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Ding H, Ding ZG, Liu S, Mao XN, Lu XS. Ras-related protein Rab24 plays a predictive role in hepatocellular carcinoma and enhanced tumor proliferation. World J Gastroenterol 2025; 31:101585. [PMID: 40062325 PMCID: PMC11886508 DOI: 10.3748/wjg.v31.i8.101585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2024] [Revised: 12/04/2024] [Accepted: 01/06/2025] [Indexed: 01/23/2025] Open
Abstract
BACKGROUND Ras-related protein Rab24, which belongs to the small GTPase family, plays a crucial role in regulating intracellular protein trafficking. Dysregulation of Rab24 has been recently identified in hepatocellular carcinoma (HCC). However, its clinical significance and tumor related effects remain to be further clarified. AIM To explore the expression pattern of Rab24 and its role in HCC progression. METHODS The expression profile of Rab24 was tested in HCC tissues together with adjacent tissues from transcriptional, mRNA, and protein levels. The prognostic role of Rab24 in HCC was assessed by univariate and multivariate analyses. Clinical outcomes were evaluated by the Kaplan-Meier analysis and log-rank test. The effect of Rab24 on cell proliferation was tested through cellular experiments and xenograft experiments. RESULTS Rab24 expression was elevated in HCC tissues compared to adjacent liver tissues. High expression of Rab24 was significantly associated with larger tumor size and advanced tumor stage. Moreover, HCC patients with high Rab24 expression showed poorer overall survival, and Rab24 was identified as an independent prognosis factor according to multivariate analysis. By using overexpression and shRNA knockdown strategies in HCC cell lines, we found that Rab24 can promote HCC proliferation. Finally, we validated that silencing Rab24 significantly attenuated xenograft growth in vivo. CONCLUSION Our study demonstrated that high expression of Rab24 was significantly correlated with poorer prognosis of HCC patients, indicating the potential of Rab24 as a novel clinical biomarker and therapeutic target.
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Affiliation(s)
- Han Ding
- Department of Endoscopy Center and Endoscopy Research Institute, Zhongshan Hospital, The Affiliated to Fudan University, Shanghai 200032, China
- Department of General Surgery, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
| | - Zhi-Guo Ding
- Department of General Surgery, The Third People’s Hospital of Yangzhou, Yangzhou 225126, Jiangsu Province, China
| | - Song Liu
- Department of General Surgery, The Fourth Affiliated Hospital of Soochow University, Suzhou 215000, Jiangsu Province, China
| | - Xu-Nan Mao
- Medical College, Yangzhou University, Yangzhou 225009, Jiangsu Province, China
| | - Xing-Sheng Lu
- Department of General Surgery, The Fourth Affiliated Hospital of Soochow University, Suzhou 215000, Jiangsu Province, China
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2
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Gilsbach BK, Ho FY, Riebenbauer B, Zhang X, Guaitoli G, Kortholt A, Gloeckner CJ. Intramolecular feedback regulation of the LRRK2 Roc G domain by a LRRK2 kinase-dependent mechanism. eLife 2024; 12:RP91083. [PMID: 39699947 DOI: 10.7554/elife.91083] [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] [Indexed: 12/20/2024] Open
Abstract
The Parkinson's disease (PD)-linked protein Leucine-Rich Repeat Kinase 2 (LRRK2) consists of seven domains, including a kinase and a Roc G domain. Despite the availability of several high-resolution structures, the dynamic regulation of its unique intramolecular domain stack is nevertheless still not well understood. By in-depth biochemical analysis, assessing the Michaelis-Menten kinetics of the Roc G domain, we have confirmed that LRRK2 has, similar to other Roco protein family members, a KM value of LRRK2 that lies within the range of the physiological GTP concentrations within the cell. Furthermore, the R1441G PD variant located within a mutational hotspot in the Roc domain showed an increased catalytic efficiency. In contrast, the most common PD variant G2019S, located in the kinase domain, showed an increased KM and reduced catalytic efficiency, suggesting a negative feedback mechanism from the kinase domain to the G domain. Autophosphorylation of the G1+2 residue (T1343) in the Roc P-loop motif is critical for this phosphoregulation of both the KM and the kcat values of the Roc-catalyzed GTP hydrolysis, most likely by changing the monomer-dimer equilibrium. The LRRK2 T1343A variant has a similar increased kinase activity in cells compared to G2019S and the double mutant T1343A/G2019S has no further increased activity, suggesting that T1343 is crucial for the negative feedback in the LRRK2 signaling cascade. Together, our data reveal a novel intramolecular feedback regulation of the LRRK2 Roc G domain by a LRRK2 kinase-dependent mechanism. Interestingly, PD mutants differently change the kinetics of the GTPase cycle, which might in part explain the difference in penetrance of these mutations in PD patients.
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Affiliation(s)
- Bernd K Gilsbach
- German Center for Neurodegenerative diseases (DZNE), Tübingen, Germany
| | - Franz Y Ho
- Department of Cell Biochemistry, University of Groningen, Groningen, Netherlands
| | | | - Xiaojuan Zhang
- Department of Cell Biochemistry, University of Groningen, Groningen, Netherlands
| | | | - Arjan Kortholt
- Department of Cell Biochemistry, University of Groningen, Groningen, Netherlands
- YETEM-Innovative Technologies Application and Research Centre, Suleyman Demirel University West Campus, Isparta, Turkey
| | - Christian Johannes Gloeckner
- German Center for Neurodegenerative diseases (DZNE), Tübingen, Germany
- Core Facility for Medical Bioanalytics, Institute for Ophthalmic Research, Center for Ophthalmology, University of Tübingen, Tübingen, Germany
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3
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Waschbüsch D, Khan AR. Phosphorylation of Rab GTPases in the regulation of membrane trafficking. Traffic 2020; 21:712-719. [PMID: 32969543 PMCID: PMC7756361 DOI: 10.1111/tra.12765] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 09/17/2020] [Accepted: 09/17/2020] [Indexed: 12/15/2022]
Abstract
Rab GTPases are master regulators of membrane trafficking in eukaryotic cells. Phosphorylation of Rab GTPases was characterized in the 1990s and there have been intermittent reports of its relevance to Rab functions. Phosphorylation as a regulatory mechanism has gained prominence through the identification of Rabs as physiological substrates of leucine‐rich repeat kinase 2 (LRRK2). LRRK2 is a Ser/Thr kinase that is associated with inherited and sporadic forms of Parkinson disease. In recent years, numerous kinases and their associated signaling pathways have been identified that lead to phosphorylation of Rabs. These emerging studies suggest that serine/threonine and tyrosine phosphorylation of Rabs may be a widespread and under‐appreciated mechanism for controlling their membrane trafficking functions. Here we survey current knowledge of Rab phosphorylation and discuss models for how this post‐translational mechanism exerts control of membrane trafficking.
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Affiliation(s)
- Dieter Waschbüsch
- School of Biochemistry and Immunology, Trinity College, Dublin, Ireland
| | - Amir R Khan
- School of Biochemistry and Immunology, Trinity College, Dublin, Ireland.,Division of Newborn Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
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4
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Kano Y, Gebregiworgis T, Marshall CB, Radulovich N, Poon BPK, St-Germain J, Cook JD, Valencia-Sama I, Grant BMM, Herrera SG, Miao J, Raught B, Irwin MS, Lee JE, Yeh JJ, Zhang ZY, Tsao MS, Ikura M, Ohh M. Tyrosyl phosphorylation of KRAS stalls GTPase cycle via alteration of switch I and II conformation. Nat Commun 2019; 10:224. [PMID: 30644389 PMCID: PMC6333830 DOI: 10.1038/s41467-018-08115-8] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 12/17/2018] [Indexed: 12/27/2022] Open
Abstract
Deregulation of the RAS GTPase cycle due to mutations in the three RAS genes is commonly associated with cancer development. Protein tyrosine phosphatase SHP2 promotes RAF-to-MAPK signaling pathway and is an essential factor in RAS-driven oncogenesis. Despite the emergence of SHP2 inhibitors for the treatment of cancers harbouring mutant KRAS, the mechanism underlying SHP2 activation of KRAS signaling remains unclear. Here we report tyrosyl-phosphorylation of endogenous RAS and demonstrate that KRAS phosphorylation via Src on Tyr32 and Tyr64 alters the conformation of switch I and II regions, which stalls multiple steps of the GTPase cycle and impairs binding to effectors. In contrast, SHP2 dephosphorylates KRAS, a process that is required to maintain dynamic canonical KRAS GTPase cycle. Notably, Src- and SHP2-mediated regulation of KRAS activity extends to oncogenic KRAS and the inhibition of SHP2 disrupts the phosphorylation cycle, shifting the equilibrium of the GTPase cycle towards the stalled ‘dark state’. Deregulation of the RAS GTPase cycle due to mutations in RAS genes is commonly associated with cancer development. Here authors use NMR and mass spectrometry to shows that KRAS phosphorylation via Src alters the conformation of switch I and II regions and thereby impacts the GTPase cycle.
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Affiliation(s)
- Yoshihito Kano
- Department of Laboratory Medicine and Pathobiology, University of Toronto, 661 University Avenue, Toronto, ON, M5G 1M1, Canada.,Department of Biochemistry, University of Toronto, 661 University Avenue, Toronto, ON, M5G 1M1, Canada
| | - Teklab Gebregiworgis
- Princess Margaret Cancer Centre, University Health Network and Department of Medical Biophysics, University of Toronto, 101 College Street, Toronto, ON, M5G 1L7, Canada
| | - Christopher B Marshall
- Princess Margaret Cancer Centre, University Health Network and Department of Medical Biophysics, University of Toronto, 101 College Street, Toronto, ON, M5G 1L7, Canada
| | - Nikolina Radulovich
- Princess Margaret Cancer Centre, University Health Network and Department of Pathology, University of Toronto, Toronto, ON, M5G 1L7, Canada
| | - Betty P K Poon
- Department of Laboratory Medicine and Pathobiology, University of Toronto, 661 University Avenue, Toronto, ON, M5G 1M1, Canada
| | - Jonathan St-Germain
- Princess Margaret Cancer Centre, University Health Network and Department of Medical Biophysics, University of Toronto, 101 College Street, Toronto, ON, M5G 1L7, Canada
| | - Jonathan D Cook
- Department of Laboratory Medicine and Pathobiology, University of Toronto, 661 University Avenue, Toronto, ON, M5G 1M1, Canada
| | - Ivette Valencia-Sama
- Department of Laboratory Medicine and Pathobiology, University of Toronto, 661 University Avenue, Toronto, ON, M5G 1M1, Canada.,Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, 686 Bay Street, Toronto, ON, 5G OA4, Canada
| | - Benjamin M M Grant
- Princess Margaret Cancer Centre, University Health Network and Department of Medical Biophysics, University of Toronto, 101 College Street, Toronto, ON, M5G 1L7, Canada
| | - Silvia Gabriela Herrera
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Jinmin Miao
- Department of Medicinal Chemistry and Molecular Pharmacology, Center for Cancer Research and Institute for Drug Discovery, Purdue University, 720 Clinic Drive, West Lafayette, IN, 47907, USA
| | - Brian Raught
- Princess Margaret Cancer Centre, University Health Network and Department of Medical Biophysics, University of Toronto, 101 College Street, Toronto, ON, M5G 1L7, Canada
| | - Meredith S Irwin
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, 686 Bay Street, Toronto, ON, 5G OA4, Canada
| | - Jeffrey E Lee
- Department of Laboratory Medicine and Pathobiology, University of Toronto, 661 University Avenue, Toronto, ON, M5G 1M1, Canada
| | - Jen Jen Yeh
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, 27599, USA.,Department of Surgery, University of North Carolina, Chapel Hill, NC, 27599, USA.,Department of Pharmacology, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Zhong-Yin Zhang
- Department of Medicinal Chemistry and Molecular Pharmacology, Center for Cancer Research and Institute for Drug Discovery, Purdue University, 720 Clinic Drive, West Lafayette, IN, 47907, USA
| | - Ming-Sound Tsao
- Princess Margaret Cancer Centre, University Health Network and Department of Pathology, University of Toronto, Toronto, ON, M5G 1L7, Canada
| | - Mitsuhiko Ikura
- Princess Margaret Cancer Centre, University Health Network and Department of Medical Biophysics, University of Toronto, 101 College Street, Toronto, ON, M5G 1L7, Canada
| | - Michael Ohh
- Department of Laboratory Medicine and Pathobiology, University of Toronto, 661 University Avenue, Toronto, ON, M5G 1M1, Canada. .,Department of Biochemistry, University of Toronto, 661 University Avenue, Toronto, ON, M5G 1M1, Canada.
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5
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Abstract
Autophagy is an evolutionarily conserved degradation pathway for cells to maintain homeostasis, produce energy, degrade misfolded proteins and damaged organelles, and fight against intracellular pathogens. The process of autophagy entails the isolation of cytoplasmic cargo into double membrane bound autophagosomes that undergo maturation by fusion with endosomes and lysosomes to obtain degradation capacity. RAB proteins regulate intracellular vesicle trafficking events including autophagy. RAB24 is an atypical RAB protein that is required for the clearance of late autophagic vacuoles under basal conditions. RAB24 has also been connected to several diseases including ataxia, cancer and tuberculosis. This review gives a short summary on autophagy and RAB proteins, and an overview on the current knowledge on the roles of RAB24 in autophagy and disease.
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Affiliation(s)
- Päivi Ylä-Anttila
- a Department of Biosciences , University of Helsinki , Helsinki , Finland
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6
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LRRK2 mediated Rab8a phosphorylation promotes lipid storage. Lipids Health Dis 2018; 17:34. [PMID: 29482628 PMCID: PMC5828482 DOI: 10.1186/s12944-018-0684-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 02/19/2018] [Indexed: 01/07/2023] Open
Abstract
Background Several mutations in leucine rich repeat kinase 2 (LRRK2) gene have been associated with pathogenesis of Parkinson’s disease (PD), a neurodegenerative disorder marked by resting tremors, and rigidity, leading to Postural instability. It has been revealed that mutations that lead to an increase of kinase activity of LRRK2 protein are significantly associated with PD pathogenesis. Recent studies have shown that some Rab GTPases, especially Rab8, serve as substrates of LRRK2 and undergo phosphorylation in its switch II domain upon interaction. Current study was performed in order to find out the effects of the phosphorylation of Rab8 and its mutants on lipid metabolism and lipid droplets growth. Methods The phosphorylation status of Rab8a was checked by phos-tag gel. Point mutant construct were generated to investigate the function of Rab8a. 3T3L1 cells were transfected with indicated plasmids and the lipid droplets were stained with Bodipy. Fluorescent microscopy experiments were performed to examine the sizes of lipid droplets. The interactions between Rab8a and Optineurin were determined by immunoprecipitation and western blot. Results Our assays demonstrated that Rab8a was phosphorylated by mutated LRRK2 that exhibits high kinase activity. Phosphorylation of Rab8a on amino acid residue T72 promoted the formation of large lipid droplets. T72D mutant of Rab8a had higher activity to promote the formation of large lipid droplets compared with wild type Rab8a, with increase in average diameter of lipid droplets from 2.10 μm to 2.46 μm. Moreover, phosphorylation of Rab8a weakened the interaction with its effector Optineurin. Conclusions Y1699C mutated LRRK2 was able to phosphorylate Rab8a and phosphorylation of Rab8a on site 72 plays important role in the fusion and enlargement of lipid droplets. Taken together, our study suggests an indirect relationship between enhanced lipid storage capacity and PD pathogenesis.
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7
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Abstract
Autophagy is an evolutionarily conserved degradation pathway for cells to maintain homeostasis, produce energy, degrade misfolded proteins and damaged organelles, and fight against intracellular pathogens. The process of autophagy entails the isolation of cytoplasmic cargo into double membrane bound autophagosomes that undergo maturation by fusion with endosomes and lysosomes to obtain degradation capacity. RAB proteins regulate intracellular vesicle trafficking events including autophagy. RAB24 is an atypical RAB protein that is required for the clearance of late autophagic vacuoles under basal conditions. RAB24 has also been connected to several diseases including ataxia, cancer and tuberculosis. This review gives a short summary on autophagy and RAB proteins, and an overview on the current knowledge on the roles of RAB24 in autophagy and disease.
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Affiliation(s)
- Päivi Ylä-Anttila
- a Department of Biosciences , University of Helsinki , Helsinki , Finland
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8
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Lin X, Zhang J, Chen L, Chen Y, Xu X, Hong W, Wang T. Tyrosine phosphorylation of Rab7 by Src kinase. Cell Signal 2017; 35:84-94. [PMID: 28336235 DOI: 10.1016/j.cellsig.2017.03.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 02/28/2017] [Accepted: 03/14/2017] [Indexed: 12/15/2022]
Abstract
The small molecular weight GTPase Rab7 is a key regulator for late endosomal/lysosomal membrane trafficking, it was known that Rab7 is phosphorylated, but the corresponding kinase and the functional regulation of Rab7 phosphorylation remain unclear. We provide evidence here that Rab7 is a substrate of Src kinase, and is tyrosine-phosphorylated by Src, withY183 residue of Rab7 being the optimal phosphorylation site for Src. Further investigations demonstrated that the tyrosine phosphorylation of Rab7 depends on the guanine nucleotide binding activity of Rab7 and the activity of Src kinase. The tyrosine phosphorylation of Rab7 is physiologically induced by EGF, and impairs the interaction of Rab7 with RILP, consequently inhibiting EGFR degradation and sustaining Akt signaling. These results suggest that the tyrosine phosphorylation of Rab7 may be involved in coordinating membrane trafficking and cell signaling.
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Affiliation(s)
- Xiaosi Lin
- School of Pharmaceutical Sciences, State Key Laboratory of Cellular Stress Biology, Fujian Provincial Key Laboratory of Innovative Drug Target Research, Xiamen University, Fujian 361005, China
| | - Jiaming Zhang
- School of Pharmaceutical Sciences, State Key Laboratory of Cellular Stress Biology, Fujian Provincial Key Laboratory of Innovative Drug Target Research, Xiamen University, Fujian 361005, China
| | - Lingqiu Chen
- School of Pharmaceutical Sciences, State Key Laboratory of Cellular Stress Biology, Fujian Provincial Key Laboratory of Innovative Drug Target Research, Xiamen University, Fujian 361005, China
| | - Yongjun Chen
- School of Pharmaceutical Sciences, State Key Laboratory of Cellular Stress Biology, Fujian Provincial Key Laboratory of Innovative Drug Target Research, Xiamen University, Fujian 361005, China
| | - Xiaohui Xu
- School of Pharmaceutical Sciences, State Key Laboratory of Cellular Stress Biology, Fujian Provincial Key Laboratory of Innovative Drug Target Research, Xiamen University, Fujian 361005, China
| | - Wanjin Hong
- School of Pharmaceutical Sciences, State Key Laboratory of Cellular Stress Biology, Fujian Provincial Key Laboratory of Innovative Drug Target Research, Xiamen University, Fujian 361005, China; Institute of Molecular and Cell Biology, A STAR(Agency of Science, Technology and Research), 61 Biopolis Drive, Singapore 138673, Singapore
| | - Tuanlao Wang
- School of Pharmaceutical Sciences, State Key Laboratory of Cellular Stress Biology, Fujian Provincial Key Laboratory of Innovative Drug Target Research, Xiamen University, Fujian 361005, China.
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9
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Amaya C, Militello RD, Calligaris SD, Colombo MI. Rab24 interacts with the Rab7/Rab interacting lysosomal protein complex to regulate endosomal degradation. Traffic 2016; 17:1181-1196. [PMID: 27550070 DOI: 10.1111/tra.12431] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 08/17/2016] [Accepted: 08/17/2016] [Indexed: 12/11/2022]
Abstract
Endocytosis is a multistep process engaged in extracellular molecules internalization. Several proteins including the Rab GTPases family coordinate the endocytic pathway. The small GTPase Rab7 is present in late endosome (LE) compartments being a marker of endosome maturation. The Rab interacting lysosomal protein (RILP) is a downstream effector of Rab7 that recruits the functional dynein/dynactin motor complex to late compartments. In the present study, we have found Rab24 as a component of the endosome-lysosome degradative pathway. Rab24 is an atypical protein of the Rab GTPase family, which has been attributed a function in vesicle trafficking and autophagosome maturation. Using a model of transiently expressed proteins in K562 cells, we found that Rab24 co-localizes in vesicular structures labeled with Rab7 and LAMP1. Moreover, using a dominant negative mutant of Rab24 or a siRNA-Rab24 we showed that the distribution of Rab7 in vesicles depends on a functional Rab24 to allow DQ-BSA protein degradation. Additionally, by immunoprecipitation and pull down assays, we have demonstrated that Rab24 interacts with Rab7 and RILP. Interestingly, overexpression of the Vps41 subunit from the homotypic fusion and protein-sorting (HOPS) complex hampered the co-localization of Rab24 with RILP or with the lysosomal GTPase Arl8b, suggesting that Vps41 would affect the Rab24/RILP association. In summary, our data strongly support the hypothesis that Rab24 forms a complex with Rab7 and RILP on the membranes of late compartments. Our work provides new insights into the molecular function of Rab24 in the last steps of the endosomal degradative pathway.
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Affiliation(s)
- Celina Amaya
- Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología (IHEM)-CONICET, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Rodrigo D Militello
- Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología (IHEM)-CONICET, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Sebastián D Calligaris
- Centro de Medicina Regenerativa, Facultad de Medicina, Universidad del Desarrollo Clínica Alemana, Santiago, Chile
| | - María I Colombo
- Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología (IHEM)-CONICET, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina.
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10
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Kano Y, Cook JD, Lee JE, Ohh M. New structural and functional insight into the regulation of Ras. Semin Cell Dev Biol 2016; 58:70-8. [DOI: 10.1016/j.semcdb.2016.06.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 06/06/2016] [Accepted: 06/07/2016] [Indexed: 10/21/2022]
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11
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Ylä-Anttila P, Mikkonen E, Happonen KE, Holland P, Ueno T, Simonsen A, Eskelinen EL. RAB24 facilitates clearance of autophagic compartments during basal conditions. Autophagy 2016; 11:1833-48. [PMID: 26325487 DOI: 10.1080/15548627.2015.1086522] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
RAB24 belongs to a family of small GTPases and has been implicated to function in autophagy. Here we confirm the intracellular localization of RAB24 to autophagic vacuoles with immuno electron microscopy and cell fractionation, and show that prenylation and guanine nucleotide binding are necessary for the targeting of RAB24 to autophagic compartments. Further, we show that RAB24 plays a role in the maturation and/or clearance of autophagic compartments under nutrient-rich conditions, but not during short amino acid starvation. Quantitative electron microscopy shows an increase in the numbers of late autophagic compartments in cells silenced for RAB24, and mRFP-GFP-LC3 probe and autophagy flux experiments indicate that this is due to a hindrance in their clearance. Formation of autophagosomes is shown to be unaffected by RAB24-silencing with siRNA. A defect in aggregate clearance in the absence of RAB24 is also shown in cells forming polyglutamine aggregates. This study places RAB24 function in the termination of the autophagic process under nutrient-rich conditions.
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Affiliation(s)
- Päivi Ylä-Anttila
- a Department of Biosciences, Division of Biochemistry and Biotechnology; University of Helsinki ; Helsinki , Finland
| | - Elisa Mikkonen
- a Department of Biosciences, Division of Biochemistry and Biotechnology; University of Helsinki ; Helsinki , Finland
| | - Kaisa E Happonen
- a Department of Biosciences, Division of Biochemistry and Biotechnology; University of Helsinki ; Helsinki , Finland
| | - Petter Holland
- b Department of Biochemistry, Institute of Basic Medical Sciences; University of Oslo ; Oslo , Norway
| | - Takashi Ueno
- c Laboratory of Proteomics and Biomolecular Science; Research Support Center; Juntendo University Graduate School of Medicine ; Tokyo , Japan
| | - Anne Simonsen
- b Department of Biochemistry, Institute of Basic Medical Sciences; University of Oslo ; Oslo , Norway
| | - Eeva-Liisa Eskelinen
- a Department of Biosciences, Division of Biochemistry and Biotechnology; University of Helsinki ; Helsinki , Finland
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12
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Innate immunity kinase TAK1 phosphorylates Rab1 on a hotspot for posttranslational modifications by host and pathogen. Proc Natl Acad Sci U S A 2016; 113:E4776-83. [PMID: 27482120 DOI: 10.1073/pnas.1608355113] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
TGF-β activated kinase 1 (TAK1) is a critical signaling hub responsible for translating antigen binding signals to immune receptors for the activation of the AP-1 and NF-κB master transcriptional programs. Despite its importance, known substrates of TAK1 are limited to kinases of the MAPK and IKK families and include no direct effectors of biochemical processes. Here, we identify over 200 substrates of TAK1 using a chemical genetic kinase strategy. We validate phosphorylation of the dynamic switch II region of GTPase Rab1, a mediator of endoplasmic reticulum to Golgi vesicular transport, at T75 to be regulated by TAK1 in vivo. TAK1 preferentially phosphorylates the inactive (GDP-bound) state of Rab1. Phosphorylation of Rab1 disrupts interaction with GDP dissociation inhibitor 1 (GDI1), but not guanine exchange factor (GEF) or GTPase-activating protein (GAP) enzymes, and is exclusive to membrane-localized Rab1, suggesting phosphorylation may stimulate Rab1 membrane association. Furthermore, we found phosphorylation of Rab1 at T75 to be essential for Rab1 function. Previous studies established that the pathogen Legionella pneumophila is capable of hijacking Rab1 function through posttranslational modifications of the switch II region. Here, we present evidence that Rab1 is regulated by the host in a similar fashion, and that the innate immunity kinase TAK1 and Legionella effectors compete to regulate Rab1 by switch II modifications during infection.
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13
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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: 0.2] [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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14
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Abstract
Many viruses exploit specific arms of the endomembrane system. The unique composition of each arm prompts the development of remarkably specific interactions between viruses and sub-organelles. This review focuses on the viral–host interactions occurring on the endocytic recycling compartment (ERC), and mediated by its regulatory Ras-related in brain (Rab) GTPase Rab11. This protein regulates trafficking from the ERC and the trans-Golgi network to the plasma membrane. Such transport comprises intricate networks of proteins/lipids operating sequentially from the membrane of origin up to the cell surface. Rab11 is also emerging as a critical factor in an increasing number of infections by major animal viruses, including pathogens that provoke human disease. Understanding the interplay between the ERC and viruses is a milestone in human health. Rab11 has been associated with several steps of the viral lifecycles by unclear processes that use sophisticated diversified host machinery. For this reason, we first explore the state-of-the-art on processes regulating membrane composition and trafficking. Subsequently, this review outlines viral interactions with the ERC, highlighting current knowledge on viral-host binding partners. Finally, using examples from the few mechanistic studies available we emphasize how ERC functions are adjusted during infection to remodel cytoskeleton dynamics, innate immunity and membrane composition.
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Affiliation(s)
- Sílvia Vale-Costa
- Cell Biology of Viral Infection Lab, Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 6, 2780-156 Oeiras, Portugal.
| | - Maria João Amorim
- Cell Biology of Viral Infection Lab, Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 6, 2780-156 Oeiras, Portugal.
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Amaya C, Fader CM, Colombo MI. Autophagy and proteins involved in vesicular trafficking. FEBS Lett 2015; 589:3343-53. [PMID: 26450776 DOI: 10.1016/j.febslet.2015.09.021] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 09/19/2015] [Accepted: 09/22/2015] [Indexed: 12/16/2022]
Abstract
Autophagy is an intracellular degradation system that, as a basic mechanism it delivers cytoplasmic components to the lysosomes in order to maintain adequate energy levels and cellular homeostasis. This complex cellular process is activated by low cellular nutrient levels and other stress situations such as low ATP levels, the accumulation of damaged proteins or organelles, or pathogen invasion. Autophagy as a multistep process involves vesicular transport events leading to tethering and fusion of autophagic vesicles with several intracellular compartments. This review summarizes our current understanding of the autophagic pathway with emphasis in the trafficking machinery (i.e. Rabs GTPases and SNAP receptors (SNAREs)) involved in specific steps of the pathway.
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Affiliation(s)
- Celina Amaya
- Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología (IHEM)-CONICET, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Casilla de Correo 56, Centro Universitario, Parque General San Martín, 5500 Mendoza, Argentina
| | - Claudio Marcelo Fader
- Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología (IHEM)-CONICET, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Casilla de Correo 56, Centro Universitario, Parque General San Martín, 5500 Mendoza, Argentina
| | - María Isabel Colombo
- Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología (IHEM)-CONICET, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Casilla de Correo 56, Centro Universitario, Parque General San Martín, 5500 Mendoza, Argentina.
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Yun HJ, Kim H, Ga I, Oh H, Ho DH, Kim J, Seo H, Son I, Seol W. An early endosome regulator, Rab5b, is an LRRK2 kinase substrate. J Biochem 2015; 157:485-95. [PMID: 25605758 DOI: 10.1093/jb/mvv005] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 12/18/2014] [Indexed: 11/13/2022] Open
Abstract
Leucine-rich repeat kinase 2 (LRRK2) has been identified as a causative gene for Parkinson's disease (PD). LRRK2 contains a kinase and a GTPase domain, both of which provide critical intracellular signal-transduction functions. We showed previously that Rab5b, a small GTPase protein that regulates the motility and fusion of early endosomes, interacts with LRRK2 and co-regulates synaptic vesicle endocytosis. Using recombinant proteins, we show here that LRRK2 phosphorylates Rab5b at its Thr6 residue in in vitro kinase assays with mass spectrophotometry analysis. Phosphorylation of Rab5b by LRRK2 on the threonine residue was confirmed by western analysis using cells stably expressing LRRK2 G2019S. The phosphomimetic T6D mutant exhibited stronger GTPase activity than that of the wild-type Rab5b. In addition, phosphorylation of Rab5b by LRRK2 also exhibited GTPase activity stronger than that of the unphosphorylated Rab5b protein. Two assays testing Rab5's activity, neurite outgrowth analysis and epidermal growth factor receptor degradation assays, showed that Rab5b T6D exhibited phenotypes that were expected to be observed in the inactive Rab5b, including longer neurite length and less degradation of EGFR. These results suggest that LRRK2 kinase activity functions as a Rab5b GTPase activating protein and thus, negatively regulates Rab5b signalling.
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Affiliation(s)
- Hye Jin Yun
- Institute for Brain Science and Technology, Inje University, Gaegumdong, Busanjingu, Busan, South Korea; InAm Neuroscience Research Center, Sanbon Medical Center, College of Medicine, Wonkwang University, Sanbondong, Gunposhi, Gyeonggido, South Korea; Department of Molecular and Life Sciences, Hanyang University, Ansanshi, Gyeonggido, South Korea; and Department of Neurology, Sanbon Medical Center, College of Medicine, Wonkwang University, Sanbondong, Gunposhi, Gyeonggido, South Korea
| | - Hyejung Kim
- Institute for Brain Science and Technology, Inje University, Gaegumdong, Busanjingu, Busan, South Korea; InAm Neuroscience Research Center, Sanbon Medical Center, College of Medicine, Wonkwang University, Sanbondong, Gunposhi, Gyeonggido, South Korea; Department of Molecular and Life Sciences, Hanyang University, Ansanshi, Gyeonggido, South Korea; and Department of Neurology, Sanbon Medical Center, College of Medicine, Wonkwang University, Sanbondong, Gunposhi, Gyeonggido, South Korea
| | - Inhwa Ga
- Institute for Brain Science and Technology, Inje University, Gaegumdong, Busanjingu, Busan, South Korea; InAm Neuroscience Research Center, Sanbon Medical Center, College of Medicine, Wonkwang University, Sanbondong, Gunposhi, Gyeonggido, South Korea; Department of Molecular and Life Sciences, Hanyang University, Ansanshi, Gyeonggido, South Korea; and Department of Neurology, Sanbon Medical Center, College of Medicine, Wonkwang University, Sanbondong, Gunposhi, Gyeonggido, South Korea
| | - Hakjin Oh
- Institute for Brain Science and Technology, Inje University, Gaegumdong, Busanjingu, Busan, South Korea; InAm Neuroscience Research Center, Sanbon Medical Center, College of Medicine, Wonkwang University, Sanbondong, Gunposhi, Gyeonggido, South Korea; Department of Molecular and Life Sciences, Hanyang University, Ansanshi, Gyeonggido, South Korea; and Department of Neurology, Sanbon Medical Center, College of Medicine, Wonkwang University, Sanbondong, Gunposhi, Gyeonggido, South Korea
| | - Dong Hwan Ho
- Institute for Brain Science and Technology, Inje University, Gaegumdong, Busanjingu, Busan, South Korea; InAm Neuroscience Research Center, Sanbon Medical Center, College of Medicine, Wonkwang University, Sanbondong, Gunposhi, Gyeonggido, South Korea; Department of Molecular and Life Sciences, Hanyang University, Ansanshi, Gyeonggido, South Korea; and Department of Neurology, Sanbon Medical Center, College of Medicine, Wonkwang University, Sanbondong, Gunposhi, Gyeonggido, South Korea Institute for Brain Science and Technology, Inje University, Gaegumdong, Busanjingu, Busan, South Korea; InAm Neuroscience Research Center, Sanbon Medical Center, College of Medicine, Wonkwang University, Sanbondong, Gunposhi, Gyeonggido, South Korea; Department of Molecular and Life Sciences, Hanyang University, Ansanshi, Gyeonggido, South Korea; and Department of Neurology, Sanbon Medical Center, College of Medicine, Wonkwang University, Sanbondong, Gunposhi, Gyeonggido, South Korea
| | - Jiyoung Kim
- Institute for Brain Science and Technology, Inje University, Gaegumdong, Busanjingu, Busan, South Korea; InAm Neuroscience Research Center, Sanbon Medical Center, College of Medicine, Wonkwang University, Sanbondong, Gunposhi, Gyeonggido, South Korea; Department of Molecular and Life Sciences, Hanyang University, Ansanshi, Gyeonggido, South Korea; and Department of Neurology, Sanbon Medical Center, College of Medicine, Wonkwang University, Sanbondong, Gunposhi, Gyeonggido, South Korea
| | - Hyemyung Seo
- Institute for Brain Science and Technology, Inje University, Gaegumdong, Busanjingu, Busan, South Korea; InAm Neuroscience Research Center, Sanbon Medical Center, College of Medicine, Wonkwang University, Sanbondong, Gunposhi, Gyeonggido, South Korea; Department of Molecular and Life Sciences, Hanyang University, Ansanshi, Gyeonggido, South Korea; and Department of Neurology, Sanbon Medical Center, College of Medicine, Wonkwang University, Sanbondong, Gunposhi, Gyeonggido, South Korea
| | - Ilhong Son
- Institute for Brain Science and Technology, Inje University, Gaegumdong, Busanjingu, Busan, South Korea; InAm Neuroscience Research Center, Sanbon Medical Center, College of Medicine, Wonkwang University, Sanbondong, Gunposhi, Gyeonggido, South Korea; Department of Molecular and Life Sciences, Hanyang University, Ansanshi, Gyeonggido, South Korea; and Department of Neurology, Sanbon Medical Center, College of Medicine, Wonkwang University, Sanbondong, Gunposhi, Gyeonggido, South Korea Institute for Brain Science and Technology, Inje University, Gaegumdong, Busanjingu, Busan, South Korea; InAm Neuroscience Research Center, Sanbon Medical Center, College of Medicine, Wonkwang University, Sanbondong, Gunposhi, Gyeonggido, South Korea; Department of Molecular and Life Sciences, Hanyang University, Ansanshi, Gyeonggido, South Korea; and Department of Neurology, Sanbon Medical Center, College of Medicine, Wonkwang University, Sanbondong, Gunposhi, Gyeonggido, South Korea
| | - Wongi Seol
- Institute for Brain Science and Technology, Inje University, Gaegumdong, Busanjingu, Busan, South Korea; InAm Neuroscience Research Center, Sanbon Medical Center, College of Medicine, Wonkwang University, Sanbondong, Gunposhi, Gyeonggido, South Korea; Department of Molecular and Life Sciences, Hanyang University, Ansanshi, Gyeonggido, South Korea; and Department of Neurology, Sanbon Medical Center, College of Medicine, Wonkwang University, Sanbondong, Gunposhi, Gyeonggido, South Korea Institute for Brain Science and Technology, Inje University, Gaegumdong, Busanjingu, Busan, South Korea; InAm Neuroscience Research Center, Sanbon Medical Center, College of Medicine, Wonkwang University, Sanbondong, Gunposhi, Gyeonggido, South Korea; Department of Molecular and Life Sciences, Hanyang University, Ansanshi, Gyeonggido, South Korea; and Department of Neurology, Sanbon Medical Center, College of Medicine, Wonkwang University, Sanbondong, Gunposhi, Gyeonggido, South Korea
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Src promotes GTPase activity of Ras via tyrosine 32 phosphorylation. Proc Natl Acad Sci U S A 2014; 111:E3785-94. [PMID: 25157176 DOI: 10.1073/pnas.1406559111] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mutations in Ras GTPase and various other components of the Ras signaling pathways are among the most common genetic alterations in human cancers and also have been identified in several familial developmental syndromes. Over the past few decades it has become clear that the activity or the oncogenic potential of Ras is dependent on the nonreceptor tyrosine kinase Src to promote the Ras/Raf/MAPK pathway essential for proliferation, differentiation, and survival of eukaryotic cells. However, no direct relationship between Ras and Src has been established. We show here that Src binds to and phosphorylates GTP-, but not GDP-, loaded Ras on a conserved Y32 residue within the switch I region in vitro and that in vivo, Ras-Y32 phosphorylation markedly reduces the binding to effector Raf and concomitantly increases binding to GTPase-activating proteins and the rate of GTP hydrolysis. These results suggest that, in the context of predetermined crystallographic structures, Ras-Y32 serves as an Src-dependent keystone regulatory residue that modulates Ras GTPase activity and ensures unidirectionality to the Ras GTPase cycle.
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Lall P, Horgan CP, Oda S, Franklin E, Sultana A, Hanscom SR, McCaffrey MW, Khan AR. Structural and functional analysis of FIP2 binding to the endosome-localised Rab25 GTPase. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2013; 1834:2679-90. [PMID: 24056041 DOI: 10.1016/j.bbapap.2013.09.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Revised: 09/08/2013] [Accepted: 09/12/2013] [Indexed: 11/30/2022]
Abstract
Rab small GTPases are the master regulators of intracellular trafficking in eukaryotes. They mediate spatial and temporal recruitment of effector proteins to distinct cellular compartments through GTP-induced changes in their conformation. Despite numerous structural studies, the molecular basis for Rab/effector specificity and subsequent biological activity remains poorly understood. Rab25, also known as Rab11c, which is epithelial-specific, has been heavily implicated in ovarian cancer development and independently appears to act as a tumour suppressor in the context of a distinct subset of carcinomas. Here, we show that Rab25 associates with FIP2 and can recruit this effector protein to endosomal membranes. We report the crystal structure of Rab25 in complex with the C-terminal region of FIP2, which consists of a central dimeric FIP2 coiled-coil that mediates a heterotetrameric Rab25-(FIP2)2-Rab25 complex. Thermodynamic analyses show that, despite a relatively conserved interface, FIP2 binds to Rab25 with an approximate 3-fold weaker affinity than to Rab11a. Reduced affinity is mainly associated with lower enthalpic gains for Rab25:FIP2 complex formation, and can be attributed to subtle differences in the conformations of switch 1 and switch 2. These cellular, structural and thermodynamic studies provide insight into the Rab11/Rab25 subfamily of small GTPases that regulate endosomal trafficking pathways in eukaryotes.
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Affiliation(s)
- Patrick Lall
- School of Biochemistry and Immunology, Trinity College, Dublin 2, Ireland
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Lewandowska A, Macfarlane J, Shaw JM. Mitochondrial association, protein phosphorylation, and degradation regulate the availability of the active Rab GTPase Ypt11 for mitochondrial inheritance. Mol Biol Cell 2013; 24:1185-95. [PMID: 23427260 PMCID: PMC3623639 DOI: 10.1091/mbc.e12-12-0848] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
There are conflicting models regarding the role of the Ypt11 GTPase in mitochondrial inheritance during yeast budding. This study demonstrates that Ypt11 function requires mitochondrial membrane targeting and GTPase domain–dependent effector interactions. In addition, the abundance of active Ypt11 forms is controlled by phosphorylation and degradation. The Rab GTPase Ypt11 is a Myo2-binding protein implicated in mother-to-bud transport of the cortical endoplasmic reticulum (ER), late Golgi, and mitochondria during yeast division. However, its reported subcellular localization does not reflect all of these functions. Here we show that Ypt11 is normally a low-abundance protein whose ER localization is only detected when the protein is highly overexpressed. Although it has been suggested that ER-localized Ypt11 and ER–mitochondrial contact sites might mediate passive transport of mitochondria into the bud, we found that mitochondrial, but not ER, association is essential for Ypt11 function in mitochondrial inheritance. Our studies also reveal that Ypt11 function is regulated at multiple levels. In addition to membrane targeting and GTPase domain–dependent effector interactions, the abundance of active Ypt11 forms is controlled by phosphorylation status and degradation. We present a model that synthesizes these new features of Ypt11 function and regulation in mitochondrial inheritance.
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Affiliation(s)
- Agnieszka Lewandowska
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
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Cancino J, Luini A. Signaling Circuits on the Golgi Complex. Traffic 2012; 14:121-34. [DOI: 10.1111/tra.12022] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 10/12/2012] [Accepted: 10/12/2012] [Indexed: 01/21/2023]
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Gloeckner CJ, Boldt K, von Zweydorf F, Helm S, Wiesent L, Sarioglu H, Ueffing M. Phosphopeptide analysis reveals two discrete clusters of phosphorylation in the N-terminus and the Roc domain of the Parkinson-disease associated protein kinase LRRK2. J Proteome Res 2010; 9:1738-45. [PMID: 20108944 DOI: 10.1021/pr9008578] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Mutations in leucine-rich repeat kinase 2 (LRRK2) that increase its kinase activity associate with familial forms of Parkinson disease (PD). As phosphorylation determines the functional state of most protein kinases, we systematically mapped LRRK2 phosphorylation sites by mass spectrometry. Our analysis revealed a high degree of constitutive phosphorylation in a narrow serine-rich region preceding the LRR-domain. Allowing de novo autophosphorylation of purified LRRK2 in an in vitro autokinase assay prior to mass spectrometric analysis, we discovered multiple sites of autophosphorylation. Solely serine and threonine residues were found phosphorylated suggesting LRRK2 as a true serine threonine kinase. Autophosphorylation mainly targets the ROC GTPase domain and its clustering around the GTP binding pocket of ROC suggests cross-regulatory activity between kinase and Roc domain. In conclusion, the phosphoprotein LRRK2 functions as an autocatalytically active serine threonine kinase. Clustering of phosphosites within two discrete domains suggest that phosphorylation may regulate its biological functions in a yet unknown fashion.
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Affiliation(s)
- Christian Johannes Gloeckner
- Helmholtz Zentrum München-German Research Center for Environmental Health, Department of Protein Science, Neuherberg, Germany
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Rab GTPases as coordinators of vesicle traffic. Nat Rev Mol Cell Biol 2009. [DOI: 10.1038/nrm2728 and 5410=5410-- pmza] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Stenmark H. Rab GTPases as coordinators of vesicle traffic. Nat Rev Mol Cell Biol 2009. [DOI: 10.1038/nrm2728 and 6285=8708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Stenmark H. Rab GTPases as coordinators of vesicle traffic. Nat Rev Mol Cell Biol 2009. [DOI: 10.1038/nrm2728 order by 1-- gjxv] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Rab GTPases as coordinators of vesicle traffic. Nat Rev Mol Cell Biol 2009. [DOI: 10.1038/nrm2728 order by 1#] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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