RCA: 408] [Impact Index Per Article: 40.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Of the approximately 70 human Rab GTPases, nearly three-quarters are involved in endocytic trafficking. Significant plasticity in endosomal membrane transport pathways is closely coupled to receptor signaling and Rab GTPase-regulated scaffolds. Here we review current literature pertaining to endocytic Rab GTPase localizations, functions, and coordination with regulatory proteins and effectors. The roles of Rab GTPases in (1) compartmentalization of the endocytic pathway into early, recycling, late, and lysosomal routes; (2) coordination of individual transport steps from vesicle budding to fusion; (3) effector interactomes; and (4) integration of GTPase and signaling cascades are discussed.
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Affiliation(s)
- Angela Wandinger-Ness
- Department of Pathology MSC08 4640, University of New Mexico HSC, Albuquerque, New Mexico 87131
| | - Marino Zerial
- Max Planck Institute of Molecular and Cell Biology and Genetics, 01307 Dresden, Germany
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17
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Berson T, von Wangenheim D, Takáč T, Šamajová O, Rosero A, Ovečka M, Komis G, Stelzer EHK, Šamaj J. Trans-Golgi network localized small GTPase RabA1d is involved in cell plate formation and oscillatory root hair growth. BMC PLANT BIOLOGY 2014; 14:252. [PMID: 25260869 PMCID: PMC4180857 DOI: 10.1186/s12870-014-0252-0] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 09/18/2014] [Indexed: 05/19/2023]
Abstract
BACKGROUND Small Rab GTPases are important regulators of vesicular trafficking in plants. AtRabA1d, a member of the RabA1 subfamily of small GTPases, was previously found in the vesicle-rich apical dome of growing root hairs suggesting a role during tip growth; however, its specific intracellular localization and role in plants has not been well described. RESULTS The transient expression of 35S::GFP:RabA1d construct in Allium porrum and Nicotiana benthamiana revealed vesicular structures, which were further corroborated in stable transformed Arabidopsis thaliana plants. GFP-RabA1d colocalized with the trans-Golgi network marker mCherry-VTI12 and with early FM4-64-labeled endosomal compartments. Late endosomes and endoplasmic reticulum labeled with FYVE-DsRed and ER-DsRed, respectively, were devoid of GFP-RabA1d. The accumulation of GFP-RabA1d in the core of brefeldin A (BFA)-induced-compartments and the quantitative upregulation of RabA1d protein levels after BFA treatment confirmed the association of RabA1d with early endosomes/TGN and its role in vesicle trafficking. Light-sheet microscopy revealed involvement of RabA1d in root development. In root cells, GFP-RabA1d followed cell plate expansion consistently with cytokinesis-related vesicular trafficking and membrane recycling. GFP-RabA1d accumulated in disc-like structures of nascent cell plates, which progressively evolved to marginal ring-like structures of the growing cell plates. During root hair growth and development, GFP-RabA1d was enriched at root hair bulges and at the apical dome of vigorously elongating root hairs. Importantly, GFP-RabA1d signal intensity exhibited an oscillatory behavior in-phase with tip growth. Progressively, this tip localization dissapeared in mature root hairs suggesting a link between tip localization of RabA1d and root hair elongation. Our results support a RabA1d role in events that require vigorous membrane trafficking. CONCLUSIONS RabA1d is located in early endosomes/TGN and is involved in vesicle trafficking. RabA1d participates in both cell plate formation and root hair oscillatory tip growth. The specific GFP-RabA1d subcellular localization confirms a correlation between its specific spatio-temporal accumulation and local vesicle trafficking requirements during cell plate and root hair formation.
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Affiliation(s)
- Tobias Berson
- />Institute of Cellular and Molecular Botany, University of Bonn, Kirschallee 1, Bonn, D-53115 Germany
| | - Daniel von Wangenheim
- />Buchmann Institute for Molecular Life Sciences, Goethe-Universität Frankfurt am Main, Max-von-Laue-Str. 15, Frankfurt am Main, 60438 Germany
| | - Tomáš Takáč
- />Centre of the Region Haná for Biotechnological and Agricultural Research, Department of Cell Biology, Faculty of Science, Palacký University, Šlechtitelů 11, Olomouc, 783 71 Czech Republic
| | - Olga Šamajová
- />Centre of the Region Haná for Biotechnological and Agricultural Research, Department of Cell Biology, Faculty of Science, Palacký University, Šlechtitelů 11, Olomouc, 783 71 Czech Republic
| | - Amparo Rosero
- />Centre of the Region Haná for Biotechnological and Agricultural Research, Department of Cell Biology, Faculty of Science, Palacký University, Šlechtitelů 11, Olomouc, 783 71 Czech Republic
| | - Miroslav Ovečka
- />Centre of the Region Haná for Biotechnological and Agricultural Research, Department of Cell Biology, Faculty of Science, Palacký University, Šlechtitelů 11, Olomouc, 783 71 Czech Republic
| | - George Komis
- />Centre of the Region Haná for Biotechnological and Agricultural Research, Department of Cell Biology, Faculty of Science, Palacký University, Šlechtitelů 11, Olomouc, 783 71 Czech Republic
| | - Ernst HK Stelzer
- />Buchmann Institute for Molecular Life Sciences, Goethe-Universität Frankfurt am Main, Max-von-Laue-Str. 15, Frankfurt am Main, 60438 Germany
| | - Jozef Šamaj
- />Centre of the Region Haná for Biotechnological and Agricultural Research, Department of Cell Biology, Faculty of Science, Palacký University, Šlechtitelů 11, Olomouc, 783 71 Czech Republic
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18
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Abstract
Lysosomes were once considered the end point of endocytosis, simply used for macromolecule degradation. They are now recognized to be dynamic organelles, able to fuse with a variety of targets and to be re-formed after fusion events. They are also now known to be the site of nutrient sensing and signaling to the cell nucleus. In addition, lysosomes are secretory organelles, with specialized machinery for regulated secretion of proteins in some cell types. The biogenesis of lysosomes and lysosome-related organelles is discussed, taking into account their dynamic nature and multiple roles.
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