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Hu J, Fu S, Zhan Z, Zhang J. Advancements in dual-target inhibitors of PI3K for tumor therapy: Clinical progress, development strategies, prospects. Eur J Med Chem 2024; 265:116109. [PMID: 38183777 DOI: 10.1016/j.ejmech.2023.116109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 12/24/2023] [Accepted: 12/28/2023] [Indexed: 01/08/2024]
Abstract
Phosphoinositide 3-kinases (PI3Ks) modify lipids by the phosphorylation of inositol phospholipids at the 3'-OH position, thereby participating in signal transduction and exerting effects on various physiological processes such as cell growth, metabolism, and organism development. PI3K activation also drives cancer cell growth, survival, and metabolism, with genetic dysregulation of this pathway observed in diverse human cancers. Therefore, this target is considered a promising potential therapeutic target for various types of cancer. Currently, several selective PI3K inhibitors and one dual-target PI3K inhibitor have been approved and launched on the market. However, the majority of these inhibitors have faced revocation or voluntary withdrawal of indications due to concerns regarding their adverse effects. This article provides a comprehensive review of the structure and biological functions, and clinical status of PI3K inhibitors, with a specific emphasis on the development strategies and structure-activity relationships of dual-target PI3K inhibitors. The findings offer valuable insights and future directions for the development of highly promising dual-target drugs targeting PI3K.
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Affiliation(s)
- Jiarui Hu
- Department of Neurology, Joint Research Institution of Altitude Health and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China; State Key Laboratory of Biotherapy and Cancer Center, Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, China
| | - Siyu Fu
- Department of Neurology, Joint Research Institution of Altitude Health and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China; State Key Laboratory of Biotherapy and Cancer Center, Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, China
| | - Zixuan Zhan
- Department of Neurology, Joint Research Institution of Altitude Health and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Jifa Zhang
- Department of Neurology, Joint Research Institution of Altitude Health and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China; State Key Laboratory of Biotherapy and Cancer Center, Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, China.
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2
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Noda NN. Structural view on autophagosome formation. FEBS Lett 2024; 598:84-106. [PMID: 37758522 DOI: 10.1002/1873-3468.14742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 09/02/2023] [Accepted: 09/04/2023] [Indexed: 09/29/2023]
Abstract
Autophagy is a conserved intracellular degradation system in eukaryotes, involving the sequestration of degradation targets into autophagosomes, which are subsequently delivered to lysosomes (or vacuoles in yeasts and plants) for degradation. In budding yeast, starvation-induced autophagosome formation relies on approximately 20 core Atg proteins, grouped into six functional categories: the Atg1/ULK complex, the phosphatidylinositol-3 kinase complex, the Atg9 transmembrane protein, the Atg2-Atg18/WIPI complex, the Atg8 lipidation system, and the Atg12-Atg5 conjugation system. Additionally, selective autophagy requires cargo receptors and other factors, including a fission factor, for specific sequestration. This review covers the 30-year history of structural studies on core Atg proteins and factors involved in selective autophagy, examining X-ray crystallography, NMR, and cryo-EM techniques. The molecular mechanisms of autophagy are explored based on protein structures, and future directions in the structural biology of autophagy are discussed, considering the advancements in the era of AlphaFold.
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Affiliation(s)
- Nobuo N Noda
- Institute for Genetic Medicine, Hokkaido University, Sapporo, Japan
- Institute of Microbial Chemistry (BIKAKEN), Tokyo, Japan
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3
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Du J, Dong Y, Zuo W, Deng Y, Zhu H, Yu Q, Li M. Mec1-Rad53 Signaling Regulates DNA Damage-Induced Autophagy and Pathogenicity in Candida albicans. J Fungi (Basel) 2023; 9:1181. [PMID: 38132782 PMCID: PMC10744610 DOI: 10.3390/jof9121181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 12/03/2023] [Accepted: 12/07/2023] [Indexed: 12/23/2023] Open
Abstract
DNA damage activates the DNA damage response and autophagy in C. albicans; however, the relationship between the DNA damage response and DNA damage-induced autophagy in C. albicans remains unclear. Mec1-Rad53 signaling is a critical pathway in the DNA damage response, but its role in DNA damage-induced autophagy and pathogenicity in C. albicans remains to be further explored. In this study, we compared the function of autophagy-related (Atg) proteins in DNA damage-induced autophagy and traditional macroautophagy and explored the role of Mec1-Rad53 signaling in regulating DNA damage-induced autophagy and pathogenicity. We found that core Atg proteins are required for these two types of autophagy, while the function of Atg17 is slightly different. Our results showed that Mec1-Rad53 signaling specifically regulates DNA damage-induced autophagy but has no effect on macroautophagy. The recruitment of Atg1 and Atg13 to phagophore assembly sites (PAS) was significantly inhibited in the mec1Δ/Δ and rad53Δ/Δ strains. The formation of autophagic bodies was obviously affected in the mec1Δ/Δ and rad53Δ/Δ strains. We found that DNA damage does not induce mitophagy and ER autophagy. We also identified two regulators of DNA damage-induced autophagy, Psp2 and Dcp2, which regulate DNA damage-induced autophagy by affecting the protein levels of Atg1, Atg13, Mec1, and Rad53. The deletion of Mec1 or Rad53 significantly reduces the ability of C. albicans to systematically infect mice and colonize the kidneys, and it makes C. albicans more susceptible to being killed by macrophages.
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Affiliation(s)
| | | | | | | | | | | | - Mingchun Li
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, 94 Weijin Road, Nankai District, Tianjin 300071, China; (J.D.); (Y.D.); (W.Z.); (Y.D.); (H.Z.); (Q.Y.)
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4
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Lee Y, Kim B, Jang HS, Huh WK. Atg1-dependent phosphorylation of Vps34 is required for dynamic regulation of the phagophore assembly site and autophagy in Saccharomyces cerevisiae. Autophagy 2023; 19:2428-2442. [PMID: 36803233 PMCID: PMC10392759 DOI: 10.1080/15548627.2023.2182478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 02/13/2023] [Accepted: 02/15/2023] [Indexed: 02/22/2023] Open
Abstract
Macroautophagy/autophagy is a key catabolic pathway in which double-membrane autophagosomes sequester various substrates destined for degradation, enabling cells to maintain homeostasis and survive under stressful conditions. Several autophagy-related (Atg) proteins are recruited to the phagophore assembly site (PAS) and cooperatively function to generate autophagosomes. Vps34 is a class III phosphatidylinositol 3-kinase, and Atg14-containing Vps34 complex I plays essential roles in autophagosome formation. However, the regulatory mechanisms of yeast Vps34 complex I are still poorly understood. Here, we demonstrate that Atg1-dependent phosphorylation of Vps34 is required for robust autophagy activity in Saccharomyces cerevisiae. Following nitrogen starvation, Vps34 in complex I is selectively phosphorylated on multiple serine/threonine residues in its helical domain. This phosphorylation is important for full autophagy activation and cell survival. The absence of Atg1 or its kinase activity leads to complete loss of Vps34 phosphorylation in vivo, and Atg1 directly phosphorylates Vps34 in vitro, regardless of its complex association type. We also demonstrate that the localization of Vps34 complex I to the PAS provides a molecular basis for the complex I-specific phosphorylation of Vps34. This phosphorylation is required for the normal dynamics of Atg18 and Atg8 at the PAS. Together, our results reveal a novel regulatory mechanism of yeast Vps34 complex I and provide new insights into the Atg1-dependent dynamic regulation of the PAS.Abbreviations: ATG: autophagy-related; BARA: the repeated, autophagy-specific Co-IP: co-immunoprecipitation; GFP: green fluorescent protein; IP-MS: immunoprecipitation followed by tandem mass spectrometry; NTD: the N-terminal domain; PAS: phagophore assembly site; PtdIns3P: phosphatidylinositol-3-phosphate; PtdIns3K: phosphatidylinositol 3-kinase; SUR: structurally uncharacterized region; Vps34[KD]: Vps34D731N.
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Affiliation(s)
- Yongook Lee
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea
| | - Bongkeun Kim
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea
| | - Hae-Soo Jang
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea
| | - Won-Ki Huh
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea
- Institute of Microbiology, Seoul National University, Seoul, Republic of Korea
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5
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Vps21 Directs the PI3K-PI(3)P-Atg21-Atg16 Module to Phagophores via Vps8 for Autophagy. Int J Mol Sci 2022; 23:ijms23179550. [PMID: 36076954 PMCID: PMC9455592 DOI: 10.3390/ijms23179550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Revised: 08/20/2022] [Accepted: 08/21/2022] [Indexed: 11/28/2022] Open
Abstract
Phosphatidylinositol 3-phosphate (PI(3)P) serves important functions in endocytosis, phagocytosis, and autophagy. PI(3)P is generated by Vps34 of the class III phosphatidylinositol 3-kinase (PI3K) complex. The Vps34-PI3K complex can be divided into Vps34-PI3K class II (containing Vps38, endosomal) and Vps34-PI3K class I (containing Atg14, autophagosomal). Most PI(3)Ps are associated with endosomal membranes. In yeast, the endosomal localization of Vps34 and PI(3)P is tightly regulated by Vps21-module proteins. At yeast phagophore assembly site (PAS) or mammalian omegasomes, PI(3)P binds to WD-repeat protein interacting with phosphoinositide (WIPI) proteins to further recruit two conjugation systems, Atg5-Atg12·Atg16 and Atg8-PE (LC3-II), to initiate autophagy. However, the spatiotemporal regulation of PI(3)P during autophagy remains obscure. Therefore, in this study, we determined the effect of Vps21 on localization and interactions of Vps8, Vps34, Atg21, Atg8, and Atg16 upon autophagy induction. The results showed that Vps21 was required for successive colocalizations and interactions of Vps8-Vps34 and Vps34-Atg21 on endosomes, and Atg21-Atg8/Atg16 on the PAS. In addition to disrupted localization of the PI3K complex II subunits Vps34 and Vps38 on endosomes, the localization of the PI3K complex I subunits Vps34 and Atg14, as well as Atg21, was partly disrupted from the PAS in vps21∆ cells. The impaired PI3K-PI(3)P-Atg21-Atg16 axis in vps21∆ cells might delay autophagy, which is consistent with the delay of early autophagy when Atg21 was absent. This study provides the first insight into the upstream sequential regulation of the PI3K-PI(3)P-Atg21-Atg16 module by Vps21 in autophagy.
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Shen W, Luo P, Sun Y, Zhang W, Zhou N, Zhan H, Zhang Q, Shen J, Lin A, Cheng Q, Wang Q, Zhang J, Wang HH, Wei T. NRBF2 regulates the chemoresistance of small cell lung cancer by interacting with the P62 protein in the autophagy process. iScience 2022; 25:104471. [PMID: 35712081 PMCID: PMC9194155 DOI: 10.1016/j.isci.2022.104471] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 02/22/2022] [Accepted: 05/20/2022] [Indexed: 12/28/2022] Open
Abstract
Reversing chemotherapy resistance in small cell lung cancer (SCLC) is crucial to improve patient prognosis. The present study aims to investigate the underlying mechanisms in SCLC chemoresistance. We see that nuclear receptor binding factor 2 (NRBF2) is a poor prognostic factor in SCLC. The effects of NRBF2 on chemoresistance were determined in SCLC. The underlying molecular mechanisms of NRBF2 in the autophagy process in SCLC were examined. NRBF2 positively regulated autophagy, leading to drug resistance in SCLC. The MIT domain of NRBF2 directly interacted with the PB1 domain of P62. This interaction increased autophagic P62 body formation, revealing the regulatory role of NRBF2 in autophagy. Notably, NRBF2 was directly modulated by the transcription factor XRCC6. The MIT domain of NRBF2 interacts with the PB1 domain of P62 to regulate the autophagy process, resulting in SCLC chemoresistance. NRBF2 is likely a useful chemotherapy response marker and therapeutic target in SCLC. NRBF2 promoted the chemoresistance of SCLC in vitro and in vivo The chemoresistance induced by NRBF2 was mediated via autophagy in SCLC NRBF2 interacting with P62 contributed to autophagic P62 bodies' formation NRBF2 was regulated by XRCC6 via direct binding to the NRBF2 gene promoter
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Affiliation(s)
- Weitao Shen
- Department of Oncology, Zhujiang Hospital, Southern Medical University, 253 Industrial Avenue, Guangzhou 510282, Guangdong, People's Republic of China
| | - Peng Luo
- Department of Oncology, Zhujiang Hospital, Southern Medical University, 253 Industrial Avenue, Guangzhou 510282, Guangdong, People's Republic of China
| | - Yueqin Sun
- Department of Oncology, Zhujiang Hospital, Southern Medical University, 253 Industrial Avenue, Guangzhou 510282, Guangdong, People's Republic of China
| | - Wei Zhang
- Department of Oncology, Zhujiang Hospital, Southern Medical University, 253 Industrial Avenue, Guangzhou 510282, Guangdong, People's Republic of China
| | - Ningning Zhou
- Department of Medical Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510282, Guangdong, People's Republic of China
| | - Hongrui Zhan
- Department of Rehabilitation, The Fifth Affiliated Hospital of Sun Yat-sen University, Zhuhai 519000, Guangdong, People's Republic of China
| | - Qingxi Zhang
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou 510515, Guangdong, People's Republic of China
| | - Jie Shen
- Department of Oncology, Zhujiang Hospital, Southern Medical University, 253 Industrial Avenue, Guangzhou 510282, Guangdong, People's Republic of China
| | - Anqi Lin
- Department of Oncology, Zhujiang Hospital, Southern Medical University, 253 Industrial Avenue, Guangzhou 510282, Guangdong, People's Republic of China
| | - Quan Cheng
- Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha 410008, Hunan, People's Republic of China
| | - Qiongyao Wang
- Department of Oncology, Zhujiang Hospital, Southern Medical University, 253 Industrial Avenue, Guangzhou 510282, Guangdong, People's Republic of China
| | - Jian Zhang
- Department of Oncology, Zhujiang Hospital, Southern Medical University, 253 Industrial Avenue, Guangzhou 510282, Guangdong, People's Republic of China
| | - Hai-Hong Wang
- Department of Histology and Embryology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, Guangdong, People's Republic of China
| | - Ting Wei
- Department of Oncology, Zhujiang Hospital, Southern Medical University, 253 Industrial Avenue, Guangzhou 510282, Guangdong, People's Republic of China
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7
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Theater in the Self-Cleaning Cell: Intrinsically Disordered Proteins or Protein Regions Acting with Membranes in Autophagy. MEMBRANES 2022; 12:membranes12050457. [PMID: 35629783 PMCID: PMC9143426 DOI: 10.3390/membranes12050457] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 04/19/2022] [Accepted: 04/22/2022] [Indexed: 12/30/2022]
Abstract
Intrinsically disordered proteins and protein regions (IDPs/IDPRs) are mainly involved in signaling pathways, where fast regulation, temporal interactions, promiscuous interactions, and assemblies of structurally diverse components including membranes are essential. The autophagy pathway builds, de novo, a membrane organelle, the autophagosome, using carefully orchestrated interactions between proteins and lipid bilayers. Here, we discuss molecular mechanisms related to the protein disorder-based interactions of the autophagy machinery with membranes. We describe not only membrane binding phenomenon, but also examples of membrane remodeling processes including membrane tethering, bending, curvature sensing, and/or fragmentation of membrane organelles such as the endoplasmic reticulum, which is an important membrane source as well as cargo for autophagy. Summary of the current state of knowledge presented here will hopefully inspire new studies. A profound understanding of the autophagic protein–membrane interface is essential for advancements in therapeutic interventions against major human diseases, in which autophagy is involved including neurodegeneration, cancer as well as cardiovascular, metabolic, infectious, musculoskeletal, and other disorders.
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8
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Liu Y, Wei CH, Li C, Chen WZ, Zhu Y, Xu RS. Phosphoinositide-3-kinase regulatory subunit 4 participates in the occurrence and development of amyotrophic lateral sclerosis by regulating autophagy. Neural Regen Res 2021; 17:1609-1616. [PMID: 34916448 PMCID: PMC8771104 DOI: 10.4103/1673-5374.330621] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
The development of amyotrophic lateral sclerosis (ALS) may be related to the abnormal alterations of multiple proteins. Our previous study revealed that the expression of phosphoinositide-3-kinase regulatory subunit 4 (PIK3R4) was decreased in ALS. However, the role of PIK3R4 in ALS pathogenesis remains unknown. This study was the first to find that transfection of PC12 cells with small interfering RNA against the PIK3R4 gene significantly decreased the expression levels of PIK3R4 and the autophagy-related proteins p62 and LC3. Additionally, in vivo experiments revealed that the PIK3R4 protein was extensively expressed in the anterior horn, posterior horn, central canal, and areas surrounding the central canal in cervical, thoracic, and lumbar segments of the spinal cord in adult mice. PIK3R4 protein was mainly expressed in the neurons within the spinal lumbar segments. PIK3R4 and p62 expression levels were significantly decreased at both the pre-onset and onset stages of ALS disease in Tg(SOD1*G93A)1Gur mice compared with control mice, but these proteins were markedly increased at the progression stage. LC3 protein expression did not change during progression of ALS. These findings suggest that PIK3R4 likely participates in the prevention of ALS progression. This study was approved by the Ethics Committee for Animal Care and Use of Jiangxi Provincial People's Hospital, Affiliated People's Hospital of Nanchang University (approval No. 2020025) on March 26, 2020.
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Affiliation(s)
- Yue Liu
- Department of Neurology, First Affiliated Hospital of Nanchang Medical College, Jiangxi Provincial People's Hospital, Affiliated People's Hospital of Nanchang University, Nanchang, Jiangxi Province, China
| | - Cai-Hui Wei
- Department of Neurology, First Affiliated Hospital of Nanchang Medical College, Jiangxi Provincial People's Hospital, Affiliated People's Hospital of Nanchang University, Nanchang, Jiangxi Province, China
| | - Cheng Li
- Department of Neurology, First Affiliated Hospital of Nanchang Medical College, Jiangxi Provincial People's Hospital, Affiliated People's Hospital of Nanchang University, Nanchang, Jiangxi Province, China
| | - Wen-Zhi Chen
- Department of Neurology, First Affiliated Hospital of Nanchang Medical College, Jiangxi Provincial People's Hospital, Affiliated People's Hospital of Nanchang University, Nanchang, Jiangxi Province, China
| | - Yu Zhu
- Department of Neurology, First Affiliated Hospital of Nanchang Medical College, Jiangxi Provincial People's Hospital, Affiliated People's Hospital of Nanchang University, Nanchang, Jiangxi Province, China
| | - Ren-Shi Xu
- Department of Neurology, First Affiliated Hospital of Nanchang Medical College, Jiangxi Provincial People's Hospital, Affiliated People's Hospital of Nanchang University, Nanchang, Jiangxi Province, China
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9
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Ohashi Y. Activation Mechanisms of the VPS34 Complexes. Cells 2021; 10:cells10113124. [PMID: 34831348 PMCID: PMC8624279 DOI: 10.3390/cells10113124] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 11/09/2021] [Accepted: 11/09/2021] [Indexed: 01/18/2023] Open
Abstract
Phosphatidylinositol-3-phosphate (PtdIns(3)P) is essential for cell survival, and its intracellular synthesis is spatially and temporally regulated. It has major roles in two distinctive cellular pathways, namely, the autophagy and endocytic pathways. PtdIns(3)P is synthesized from phosphatidylinositol (PtdIns) by PIK3C3C/VPS34 in mammals or Vps34 in yeast. Pathway-specific VPS34/Vps34 activity is the consequence of the enzyme being incorporated into two mutually exclusive complexes: complex I for autophagy, composed of VPS34/Vps34-Vps15/Vps15-Beclin 1/Vps30-ATG14L/Atg14 (mammals/yeast), and complex II for endocytic pathways, in which ATG14L/Atg14 is replaced with UVRAG/Vps38 (mammals/yeast). Because of its involvement in autophagy, defects in which are closely associated with human diseases such as cancer and neurodegenerative diseases, developing highly selective drugs that target specific VPS34/Vps34 complexes is an essential goal in the autophagy field. Recent studies on the activation mechanisms of VPS34/Vps34 complexes have revealed that a variety of factors, including conformational changes, lipid physicochemical parameters, upstream regulators, and downstream effectors, greatly influence the activity of these complexes. This review summarizes and highlights each of these influences as well as clarifying key questions remaining in the field and outlining future perspectives.
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Affiliation(s)
- Yohei Ohashi
- MRC Laboratory of Molecular Biology, Protein and Nucleic Acid Chemistry Division, Francis Crick Avenue, Cambridge CB2 0QH, UK
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10
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Autophagy in Tumor Immunity and Viral-Based Immunotherapeutic Approaches in Cancer. Cells 2021; 10:cells10102672. [PMID: 34685652 PMCID: PMC8534833 DOI: 10.3390/cells10102672] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Revised: 09/22/2021] [Accepted: 09/27/2021] [Indexed: 01/09/2023] Open
Abstract
Autophagy is a fundamental catabolic process essential for the maintenance of cellular and tissue homeostasis, as well as directly contributing to the control of invading pathogens. Unsurprisingly, this process becomes critical in supporting cellular dysregulation that occurs in cancer, particularly the tumor microenvironments and their immune cell infiltration, ultimately playing a role in responses to cancer therapies. Therefore, understanding "cancer autophagy" could help turn this cellular waste-management service into a powerful ally for specific therapeutics. For instance, numerous regulatory mechanisms of the autophagic machinery can contribute to the anti-tumor properties of oncolytic viruses (OVs), which comprise a diverse class of replication-competent viruses with potential as cancer immunotherapeutics. In that context, autophagy can either: promote OV anti-tumor effects by enhancing infectivity and replication, mediating oncolysis, and inducing autophagic and immunogenic cell death; or reduce OV cytotoxicity by providing survival cues to tumor cells. These properties make the catabolic process of autophagy an attractive target for therapeutic combinations looking to enhance the efficacy of OVs. In this article, we review the complicated role of autophagy in cancer initiation and development, its effect on modulating OVs and immunity, and we discuss recent progress and opportunities/challenges in targeting autophagy to enhance oncolytic viral immunotherapy.
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11
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The deubiquitinase USP11 is a versatile and conserved regulator of autophagy. J Biol Chem 2021; 297:101263. [PMID: 34600886 PMCID: PMC8546420 DOI: 10.1016/j.jbc.2021.101263] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 09/16/2021] [Accepted: 09/28/2021] [Indexed: 01/18/2023] Open
Abstract
Autophagy is a major cellular quality control system responsible for the degradation of proteins and organelles in response to stress and damage to maintain homeostasis. Ubiquitination of autophagy-related proteins or regulatory components is important for the precise control of autophagy pathways. Here, we show that the deubiquitinase ubiquitin-specific protease 11 (USP11) restricts autophagy and that KO of USP11 in mammalian cells results in elevated autophagic flux. We also demonstrate that depletion of the USP11 homolog H34C03.2 in Caenorhabditis elegans triggers hyperactivation of autophagy and protects the animals against human amyloid-β peptide 42 aggregation-induced paralysis. USP11 coprecipitated with autophagy-specific class III phosphatidylinositol 3-kinase complex I and limited its interaction with nuclear receptor-binding factor 2, thus decreasing lipid kinase activity of class III phosphatidylinositol 3-kinase complex I and subsequent recruitment of effectors such as WD-repeat domain phosphoinositide-interacting proteins to the autophagosomal membrane. Accordingly, more WD-repeat domain phosphoinositide-interacting protein 2 puncta accumulated in USP11 KO cells. In addition, USP11 interacts with and stabilizes the serine/threonine kinase mechanistic target of rapamycin, thereby further contributing to the regulation of autophagy induction. Taken together, our data suggested that USP11 impinges on the autophagy pathway at multiple sites and that inhibiting USP11 alleviates symptoms of proteotoxicity, which is a major hallmark of neurodegenerative diseases.
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12
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Yu ZQ, Liu XM, Zhao D, Xu DD, Du LL. Visual detection of binary, ternary and quaternary protein interactions in fission yeast using a Pil1 co-tethering assay. J Cell Sci 2021; 134:272452. [PMID: 34499173 DOI: 10.1242/jcs.258774] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 09/03/2021] [Indexed: 01/28/2023] Open
Abstract
Protein-protein interactions are vital for executing nearly all cellular processes. To facilitate the detection of protein-protein interactions in living cells of the fission yeast Schizosaccharomyces pombe, here we present an efficient and convenient method termed the Pil1 co-tethering assay. In its basic form, we tether a bait protein to mCherry-tagged Pil1, which forms cortical filamentary structures, and examine whether a GFP-tagged prey protein colocalizes with the bait. We demonstrate that this assay is capable of detecting pairwise protein-protein interactions of cytosolic proteins and nuclear proteins. Furthermore, we show that this assay can be used for detecting not only binary protein-protein interactions, but also ternary and quaternary protein-protein interactions. Using this assay, we systematically characterized the protein-protein interactions in the Atg1 complex and in the phosphatidylinositol 3-kinase (PtdIns3K) complexes and found that Atg38 is incorporated into the PtdIns3K complex I via an Atg38-Vps34 interaction. Our data show that this assay is a useful and versatile tool and should be added to the routine toolbox of fission yeast researchers. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Zhong-Qiu Yu
- National Institute of Biological Sciences, 102206 Beijing, China
| | - Xiao-Man Liu
- National Institute of Biological Sciences, 102206 Beijing, China
| | - Dan Zhao
- National Institute of Biological Sciences, 102206 Beijing, China
| | - Dan-Dan Xu
- National Institute of Biological Sciences, 102206 Beijing, China
| | - Li-Lin Du
- National Institute of Biological Sciences, 102206 Beijing, China.,Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, 102206 Beijing, China
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13
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Matoba K, Noda NN. Structural catalog of core Atg proteins opens new era of autophagy research. J Biochem 2021; 169:517-525. [PMID: 33576807 DOI: 10.1093/jb/mvab017] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 01/27/2021] [Indexed: 12/21/2022] Open
Abstract
Autophagy, which is an evolutionarily conserved intracellular degradation system, involves de novo generation of autophagosomes that sequester and deliver diverse cytoplasmic materials to the lysosome for degradation. Autophagosome formation is mediated by approximately 20 core autophagy-related (Atg) proteins, which collaborate to mediate complicated membrane dynamics during autophagy. To elucidate the molecular functions of these Atg proteins in autophagosome formation, many researchers have tried to determine the structures of Atg proteins by using various structural biological methods. Although not sufficient, the basic structural catalog of all core Atg proteins was established. In this review article, we summarize structural biological studies of core Atg proteins, with an emphasis on recently unveiled structures, and describe the mechanistic breakthroughs in autophagy research that have derived from new structural information.
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Affiliation(s)
- Kazuaki Matoba
- Institute of Microbial Chemistry, 3-14-23 Kamiosaki, Shinagawa-ku, Tokyo 141-0021, Japan
| | - Nobuo N Noda
- Institute of Microbial Chemistry, 3-14-23 Kamiosaki, Shinagawa-ku, Tokyo 141-0021, Japan
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14
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Tran S, Fairlie WD, Lee EF. BECLIN1: Protein Structure, Function and Regulation. Cells 2021; 10:cells10061522. [PMID: 34204202 PMCID: PMC8235419 DOI: 10.3390/cells10061522] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/15/2021] [Accepted: 06/16/2021] [Indexed: 02/06/2023] Open
Abstract
BECLIN1 is a well-established regulator of autophagy, a process essential for mammalian survival. It functions in conjunction with other proteins to form Class III Phosphoinositide 3-Kinase (PI3K) complexes to generate phosphorylated phosphatidylinositol (PtdIns), lipids essential for not only autophagy but other membrane trafficking processes. Over the years, studies have elucidated the structural, biophysical, and biochemical properties of BECLIN1, which have shed light on how this protein functions to allosterically regulate these critical processes of autophagy and membrane trafficking. Here, we review these findings and how BECLIN1’s diverse protein interactome regulates it, as well as its impact on organismal physiology.
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Affiliation(s)
- Sharon Tran
- Olivia Newton-John Cancer Research Institute, Heidelberg, VIC 3084, Australia;
- School of Cancer Medicine, La Trobe University, Bundoora, VIC 3086, Australia
| | - W. Douglas Fairlie
- Olivia Newton-John Cancer Research Institute, Heidelberg, VIC 3084, Australia;
- School of Cancer Medicine, La Trobe University, Bundoora, VIC 3086, Australia
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3086, Australia
- Correspondence: (W.D.F.); (E.F.L.)
| | - Erinna F. Lee
- Olivia Newton-John Cancer Research Institute, Heidelberg, VIC 3084, Australia;
- School of Cancer Medicine, La Trobe University, Bundoora, VIC 3086, Australia
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3086, Australia
- Correspondence: (W.D.F.); (E.F.L.)
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15
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Mercer TJ, Ohashi Y, Boeing S, Jefferies HBJ, De Tito S, Flynn H, Tremel S, Zhang W, Wirth M, Frith D, Snijders AP, Williams RL, Tooze SA. Phosphoproteomic identification of ULK substrates reveals VPS15-dependent ULK/VPS34 interplay in the regulation of autophagy. EMBO J 2021; 40:e105985. [PMID: 34121209 PMCID: PMC8280838 DOI: 10.15252/embj.2020105985] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 03/29/2021] [Accepted: 04/21/2021] [Indexed: 02/06/2023] Open
Abstract
Autophagy is a process through which intracellular cargoes are catabolised inside lysosomes. It involves the formation of autophagosomes initiated by the serine/threonine kinase ULK and class III PI3 kinase VPS34 complexes. Here, unbiased phosphoproteomics screens in mouse embryonic fibroblasts deleted for Ulk1/2 reveal that ULK loss significantly alters the phosphoproteome, with novel high confidence substrates identified including VPS34 complex member VPS15 and AMPK complex subunit PRKAG2. We identify six ULK-dependent phosphorylation sites on VPS15, mutation of which reduces autophagosome formation in cells and VPS34 activity in vitro. Mutation of serine 861, the major VPS15 phosphosite, decreases both autophagy initiation and autophagic flux. Analysis of VPS15 knockout cells reveals two novel ULK-dependent phenotypes downstream of VPS15 removal that can be partially recapitulated by chronic VPS34 inhibition, starvation-independent accumulation of ULK substrates and kinase activity-regulated recruitment of autophagy proteins to ubiquitin-positive structures.
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Affiliation(s)
- Thomas John Mercer
- Molecular Cell Biology of Autophagy, The Francis Crick Institute, London, UK
| | - Yohei Ohashi
- MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Stefan Boeing
- Bioinformatics and Biostatistics, The Francis Crick Institute, London, UK
| | | | - Stefano De Tito
- Molecular Cell Biology of Autophagy, The Francis Crick Institute, London, UK.,Institute of Experimental Endocrinology and Oncology (IEOS), National Research Council, Naples, Italy
| | - Helen Flynn
- Institute of Experimental Endocrinology and Oncology (IEOS), National Research Council, Naples, Italy
| | | | - Wenxin Zhang
- Molecular Cell Biology of Autophagy, The Francis Crick Institute, London, UK
| | - Martina Wirth
- Molecular Cell Biology of Autophagy, The Francis Crick Institute, London, UK
| | - David Frith
- Proteomics, The Francis Crick Institute, London, UK
| | | | | | - Sharon A Tooze
- Molecular Cell Biology of Autophagy, The Francis Crick Institute, London, UK
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16
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Melia TJ, Lystad AH, Simonsen A. Autophagosome biogenesis: From membrane growth to closure. J Cell Biol 2021; 219:151729. [PMID: 32357219 PMCID: PMC7265318 DOI: 10.1083/jcb.202002085] [Citation(s) in RCA: 155] [Impact Index Per Article: 51.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 04/04/2020] [Accepted: 04/06/2020] [Indexed: 12/14/2022] Open
Abstract
Autophagosome biogenesis involves de novo formation of a membrane that elongates to sequester cytoplasmic cargo and closes to form a double-membrane vesicle (an autophagosome). This process has remained enigmatic since its initial discovery >50 yr ago, but our understanding of the mechanisms involved in autophagosome biogenesis has increased substantially during the last 20 yr. Several key questions do remain open, however, including, What determines the site of autophagosome nucleation? What is the origin and lipid composition of the autophagosome membrane? How is cargo sequestration regulated under nonselective and selective types of autophagy? This review provides key insight into the core molecular mechanisms underlying autophagosome biogenesis, with a specific emphasis on membrane modeling events, and highlights recent conceptual advances in the field.
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Affiliation(s)
- Thomas J Melia
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT
| | - Alf H Lystad
- Department of Molecular Medicine, Institute of Basic Medical Sciences and Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Anne Simonsen
- Department of Molecular Medicine, Institute of Basic Medical Sciences and Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
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17
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Ohashi Y. Class III phosphatidylinositol 3-kinase complex I subunit NRBF2/Atg38 - from cell and structural biology to health and disease. Autophagy 2021; 17:3897-3907. [PMID: 33459128 PMCID: PMC8726667 DOI: 10.1080/15548627.2021.1872240] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Macroautophagy/autophagy is triggered by various starvation and stress conditions. The phospholipid phosphatidylinositol-3-phosphate (PtdIns3P) is essential for the formation of the autophagosome both in yeast and mammals. The class III phosphatidylinositol 3-kinase, PIK3C3C in humans or Vps34 in yeast, produces PtdIns3P by phosphorylating the 3'-OH position of phosphatidylinositol (PtdIns). In order to synthesize PtdIns3P for the initiation of autophagy, PIK3C3/Vps34 has a heterotetrameric core, the PIK3C3 complex I (hereafter complex I) composed of PIK3C3/Vps34, PIK3R4/Vps15, BECN1/Vps30, and ATG14/Atg14. A fifth component of complex I, NRBF2 in mammals and Atg38 in yeast, was found and has been characterized in the past decade. The field has been expanding from cell and structural biology to mouse model and cohort studies. Here I will summarize the structures and models of complex I binding NRBF2/Atg38, its intracellular roles, and its involvement in health and disease. Along with this expansion of the field, different conclusions have been drawn in several topics. I will clarify what has and has not been agreed, and what is to be clarified in the future.
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Affiliation(s)
- Yohei Ohashi
- Division of Protein and Nucleic Acid Chemistry, MRC Laboratory of Molecular Biology, Cambridge, UK
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18
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The G-Protein Rab5A Activates VPS34 Complex II, a Class III PI3K, by a Dual Regulatory Mechanism. Biophys J 2020; 119:2205-2218. [PMID: 33137306 DOI: 10.1016/j.bpj.2020.10.028] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 10/04/2020] [Accepted: 10/07/2020] [Indexed: 02/07/2023] Open
Abstract
VPS34 complex II (VPS34CII) is a 386-kDa assembly of the lipid kinase subunit VPS34 and three regulatory subunits that altogether function as a prototypical class III phosphatidylinositol-3-kinase (PI3K). When the active VPS34CII complex is docked to the cytoplasmic surface of endosomal membranes, it phosphorylates its substrate lipid (phosphatidylinositol, PI) to generate the essential signaling lipid phosphatidylinositol-3-phosphate (PI3P). In turn, PI3P recruits an array of signaling proteins containing PI3P-specific targeting domains (including FYVE, PX, and PROPPINS) to the membrane surface, where they initiate key cell processes. In endocytosis and early endosome development, net VPS34CII-catalyzed PI3P production is greatly amplified by Rab5A, a small G protein of the Ras GTPase superfamily. Moreover, VPS34CII and Rab5A are each strongly linked to multiple human diseases. Thus, a molecular understanding of the mechanism by which Rab5A activates lipid kinase activity will have broad impacts in both signaling biology and medicine. Two general mechanistic models have been proposed for small G protein activation of PI3K lipid kinases. 1) In the membrane recruitment mechanism, G protein association increases the density of active kinase on the membrane. And 2) in the allosteric activation mechanism, G protein allosterically triggers an increase in the specific activity (turnover rate) of the membrane-bound kinase molecule. This study employs an in vitro single-molecule approach to elucidate the mechanism of GTP-Rab5A-associated VPS34CII kinase activation in a reconstituted GTP-Rab5A-VPS34CII-PI3P-PX signaling pathway on a target membrane surface. The findings reveal that both membrane recruitment and allosteric mechanisms make important contributions to the large increase in VPS34CII kinase activity and PI3P production triggered by membrane-anchored GTP-Rab5A. Notably, under near-physiological conditions in the absence of other activators, membrane-anchored GTP-Rab5A provides strong, virtually binary on-off switching and is required for VPS34CII membrane binding and PI3P production.
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19
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Ohashi Y, Tremel S, Masson GR, McGinney L, Boulanger J, Rostislavleva K, Johnson CM, Niewczas I, Clark J, Williams RL. Membrane characteristics tune activities of endosomal and autophagic human VPS34 complexes. eLife 2020; 9:58281. [PMID: 32602837 PMCID: PMC7326497 DOI: 10.7554/elife.58281] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Accepted: 06/04/2020] [Indexed: 12/14/2022] Open
Abstract
The lipid kinase VPS34 orchestrates diverse processes, including autophagy, endocytic sorting, phagocytosis, anabolic responses and cell division. VPS34 forms various complexes that help adapt it to specific pathways, with complexes I and II being the most prominent ones. We found that physicochemical properties of membranes strongly modulate VPS34 activity. Greater unsaturation of both substrate and non-substrate lipids, negative charge and curvature activate VPS34 complexes, adapting them to their cellular compartments. Hydrogen/deuterium exchange mass spectrometry (HDX-MS) of complexes I and II on membranes elucidated structural determinants that enable them to bind membranes. Among these are the Barkor/ATG14L autophagosome targeting sequence (BATS), which makes autophagy-specific complex I more active than the endocytic complex II, and the Beclin1 BARA domain. Interestingly, even though Beclin1 BARA is common to both complexes, its membrane-interacting loops are critical for complex II, but have only a minor role for complex I.
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Affiliation(s)
- Yohei Ohashi
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, United Kingdom
| | - Shirley Tremel
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, United Kingdom
| | - Glenn Robert Masson
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, United Kingdom
| | - Lauren McGinney
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, United Kingdom
| | - Jerome Boulanger
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, United Kingdom
| | - Ksenia Rostislavleva
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, United Kingdom
| | - Christopher M Johnson
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, United Kingdom
| | | | | | - Roger L Williams
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, United Kingdom
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20
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Cai CZ, Yang C, Zhuang XX, Yuan NN, Wu MY, Tan JQ, Song JX, Cheung KH, Su H, Wang YT, Tang BS, Behrends C, Durairajan SSK, Yue Z, Li M, Lu JH. NRBF2 is a RAB7 effector required for autophagosome maturation and mediates the association of APP-CTFs with active form of RAB7 for degradation. Autophagy 2020; 17:1112-1130. [PMID: 32543313 DOI: 10.1080/15548627.2020.1760623] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
NRBF2 is a component of the class III phosphatidylinositol 3-kinase (PtdIns3K) complex. Our previous study has revealed its role in regulating ATG14-associated PtdIns3K activity for autophagosome initiation. In this study, we revealed an unknown mechanism by which NRBF2 modulates autophagosome maturation and APP-C-terminal fragment (CTF) degradation. Our data showed that NRBF2 localized at autolysosomes, and loss of NRBF2 impaired autophagosome maturation. Mechanistically, NRBF2 colocalizes with RAB7 and is required for generation of GTP-bound RAB7 by interacting with RAB7 GEF CCZ1-MON1A and maintaining the GEF activity. Specifically, NRBF2 regulates CCZ1-MON1A interaction with PI3KC3/VPS34 and CCZ1-associated PI3KC3 kinase activity, which are required for CCZ1-MON1A GEF activity. Finally, we showed that NRBF2 is involved in APP-CTF degradation and amyloid beta peptide production by maintaining the interaction between APP and the CCZ1-MON1A-RAB7 module to facilitate the maturation of APP-containing vesicles. Overall, our study revealed a pivotal role of NRBF2 as a new RAB7 effector in modulating autophagosome maturation, providing insight into the molecular mechanism of NRBF2-PtdIns3K in regulating RAB7 activity for macroautophagy/autophagy maturation and Alzheimer disease-associated protein degradation..Abbreviations: 3xTg AD, triple transgenic mouse for Alzheimer disease; Aβ, amyloid beta peptide; Aβ1-40, amyloid beta peptide 1-40; Aβ1-42, amyloid beta peptide 1-42; AD, Alzheimer disease; APP, amyloid beta precursor protein; APP-CTFs, APP C-terminal fragments; ATG, autophagy related; ATG5, autophagy related 5; ATG7, autophagy related 7; ATG14, autophagy related 14; CCD, coiled-coil domain; CCZ1, CCZ1 homolog, vacuolar protein trafficking and biogenesis associated; CHX, cycloheximide; CQ, chloroquine; DAPI, 4',6-diamidino-2-phenylindole; dCCD, delete CCD; dMIT, delete MIT; FYCO1, FYVE and coiled-coil domain autophagy adaptor 1; FYVE, Fab1, YGL023, Vps27, and EEA1; GAP, GTPase-activating protein; GDP, guanine diphosphate; GEF, guanine nucleotide exchange factor; GTP, guanine triphosphate; GTPase, guanosine triphosphatase; HOPS, homotypic fusion and vacuole protein sorting; ILVs, endosomal intralumenal vesicles; KD, knockdown; KO, knockout; LAMP1, lysosomal associated membrane protein 1; MAP1LC3/LC3, microtubule associated protein 1 light chain 3; MLVs, multilamellar vesicles; MON1A, MON1 homolog A, secretory trafficking associated; NRBF2, nuclear receptor binding factor 2; PtdIns3K, class III phosphatidylinositol 3-kinase; PtdIns3P, phosphatidylinositol-3-phosphate; RILP, Rab interacting lysosomal protein; SNARE, soluble N-ethylmaleimide-sensitive factor attachment protein receptor; SQSTM1/p62, sequestosome 1; UVRAG, UV radiation resistance associated; VPS, vacuolar protein sorting; WT, wild type.
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Affiliation(s)
- Cui-Zan Cai
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau SAR, China
| | - Chuanbin Yang
- Mr. And Mrs. Ko Chi Ming Centre for Parkinson's Disease Research, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong SAR, China
| | - Xu-Xu Zhuang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau SAR, China
| | - Ning-Ning Yuan
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau SAR, China
| | - Ming-Yue Wu
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau SAR, China
| | - Jie-Qiong Tan
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Ju-Xian Song
- Mr. And Mrs. Ko Chi Ming Centre for Parkinson's Disease Research, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong SAR, China.,Medical College of Acupuncture-Moxibustion and Rehabilitation, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - King-Ho Cheung
- Mr. And Mrs. Ko Chi Ming Centre for Parkinson's Disease Research, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong SAR, China
| | - Huanxing Su
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau SAR, China
| | - Yi-Tao Wang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau SAR, China
| | - Bei-Sha Tang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Christian Behrends
- Munich Cluster for Systems Neurology (Synergy), Ludwig-Maximilians-Universität München, München, Germany
| | - Siva Sundara Kumar Durairajan
- Mr. And Mrs. Ko Chi Ming Centre for Parkinson's Disease Research, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong SAR, China.,Division of Mycobiology and Neurodegenerative Disease Research, Department of Microbiology, School of Life Sciences, Central University of Tamil Nadu, Tiruvarur, India
| | - Zhenyu Yue
- Department of Neurology and Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Min Li
- Mr. And Mrs. Ko Chi Ming Centre for Parkinson's Disease Research, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong SAR, China
| | - Jia-Hong Lu
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau SAR, China
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21
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Emerging roles of ATG proteins and membrane lipids in autophagosome formation. Cell Discov 2020; 6:32. [PMID: 32509328 PMCID: PMC7248066 DOI: 10.1038/s41421-020-0161-3] [Citation(s) in RCA: 129] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 03/21/2020] [Indexed: 12/12/2022] Open
Abstract
Autophagosome biogenesis is a dynamic membrane event, which is executed by the sequential function of autophagy-related (ATG) proteins. Upon autophagy induction, a cup-shaped membrane structure appears in the cytoplasm, then elongates sequestering cytoplasmic materials, and finally forms a closed double membrane autophagosome. However, how this complex vesicle formation event is strictly controlled and achieved is still enigmatic. Recently, there is accumulating evidence showing that some ATG proteins have the ability to directly interact with membranes, transfer lipids between membranes and regulate lipid metabolism. A novel role for various membrane lipids in autophagosome formation is also emerging. Here, we highlight past and recent key findings on the function of ATG proteins related to autophagosome biogenesis and consider how ATG proteins control this dynamic membrane formation event to organize the autophagosome by collaborating with membrane lipids.
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22
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Takáts S, Lévay L, Boda A, Tóth S, Simon-Vecsei Z, Rubics A, Varga Á, Lippai M, Lőrincz P, Glatz G, Juhász G. The Warburg Micro Syndrome-associated Rab3GAP-Rab18 module promotes autolysosome maturation through the Vps34 Complex I. FEBS J 2020; 288:190-211. [PMID: 32248620 DOI: 10.1111/febs.15313] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Revised: 02/10/2020] [Accepted: 03/26/2020] [Indexed: 12/23/2022]
Abstract
Warburg micro syndrome (WMS) is a hereditary autosomal neuromuscular disorder in humans caused by mutations in Rab18, Rab3GAP1, or Rab3GAP2 genes. Rab3GAP1/2 forms a heterodimeric complex, which acts as a guanosine nucleotide exchange factor and activates Rab18. Although the genetic causes of WMS are known, it is still unclear whether loss of the Rab3GAP-Rab18 module affects neuronal or muscle cell physiology or both, and how. In this work, we characterize a Rab3GAP2 mutant Drosophila line to establish a novel animal model for WMS. Similarly to symptoms of WMS, loss of Rab3GAP2 leads to highly decreased motility in Drosophila that becomes more serious with age. We demonstrate that these mutant flies are defective for autophagic degradation in multiple tissues including fat cells and muscles. Loss of Rab3GAP-Rab18 module members leads to perturbed autolysosome morphology due to destabilization of Rab7-positive autophagosomal and late endosomal compartments and perturbation of lysosomal biosynthetic transport. Importantly, overexpression of UVRAG or loss of Atg14, two alternative subunits of the Vps34/PI3K (vacuole protein sorting 34/phosphatidylinositol 3-kinase) complexes in fat cells, mimics the autophagic phenotype of Rab3GAP-Rab18 module loss. We find that GTP-bound Rab18 binds to Atg6/Beclin1, a permanent subunit of Vps34 complexes. Finally, we show that Rab3GAP2 and Rab18 are present on autophagosomal and autolysosomal membranes and colocalize with Vps34 Complex I subunits. Our data suggest that the Rab3GAP-Rab18 module regulates autolysosomal maturation through its interaction with the Vps34 Complex I, and perturbed autophagy due to loss of the Rab3GAP-Rab18 module may contribute to the development of WMS.
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Affiliation(s)
- Szabolcs Takáts
- Department of Anatomy, Cell and Developmental Biology, ELTE Eötvös Loránd University, Budapest, Hungary.,Premium Postdoctorate Research Program, Hungarian Academy of Sciences, Budapest, Hungary
| | - Luca Lévay
- Department of Anatomy, Cell and Developmental Biology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Attila Boda
- Department of Anatomy, Cell and Developmental Biology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Sarolta Tóth
- Department of Anatomy, Cell and Developmental Biology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Zsófia Simon-Vecsei
- Department of Anatomy, Cell and Developmental Biology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - András Rubics
- Department of Anatomy, Cell and Developmental Biology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Ágnes Varga
- Department of Anatomy, Cell and Developmental Biology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Mónika Lippai
- Department of Anatomy, Cell and Developmental Biology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Péter Lőrincz
- Department of Anatomy, Cell and Developmental Biology, ELTE Eötvös Loránd University, Budapest, Hungary.,Premium Postdoctorate Research Program, Hungarian Academy of Sciences, Budapest, Hungary
| | - Gábor Glatz
- Department of Anatomy, Cell and Developmental Biology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Gábor Juhász
- Department of Anatomy, Cell and Developmental Biology, ELTE Eötvös Loránd University, Budapest, Hungary.,Institute of Genetics, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, Hungary
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23
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Popelka H. Dancing while self-eating: Protein intrinsic disorder in autophagy. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2020; 174:263-305. [PMID: 32828468 DOI: 10.1016/bs.pmbts.2020.03.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Autophagy is a major catabolic pathway that must be tightly regulated to maintain cellular homeostasis. Protein intrinsic disorder provides a very suitable conformation for regulation; accordingly, the molecular machinery of autophagy is significantly enriched in intrinsically disordered proteins and protein regions (IDPs/IDPRs). Despite experimental challenges that the characterization of IDPRs encounters, remarkable progress has been made in recent years in revealing various roles of IDPs/IDPRs in autophagy. This chapter describes the autophagy pathway from a specific point of view, that of IDPRs. It focuses in detail on structural and mechanistic functions in autophagy that are executed by disordered regions. Via a description of autophagosome biogenesis, linking the cargo to the autophagy machinery, as well as a discussion of certain post-translational regulations, this review reveals many indispensable roles of IDPRs in the functional autophagy pathway. Devastating pathologies such as neurodegeneration, cancer, or diabetes have been linked to a malfunction in IDPs/IDPRs. The same pathologies are associated with dysfunctional autophagy, indicating that autophagic IDPRs may be a paramount causative factor. Several disease-related mechanisms of the autophagy pathway involving protein intrinsic disorder are reported in this chapter, to illustrate a wide-ranging potential of IDPRs in the therapeutic modulation of autophagy.
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Affiliation(s)
- Hana Popelka
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, United States.
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24
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Yu ZQ, Sun LL, Jiang ZD, Liu XM, Zhao D, Wang HT, He WZ, Dong MQ, Du LL. Atg38-Atg8 interaction in fission yeast establishes a positive feedback loop to promote autophagy. Autophagy 2020; 16:2036-2051. [PMID: 31941401 PMCID: PMC7595586 DOI: 10.1080/15548627.2020.1713644] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Macroautophagy (autophagy) is driven by the coordinated actions of core autophagy-related (Atg) proteins. Atg8, the core Atg protein generally considered acting most downstream, has recently been shown to interact with other core Atg proteins via their Atg8-family-interacting motifs (AIMs). However, the extent, functional consequence, and evolutionary conservation of such interactions remain inadequately understood. Here, we show that, in the fission yeast Schizosaccharomyces pombe, Atg38, a subunit of the phosphatidylinositol 3-kinase (PtdIns3K) complex I, interacts with Atg8 via an AIM, which is highly conserved in Atg38 proteins of fission yeast species, but not conserved in Atg38 proteins of other species. This interaction recruits Atg38 to Atg8 on the phagophore assembly site (PAS) and consequently enhances PAS accumulation of the PtdIns3K complex I and Atg proteins acting downstream of the PtdIns3K complex I, including Atg8. The disruption of the Atg38-Atg8 interaction leads to the reduction of autophagosome size and autophagic flux. Remarkably, the loss of this interaction can be compensated by an artificial Atg14-Atg8 interaction. Our findings demonstrate that the Atg38-Atg8 interaction in fission yeast establishes a positive feedback loop between Atg8 and the PtdIns3K complex I to promote efficient autophagosome formation, underscore the prevalence and diversity of AIM-mediated connections within the autophagic machinery, and reveal unforeseen flexibility of such connections. Abbreviations: AIM: Atg8-family-interacting motif; AP-MS: affinity purification coupled with mass spectrometry; Atg: autophagy-related; FLIP: fluorescence loss in photobleaching; PAS: phagophore assembly site; PB: piggyBac; PE: phosphatidylethanolamine; PtdIns3K: phosphatidylinositol 3-kinase; PtdIns3P: phosphatidylinositol 3-phosphate.
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Affiliation(s)
- Zhong-Qiu Yu
- National Institute of Biological Sciences , Beijing, China.,PTN Graduate Program, School of Life Sciences, Peking University , Beijing, China
| | - Ling-Ling Sun
- National Institute of Biological Sciences , Beijing, China
| | - Zhao-Di Jiang
- National Institute of Biological Sciences , Beijing, China
| | - Xiao-Man Liu
- National Institute of Biological Sciences , Beijing, China
| | - Dan Zhao
- National Institute of Biological Sciences , Beijing, China
| | - Hai-Tao Wang
- National Institute of Biological Sciences , Beijing, China
| | - Wan-Zhong He
- National Institute of Biological Sciences , Beijing, China
| | - Meng-Qiu Dong
- National Institute of Biological Sciences , Beijing, China.,Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University , Beijing, China
| | - Li-Lin Du
- National Institute of Biological Sciences , Beijing, China.,Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University , Beijing, China
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25
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Zhao Y, Zhang Y, Zhang J, Zhang X, Yang G. Molecular Mechanism of Autophagy: Its Role in the Therapy of Alzheimer's Disease. Curr Neuropharmacol 2020; 18:720-739. [PMID: 31934838 PMCID: PMC7536828 DOI: 10.2174/1570159x18666200114163636] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 11/04/2019] [Accepted: 01/11/2020] [Indexed: 12/12/2022] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder of progressive dementia that is characterized by the accumulation of beta-amyloid (Aβ)-containing neuritic plaques and intracellular Tau protein tangles. This distinctive pathology indicates that the protein quality control is compromised in AD. Autophagy functions as a "neuronal housekeeper" that eliminates aberrant protein aggregates by wrapping then into autophagosomes and delivering them to lysosomes for degradation. Several studies have suggested that autophagy deficits in autophagy participate in the accumulation and propagation of misfolded proteins (including Aβ and Tau). In this review, we summarize current knowledge of autophagy in the pathogenesis of AD, as well as some pathways targeting the restoration of autophagy. Moreover, we discuss how these aspects can contribute to the development of disease-modifying therapies in AD.
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Affiliation(s)
| | | | | | | | - Guofeng Yang
- Address correspondence to this author at the Department of Geriatrics, Second Hospital of Hebei Medical University, 215 Hepingxi Road, Shijiazhuang, 050000, China; Tel: +86-311-66636243; E-mail:
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26
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Lai LTF, Ye H, Zhang W, Jiang L, Lau WCY. Structural Biology and Electron Microscopy of the Autophagy Molecular Machinery. Cells 2019; 8:E1627. [PMID: 31842460 PMCID: PMC6952983 DOI: 10.3390/cells8121627] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 12/06/2019] [Accepted: 12/10/2019] [Indexed: 12/30/2022] Open
Abstract
Autophagy is a highly regulated bulk degradation process that plays a key role in the maintenance of cellular homeostasis. During autophagy, a double membrane-bound compartment termed the autophagosome is formed through de novo nucleation and assembly of membrane sources to engulf unwanted cytoplasmic components and targets them to the lysosome or vacuole for degradation. Central to this process are the autophagy-related (ATG) proteins, which play a critical role in plant fitness, immunity, and environmental stress response. Over the past few years, cryo-electron microscopy (cryo-EM) and single-particle analysis has matured into a powerful and versatile technique for the structural determination of protein complexes at high resolution and has contributed greatly to our current understanding of the molecular mechanisms underlying autophagosome biogenesis. Here we describe the plant-specific ATG proteins and summarize recent structural and mechanistic studies on the protein machinery involved in autophagy initiation with an emphasis on those by single-particle analysis.
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Affiliation(s)
- Louis Tung Faat Lai
- School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Hao Ye
- School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Wenxin Zhang
- School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Liwen Jiang
- School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
- CUHK Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen 518057, China
| | - Wilson Chun Yu Lau
- School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
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27
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Lachance V, Wang Q, Sweet E, Choi I, Cai CZ, Zhuang XX, Zhang Y, Jiang JL, Blitzer RD, Bozdagi-Gunal O, Zhang B, Lu JH, Yue Z. Autophagy protein NRBF2 has reduced expression in Alzheimer's brains and modulates memory and amyloid-beta homeostasis in mice. Mol Neurodegener 2019; 14:43. [PMID: 31775806 PMCID: PMC6882183 DOI: 10.1186/s13024-019-0342-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Accepted: 10/31/2019] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Dysfunctional autophagy is implicated in Alzheimer's Disease (AD) pathogenesis. The alterations in the expression of many autophagy related genes (ATGs) have been reported in AD brains; however, the disparity of the changes confounds the role of autophagy in AD. METHODS To further understand the autophagy alteration in AD brains, we analyzed transcriptomic (RNAseq) datasets of several brain regions (BA10, BA22, BA36 and BA44 in 223 patients compared to 59 healthy controls) and measured the expression of 130 ATGs. We used autophagy-deficient mouse models to assess the impact of the identified ATGs depletion on memory, autophagic activity and amyloid-β (Aβ) production. RESULTS We observed significant downregulation of multiple components of two autophagy kinase complexes BECN1-PIK3C3 and ULK1/2-FIP200 specifically in the parahippocampal gyrus (BA36). Most importantly, we demonstrated that deletion of NRBF2, a component of the BECN1-PIK3C3 complex, which also associates with ULK1/2-FIP200 complex, impairs memory in mice, alters long-term potentiation (LTP), reduces autophagy in mouse hippocampus, and promotes Aβ accumulation. Furthermore, AAV-mediated NRBF2 overexpression in the hippocampus not only rescues the impaired autophagy and memory deficits in NRBF2-depleted mice, but also reduces β-amyloid levels and improves memory in an AD mouse model. CONCLUSIONS Our data not only implicates NRBF2 deficiency as a risk factor for cognitive impairment associated with AD, but also support the idea of NRBF2 as a potential therapeutic target for AD.
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Affiliation(s)
- Véronik Lachance
- Department of Neurology, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Qian Wang
- Department of Neurology, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.,Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Eric Sweet
- Department of Neurology, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.,Departments of Psychiatry and Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.,Present Address: Department of Biology, West Chester University, West Chester, PA, 19383, USA
| | - Insup Choi
- Department of Neurology, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Cui-Zan Cai
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, Macau SAR, China
| | - Xu-Xu Zhuang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, Macau SAR, China
| | - Yuanxi Zhang
- Department of Neurology, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Jessica Li Jiang
- Department of Neurology, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Robert D Blitzer
- Departments of Psychiatry and Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Ozlem Bozdagi-Gunal
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.,Present Address: Department of Psychiatry, Rutgers New Jersey Medical School, Newark, NJ, 07103, USA
| | - Bin Zhang
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Jia-Hong Lu
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, Macau SAR, China.
| | - Zhenyu Yue
- Department of Neurology, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
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28
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Zhou C, Qian X, Hu M, Zhang R, Liu N, Huang Y, Yang J, Zhang J, Bai H, Yang Y, Wang Y, Ali D, Michalak M, Chen XZ, Tang J. STYK1 promotes autophagy through enhancing the assembly of autophagy-specific class III phosphatidylinositol 3-kinase complex I. Autophagy 2019; 16:1786-1806. [PMID: 31696776 DOI: 10.1080/15548627.2019.1687212] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Macroautophagy/autophagy plays key roles in development, oncogenesis, and cardiovascular and metabolic diseases. Autophagy-specific class III phosphatidylinositol 3-kinase complex I (PtdIns3K-C1) is essential for autophagosome formation. However, the regulation of this complex formation requires further investigation. Here, we discovered that STYK1 (serine/threonine/tyrosine kinase 1), a member of the receptor tyrosine kinases (RTKs) family, is a new upstream regulator of autophagy. We discovered that STYK1 facilitated autophagosome formation in human cells and zebrafish, which was characterized by elevated LC3-II and lowered SQSTM1/p62 levels and increased puncta formation by several marker proteins, such as ATG14, WIPI1, and ZFYVE1. Moreover, we observed that STYK1 directly binds to the PtdIns3K-C1 complex as a homodimer. The binding with this complex was promoted by Tyr191 phosphorylation, by means of which the kinase activity of STYK1 was elevated. We also demonstrated that STYK1 elevated the serine phosphorylation of BECN1, thereby decreasing the interaction between BECN1 and BCL2. Furthermore, we found that STYK1 preferentially facilitated the assembly of the PtdIns3K-C1 complex and was required for PtdIns3K-C1 complex kinase activity. Taken together, our findings provide new insights into autophagy induction and reveal evidence of novel crosstalk between the components of RTK signaling and autophagy. Abbreviations: AICAR: 5-aminoimidazole-4-carboxamide ribonucleotide; AMPK: adenosine 5'-monophosphate (AMP)-activated protein kinase; ATG: autophagy related; ATP: adenosine triphosphate; BCL2: BCL2 apoptosis regulator; BECN1: beclin 1; Bre A: brefeldin A; Co-IP: co-immunoprecipitation; CRISPR: clustered regularly interspaced short palindromic repeats; DAPI: 4',6-diamidino-2-phenylindole; EBSS: Earle's balanced salt solution; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; GFP: green fluorescent protein; GSEA: gene set enrichment analysis; MAP1LC3/LC3, microtubule associated protein 1 light chain 3; MAPK8/JNK1: mitogen-activated protein kinase 8; mRFP: monomeric red fluorescent protein; MTOR: mechanistic target of rapamycin kinase; MTT: 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide; PIK3C3: phosphatidylinositol 3-kinase catalytic subunit type 3; PIK3R4: phosphoinositide-3-kinase regulatory subunit 4; qRT-PCR: quantitative reverse transcription PCR; RACK1: receptor for activated C kinase 1; RUBCN: rubicon autophagy regulator; siRNA: small interfering RNA; SQSTM1: sequestosome 1; STYK1/NOK: serine/threonine/tyrosine kinase 1; TCGA: The Cancer Genome Atlas; Ub: ubiquitin; ULK1: unc-51 like autophagy activating kinase 1; UVRAG: UV radiation resistance associated; WIPI1: WD repeat domain, phosphoinositide interacting 1; ZFYVE1: zinc finger FYVE-type containing 1.
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Affiliation(s)
- Cefan Zhou
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology , Wuhan, China.,The State Key Laboratory of Virology, College of Life Sciences, Wuhan University , Wuhan, Hubei, China
| | - Xuehong Qian
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology , Wuhan, China
| | - Miao Hu
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology , Wuhan, China
| | - Rui Zhang
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology , Wuhan, China
| | - Nanxi Liu
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology , Wuhan, China
| | - Yuan Huang
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology , Wuhan, China
| | - Jing Yang
- Department of Biological Sciences, Boler-Parseghian Center for Rare and Neglected Diseases, Harper Cancer Research Institute, University of Notre Dame , Notre Dame, IN, USA
| | - Juan Zhang
- Department of Gastroenterology, First Affiliated Hospital of Xi`an Jiaotong University , Xi`an, Shanxi, China
| | - Hua Bai
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology , Wuhan, China
| | - Yuyan Yang
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology , Wuhan, China
| | - Yefu Wang
- The State Key Laboratory of Virology, College of Life Sciences, Wuhan University , Wuhan, Hubei, China
| | - Declan Ali
- Department of Biological Sciences, University of Alberta , Edmonton, Alberta, Canada
| | - Marek Michalak
- Department of Biochemistry, University of Alberta , Edmonton, Alberta, Canada
| | - Xing-Zhen Chen
- Membrane Protein Disease Research Group, Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta , Edmonton, AB, Canada
| | - Jingfeng Tang
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology , Wuhan, China
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29
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Structural pathway for allosteric activation of the autophagic PI 3-kinase complex I. Proc Natl Acad Sci U S A 2019; 116:21508-21513. [PMID: 31591221 DOI: 10.1073/pnas.1911612116] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Autophagy induction by starvation and stress involves the enzymatic activation of the class III phosphatidylinositol (PI) 3-kinase complex I (PI3KC3-C1). The inactive basal state of PI3KC3-C1 is maintained by inhibitory contacts between the VPS15 protein kinase and VPS34 lipid kinase domains that restrict the conformation of the VPS34 activation loop. Here, the proautophagic MIT domain-containing protein NRBF2 was used to map the structural changes leading to activation. Cryoelectron microscopy was used to visualize a 2-step PI3KC3-C1 activation pathway driven by NRFB2 MIT domain binding. Binding of a single NRBF2 MIT domain bends the helical solenoid of the VPS15 scaffold, displaces the protein kinase domain of VPS15, and releases the VPS34 kinase domain from the inhibited conformation. Binding of a second MIT stabilizes the VPS34 lipid kinase domain in an active conformation that has an unrestricted activation loop and is poised for access to membranes.
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30
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Vps15 is critical to mediate autophagy in AngII treated HUVECs probably by PDK1/PKC signaling pathway. Life Sci 2019; 233:116701. [DOI: 10.1016/j.lfs.2019.116701] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 07/24/2019] [Accepted: 07/25/2019] [Indexed: 12/29/2022]
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31
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Balancing mTOR Signaling and Autophagy in the Treatment of Parkinson's Disease. Int J Mol Sci 2019; 20:ijms20030728. [PMID: 30744070 PMCID: PMC6387269 DOI: 10.3390/ijms20030728] [Citation(s) in RCA: 136] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 02/01/2019] [Accepted: 02/01/2019] [Indexed: 12/18/2022] Open
Abstract
The mammalian target of rapamycin (mTOR) signaling pathway plays a critical role in regulating cell growth, proliferation, and life span. mTOR signaling is a central regulator of autophagy by modulating multiple aspects of the autophagy process, such as initiation, process, and termination through controlling the activity of the unc51-like kinase 1 (ULK1) complex and vacuolar protein sorting 34 (VPS34) complex, and the intracellular distribution of TFEB/TFE3 and proto-lysosome tubule reformation. Parkinson’s disease (PD) is a serious, common neurodegenerative disease characterized by dopaminergic neuron loss in the substantia nigra pars compacta (SNpc) and the accumulation of Lewy bodies. An increasing amount of evidence indicates that mTOR and autophagy are critical for the pathogenesis of PD. In this review, we will summarize recent advances regarding the roles of mTOR and autophagy in PD pathogenesis and treatment. Further characterizing the dysregulation of mTOR pathway and the clinical translation of mTOR modulators in PD may offer exciting new avenues for future drug development.
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32
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Abstract
Since I started doing scientific research, I've been fascinated by the interplay of protein structure and dynamics and how they together mediate protein function. A particular area of interest has been in understanding the mechanistic basis of how lipid-signaling enzymes function on membrane surfaces. In this award lecture article, I will describe my laboratory's studies on the structure and dynamics of lipid-signaling enzymes on membrane surfaces. This is important, as many lipid-signaling enzymes are regulated through dynamic regulatory mechanisms that control their enzymatic activity. This article will discuss my continued enthusiasm in using a synergistic application of hydrogen-deuterium exchange MS (HDX-MS) with other structural biology techniques to probe the mechanistic basis for how membrane-localized signaling enzymes are regulated and how these approaches can be used to understand how they are misregulated in disease. I will discuss specific examples of how we have used HDX-MS to study phosphoinositide kinases and the protein kinase Akt. An important focus will be on a description of how HDX-MS can be used as a powerful tool to optimize the design of constructs for X-ray crystallography and EM. The use of a diverse toolbox of biophysical methods has revealed novel insight into the complex and varied regulatory networks that control the function of lipid-signaling enzymes and enabled unique insight into the mechanics of membrane recruitment.
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Affiliation(s)
- John E Burke
- From the Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 2Y2, Canada
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33
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Chang C, Young LN, Morris KL, von Bülow S, Schöneberg J, Yamamoto-Imoto H, Oe Y, Yamamoto K, Nakamura S, Stjepanovic G, Hummer G, Yoshimori T, Hurley JH. Bidirectional Control of Autophagy by BECN1 BARA Domain Dynamics. Mol Cell 2019; 73:339-353.e6. [PMID: 30581147 PMCID: PMC6450660 DOI: 10.1016/j.molcel.2018.10.035] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 09/15/2018] [Accepted: 10/19/2018] [Indexed: 12/11/2022]
Abstract
Membrane targeting of the BECN1-containing class III PI 3-kinase (PI3KC3) complexes is pivotal to the regulation of autophagy. The interaction of PI3KC3 complex II and its ubiquitously expressed inhibitor, Rubicon, was mapped to the first β sheet of the BECN1 BARA domain and the UVRAG BARA2 domain by hydrogen-deuterium exchange and cryo-EM. These data suggest that the BARA β sheet 1 unfolds to directly engage the membrane. This mechanism was confirmed using protein engineering, giant unilamellar vesicle assays, and molecular simulations. Using this mechanism, a BECN1 β sheet-1 derived peptide activates both PI3KC3 complexes I and II, while HIV-1 Nef inhibits complex II. These data reveal how BECN1 switches on and off PI3KC3 binding to membranes. The observations explain how PI3KC3 inhibition by Rubicon, activation by autophagy-inducing BECN1 peptides, and inhibition by HIV-1 Nef are mediated by the switchable ability of the BECN1 BARA domain to partially unfold and insert into membranes.
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Affiliation(s)
- Chunmei Chang
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Lindsey N Young
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA; Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Kyle L Morris
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Sören von Bülow
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, 60438 Frankfurt/M, Germany
| | - Johannes Schöneberg
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Hitomi Yamamoto-Imoto
- Department of Genetics, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan
| | - Yukako Oe
- Department of Genetics, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan
| | - Kentaro Yamamoto
- Department of Genetics, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan
| | - Shuhei Nakamura
- Department of Genetics, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan
| | - Goran Stjepanovic
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA; Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Gerhard Hummer
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, 60438 Frankfurt/M, Germany; Institute of Biophysics, Goethe University, 60438 Frankfurt/M, Germany
| | - Tamotsu Yoshimori
- Department of Genetics, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan
| | - James H Hurley
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA; Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
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34
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Osawa T, Alam JM, Noda NN. Membrane-binding domains in autophagy. Chem Phys Lipids 2019; 218:1-9. [DOI: 10.1016/j.chemphyslip.2018.11.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 10/31/2018] [Accepted: 11/07/2018] [Indexed: 02/07/2023]
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35
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Li W, Zhang L. Regulation of ATG and Autophagy Initiation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1206:41-65. [PMID: 31776979 DOI: 10.1007/978-981-15-0602-4_2] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
ATG is involved in multiple processes of autophagosome formation, including the initial phase of autophagy. The mammalian autophagy complex-ULK1 complex is composed of ULK1, FIP200, ATG13 and ATG101, and the yeast autophagy initiation complex-ATG1 complex is composed of ATG1, ATG13, ATG17, ATG29 and ATG31. After this complex is activated, it binds and phosphorylates ATG9 on the vesicles. Then PI3KC3-C1 (yeast: ATG34: ATG15: ATG6: ATG14 or mammal animal: ATG34: ATG15: BECN1: ATG14L) is recruited to the PAS. Further, ATG12-ATG5-ATG16 complex is localized on PAS (Yeast) or localized on the outer surface of the membrane (mammal) and makes binding of ATG8 (LC3) with PE to form ATG8-PE complex, promoting autophagic membrane elongation, closure and formation autophagosome and autophagosome lysosome.
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Affiliation(s)
- Wen Li
- Department of Immunology, School of Basic Medical Science, Shandong University, 44# Wenhua Xi Road, Jinan, 250012, China
| | - Lining Zhang
- Department of Immunology, School of Basic Medical Science, Shandong University, 44# Wenhua Xi Road, Jinan, 250012, China.
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36
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Ding X, Zhang X, Otegui MS. Plant autophagy: new flavors on the menu. CURRENT OPINION IN PLANT BIOLOGY 2018; 46:113-121. [PMID: 30267997 DOI: 10.1016/j.pbi.2018.09.004] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Revised: 08/28/2018] [Accepted: 09/04/2018] [Indexed: 06/08/2023]
Abstract
Autophagy mediates the delivery of cytoplasmic content to vacuoles or lysosomes for degradation or storage. The best characterized autophagy route called macroautophagy involves the sequestration of cargo in double-membrane autophagosomes and is conserved in eukaryotes, including plants. Recently, several new receptors, some of them plant-specific, that select cargo for macroautophagy have been identified. Some of these receptors appear to participate in regulation of competing catabolic pathways, for example proteasome-mediated versus autophagic degradation under specific stress conditions. Vacuolar microautophagy, a process by which the vacuole directly engulf cytoplasmic material, also occurs in plants but its underlying molecular mechanisms are yet to be elucidated.
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Affiliation(s)
- Xinxin Ding
- Department of Botany, 430 Lincoln Drive, University of Wisconsin-Madison, WI 53706, United States; Laboratory of Molecular and Cellular Biology, 1525 Linden Drive, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Xiaoguo Zhang
- Department of Botany, 430 Lincoln Drive, University of Wisconsin-Madison, WI 53706, United States; Laboratory of Molecular and Cellular Biology, 1525 Linden Drive, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Marisa S Otegui
- Department of Botany, 430 Lincoln Drive, University of Wisconsin-Madison, WI 53706, United States; Laboratory of Molecular and Cellular Biology, 1525 Linden Drive, University of Wisconsin-Madison, Madison, WI 53706, United States; Department of Genetics, 405 Henry Mall, University of Wisconsin-Madison, Madison, WI 53706, United States.
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37
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Ohashi Y, Tremel S, Williams RL. VPS34 complexes from a structural perspective. J Lipid Res 2018; 60:229-241. [PMID: 30397185 PMCID: PMC6358306 DOI: 10.1194/jlr.r089490] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 10/24/2018] [Indexed: 02/07/2023] Open
Abstract
VPS34 phosphorylates phosphatidylinositol to produce PtdIns3P and is the progenitor of the phosphoinositide 3-kinase (PI3K) family. VPS34 has a simpler domain organization than class I PI3Ks, which belies the complexity of its quaternary organization, with the enzyme always functioning within larger assemblies. PtdIns3P recruits specific recognition modules that are common in protein-sorting pathways, such as autophagy and endocytic sorting. It is best characterized in two heterotetramers, complexes I and II. Complex I is composed of VPS34, VPS15, Beclin 1, and autophagy-related gene (ATG)14L, whereas complex II replaces ATG14L with UVRAG. Because VPS34 can form a component of several distinct complexes, it enables independent regulation of various pathways that are controlled by PtdIns3P. Complexes I and II are critical for early events in autophagy and endocytic sorting, respectively. Autophagy has a complex association with cancer. In early stages, it inhibits tumorigenesis, but in later stages, it acts as a survival factor for tumors. Recently, various disease-associated somatic mutations were found in genes encoding complex I and II subunits. Lipid kinase activities of the complexes are also influenced by posttranslational modifications (PTMs). Mapping PTMs and somatic mutations on three-dimensional models of the complexes suggests mechanisms for how these affect VPS34 activity.
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Affiliation(s)
- Yohei Ohashi
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Shirley Tremel
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Roger L Williams
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
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38
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Structural Basis for Regulation of Phosphoinositide Kinases and Their Involvement in Human Disease. Mol Cell 2018; 71:653-673. [DOI: 10.1016/j.molcel.2018.08.005] [Citation(s) in RCA: 117] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 06/22/2018] [Accepted: 07/30/2018] [Indexed: 01/09/2023]
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Zhuang X, Chung KP, Luo M, Jiang L. Autophagosome Biogenesis and the Endoplasmic Reticulum: A Plant Perspective. TRENDS IN PLANT SCIENCE 2018; 23:677-692. [PMID: 29929776 DOI: 10.1016/j.tplants.2018.05.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 04/19/2018] [Accepted: 05/01/2018] [Indexed: 05/20/2023]
Abstract
The autophagosome is a double-membrane compartment formed during autophagy that sequesters and delivers cargoes for their degradation or recycling into the vacuole. Analyses of the AuTophaGy-related (ATG) proteins have unveiled dynamic mechanisms for autophagosome biogenesis. Recent advances in plant autophagy research highlight a complex interplay between autophagosome biogenesis and the endoplasmic reticulum (ER): on the one hand ER serves as a membrane source for autophagosome initiation and a signaling platform for autophagy regulation; on the other hand ER turnover is connected to selective autophagy. We provide here an integrated view of ER-based autophagosome biogenesis in plants in comparison with the newest findings in yeast and mammals, with an emphasis on the hierarchy of the core ATG proteins, ATG9 trafficking, and ER-resident regulators in autophagy.
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Affiliation(s)
- Xiaohong Zhuang
- Center for Cell and Developmental Biology, State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China; These authors contributed equally to this work.
| | - Kin Pan Chung
- Center for Cell and Developmental Biology, State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China; Current address: Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1 14476, Potsdam-Golm, Germany; These authors contributed equally to this work
| | - Mengqian Luo
- Center for Cell and Developmental Biology, State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Liwen Jiang
- Center for Cell and Developmental Biology, State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China; The Chinese University of Hong Kong Shenzhen Research Institute, Shenzhen, China.
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Targeting the potent Beclin 1-UVRAG coiled-coil interaction with designed peptides enhances autophagy and endolysosomal trafficking. Proc Natl Acad Sci U S A 2018; 115:E5669-E5678. [PMID: 29866835 PMCID: PMC6016778 DOI: 10.1073/pnas.1721173115] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Beclin 1 is an essential autophagy protein. Through its coiled-coil domain, Beclin 1 recruits two modulators, Atg14L and UVRAG, to form Atg14L- or UVRAG-containing Beclin 1–Vps34 subcomplexes responsible for Vps34-dependent membrane trafficking processes including autophagy and endosomal trafficking. Our structural study of the Beclin 1–UVRAG coiled-coil complex reveals a strengthened interface to maintain potent Beclin 1–UVRAG interaction. This potency is essential for UVRAG to outcompete Atg14L and enhance Vps34-dependent endosomal trafficking. Our designed peptides can target the Beclin 1 coiled-coil domain, promote Atg14L– and UVRAG–Beclin 1 interaction, induce autophagy, and significantly enhance endolysosomal degradation of the EGF receptor. Our results testify to the feasibility of targeting Beclin 1 to regulate both autophagy and endosomal trafficking. The Beclin 1–Vps34 complex, known as “mammalian class III PI3K,” plays essential roles in membrane-mediated transport processes including autophagy and endosomal trafficking. Beclin 1 acts as a scaffolding molecule for the complex and readily transits from its metastable homodimeric state to interact with key modulators such as Atg14L or UVRAG and form functionally distinct Atg14L/UVRAG-containing Beclin 1–Vps34 subcomplexes. The Beclin 1–Atg14L/UVRAG interaction relies critically on their coiled-coil domains, but the molecular mechanism remains poorly understood. We determined the crystal structure of Beclin 1–UVRAG coiled-coil complex and identified a strengthened interface with both hydrophobic pairings and electrostatically complementary interactions. This structure explains why the Beclin 1–UVRAG interaction is more potent than the metastable Beclin 1 homodimer. Potent Beclin 1–UVRAG interaction is functionally significant because it renders UVRAG more competitive than Atg14L in Beclin 1 binding and is critical for promoting endolysosomal trafficking. UVRAG coiled-coil mutants with weakened Beclin 1 binding do not outcompete Atg14L and fail to promote endolysosomal degradation of the EGF receptor (EGFR). We designed all-hydrocarbon stapled peptides that specifically targeted the C-terminal part of the Beclin 1 coiled-coil domain to interfere with its homodimerization. One such peptide reduced Beclin 1 self-association, promoted Beclin 1–Atg14L/UVRAG interaction, increased autophagic flux, and enhanced EGFR degradation. Our results demonstrate that the targeting Beclin 1 coiled-coil domain with designed peptides to induce the redistribution of Beclin 1 among its self-associated form or Atg14L/UVRAG-containing complexes enhances both autophagy and endolysosomal trafficking.
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Abstract
Autophagy is a highly conserved process and is essential for the maintenance of cellular homeostasis. Autophagy occurs at a basal level in all cells, but it can be up-regulated during stress, starvation, or infection. Misregulation of autophagy has been linked to various disorders, including cancer, neurodegeneration, and immune diseases. Here, we discuss the essential proteins acting in the formation of an autophagosome, with a focus on the ULK and VPS34 kinase complexes, phosphatidylinositol 3-phosphate effector proteins, and the transmembrane autophagy-related protein ATG9. The function and regulation of these and other autophagy-related proteins acting during formation will be addressed, in particular during amino acid starvation.
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Affiliation(s)
- Thomas J Mercer
- From the Molecular Cell Biology of Autophagy Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, United Kingdom
| | - Andrea Gubas
- From the Molecular Cell Biology of Autophagy Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, United Kingdom
| | - Sharon A Tooze
- From the Molecular Cell Biology of Autophagy Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, United Kingdom
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Usón I, Sheldrick GM. An introduction to experimental phasing of macromolecules illustrated by SHELX; new autotracing features. Acta Crystallogr D Struct Biol 2018; 74:106-116. [PMID: 29533236 PMCID: PMC5947774 DOI: 10.1107/s2059798317015121] [Citation(s) in RCA: 114] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 10/17/2017] [Indexed: 11/10/2022] Open
Abstract
For the purpose of this article, experimental phasing is understood to mean the determination of macromolecular structures by exploiting small intensity differences of Friedel opposites and possibly of reflections measured at different wavelengths or for heavy-atom derivatives, without the use of specific structural models. The SHELX programs provide a robust and efficient route for routine structure solution by the SAD, MAD and related methods, but involve a number of simplifying assumptions that may limit their applicability in borderline cases. The substructure atoms (i.e. those with significant anomalous scattering) are first located by direct methods, and the experimental data are then used to estimate phase shifts that are added to the substructure phases to obtain starting phases for the native reflections. These are then improved by density modification and, if the resolution of the data and the type of structure permit, polyalanine tracing. A number of extensions to the tracing algorithm are discussed; these are designed to improve its performance at low resolution. Given native data to 2.5 Å resolution or better, a correlation coefficient greater than 25% between the structure factors calculated from such a trace and the native data is usually a good indication that the structure has been solved.
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Affiliation(s)
- Isabel Usón
- Structural Biology, IBMB–CSIC, Baldiri Reixach 13-15, 08028 Barcelona, Spain
- ICREA, Baldiri Pg. Lluís Companys 23, 08010 Barcelona, Spain
| | - George M. Sheldrick
- Department of Structural Chemistry, Georg-August Universität Göttingen, Tammannstrasse 4, 37077 Göttingen, Germany
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43
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Nascimbeni AC, Codogno P, Morel E. Local detection of PtdIns3P at autophagosome biogenesis membrane platforms. Autophagy 2017; 13:1602-1612. [PMID: 28813193 DOI: 10.1080/15548627.2017.1341465] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Phosphatidylinositol 3-phosphate (PtdIns3P) is a key player of membrane trafficking regulation, mostly synthesized by the PIK3C3 lipid kinase. The presence of PtdIns3P on endosomes has been demonstrated; however, the role and dynamics of the pool of PtdIns3P dedicated to macroautophagy/autophagy remains elusive. Here we addressed this question by studying the mobilization of PtdIns3P in time and space during autophagosome biogenesis. We compared different dyes known to specifically detect PtdIns3P by fluorescence microscopy analysis, based on PtdIns3P-binding FYVE and PX domains, and show that these transfected dyes induce defects in endosomal dynamics as well as artificial and sustained autophagosome formation. In contrast, indirect use of recombinant FYVE enabled us to track and discriminate endosomal and autophagosomal pools of PtdIns3P. We used this method to analyze localization and dynamics of PtdIns3P subdomains on the endoplasmic reticulum, at sites of pre-autophagosome associated protein recruitment such as the PtdIns3P-binding ZFYVE1/DFCP1 and WIPI2 autophagy regulators. This approach thus revealed the presence of a specific pool of PtdIns3P at the site where autophagosome assembly is initiated.
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Affiliation(s)
- Anna Chiara Nascimbeni
- a Cell Biology Department , Institut Necker-Enfants Malades (INEM) , INSERM U1151-CNRS UMR 8253, Paris , France.,b Université Paris Descartes-Sorbonne Paris Cité , Paris , France
| | - Patrice Codogno
- a Cell Biology Department , Institut Necker-Enfants Malades (INEM) , INSERM U1151-CNRS UMR 8253, Paris , France.,b Université Paris Descartes-Sorbonne Paris Cité , Paris , France
| | - Etienne Morel
- a Cell Biology Department , Institut Necker-Enfants Malades (INEM) , INSERM U1151-CNRS UMR 8253, Paris , France.,b Université Paris Descartes-Sorbonne Paris Cité , Paris , France
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Stjepanovic G, Baskaran S, Lin MG, Hurley JH. Vps34 Kinase Domain Dynamics Regulate the Autophagic PI 3-Kinase Complex. Mol Cell 2017; 67:528-534.e3. [PMID: 28757208 DOI: 10.1016/j.molcel.2017.07.003] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 05/16/2017] [Accepted: 06/30/2017] [Indexed: 12/29/2022]
Abstract
The class III phosphatidylinositol 3-kinase complex I (PI3KC3-C1) is required for the initiation of essentially all macroautophagic processes. PI3KC3-C1 consists of the lipid kinase catalytic subunit VPS34, the VPS15 scaffold, and the regulatory BECN1 and ATG14 subunits. The VPS34 catalytic domain and BECN1:ATG14 subcomplex do not touch, and it is unclear how allosteric signals are transmitted to VPS34. We used EM and crosslinking mass spectrometry to dissect five conformational substates of the complex, including one in which the VPS34 catalytic domain is dislodged from the complex but remains tethered by an intrinsically disordered linker. A "leashed" construct prevented dislodging without interfering with the other conformations, blocked enzyme activity in vitro, and blocked autophagy induction in yeast cells. This pinpoints the dislodging and tethering of the VPS34 catalytic domain, and its regulation by VPS15, as a master allosteric switch in autophagy induction.
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Affiliation(s)
- Goran Stjepanovic
- Department of Molecular and Cell Biology and California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA; Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Sulochanadevi Baskaran
- Department of Molecular and Cell Biology and California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Mary G Lin
- Department of Molecular and Cell Biology and California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA
| | - James H Hurley
- Department of Molecular and Cell Biology and California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA; Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
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Abstract
Autophagy is the process of cellular self-eating by a double-membrane organelle, the autophagosome. A range of signaling processes converge on two protein complexes to initiate autophagy: the ULK1 (unc51-like autophagy activating kinase 1) protein kinase complex and the PI3KC3-C1 (class III phosphatidylinositol 3-kinase complex I) lipid kinase complex. Some 90% of the mass of these large protein complexes consists of noncatalytic domains and subunits, and the ULK1 complex has essential noncatalytic activities. Structural studies of these complexes have shed increasing light on the regulation of their catalytic and noncatalytic activities in autophagy initiation. The autophagosome is thought to nucleate from vesicles containing the integral membrane protein Atg9 (autophagy-related 9), COPII (coat protein complex II) vesicles, and possibly other sources. In the wake of reconstitution and super-resolution imaging studies, we are beginning to understand how the ULK1 and PI3KC3-C1 complexes might coordinate the nucleation and fusion of Atg9 and COPII vesicles at the start of autophagosome biogenesis.
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Affiliation(s)
- James H Hurley
- Department of Molecular and Cell Biology and California Institute of Quantitative Biosciences, University of California, Berkeley, California, and Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California, 94720;
| | - Lindsey N Young
- Department of Molecular and Cell Biology and California Institute of Quantitative Biosciences, University of California, Berkeley, California, and Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California, 94720;
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Keller CW, Lünemann JD. Autophagy and Autophagy-Related Proteins in CNS Autoimmunity. Front Immunol 2017; 8:165. [PMID: 28289410 PMCID: PMC5326760 DOI: 10.3389/fimmu.2017.00165] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 02/02/2017] [Indexed: 12/13/2022] Open
Abstract
Autophagy comprises a heterogeneous group of cellular pathways that enables eukaryotic cells to deliver cytoplasmic constituents for lysosomal degradation, to recycle nutrients, and to survive during starvation. In addition to these primordial functions, autophagy has emerged as a key mechanism in orchestrating innate and adaptive immune responses and to shape CD4+ T cell immunity through delivery of peptides to major histocompatibility complex (MHC) class II-containing compartments (MIICs). Individual autophagy proteins additionally modulate expression of MHC class I molecules for CD8+ T cell activation. The emergence and expansion of autoreactive CD4+ and CD8+ T cells are considered to play a key role in the pathogenesis of multiple sclerosis (MS) and its animal model experimental autoimmune encephalomyelitis. Expression of the essential autophagy-related protein 5 (Atg5), which supports T lymphocyte survival and proliferation, is increased in T cells isolated from blood or brain tissues from patients with relapsing-remitting MS. Whether Atgs contribute to the activation of autoreactive T cells through autophagy-mediated antigen presentation is incompletely understood. Here, we discuss the complex functions of autophagy proteins and pathways in regulating T cell immunity and its potential role in the development and progression of MS.
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Affiliation(s)
- Christian W Keller
- Institute of Experimental Immunology, Laboratory of Neuroinflammation, University of Zürich , Zürich , Switzerland
| | - Jan D Lünemann
- Institute of Experimental Immunology, Laboratory of Neuroinflammation, University of Zürich, Zürich, Switzerland; Department of Neurology, University Hospital Zürich, Zürich, Switzerland
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47
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Nascimbeni AC, Codogno P, Morel E. Phosphatidylinositol-3-phosphate in the regulation of autophagy membrane dynamics. FEBS J 2017; 284:1267-1278. [PMID: 27973739 DOI: 10.1111/febs.13987] [Citation(s) in RCA: 134] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Revised: 11/15/2016] [Accepted: 12/07/2016] [Indexed: 12/30/2022]
Abstract
Phosphatidylinositol-3-phosphate (PI3P) is a key player in membrane dynamics and trafficking regulation. Most PI3P is associated with endosomal membranes and with the autophagosome preassembly machinery, presumably at the endoplasmic reticulum. The enzyme responsible for most PI3P synthesis, VPS34 and proteins such as Beclin1 and ATG14L that regulate PI3P levels are positive modulators of autophagy initiation. It had been assumed that a local PI3P pool was present at autophagosomes and preautophagosomal structures, such as the omegasome and the phagophore. This was recently confirmed by the demonstration that PI3P-binding proteins participate in the complex sequence of signalling that results in autophagosome assembly and activity. Here we summarize the historical discoveries of PI3P lipid kinase involvement in autophagy, and we discuss the proposed role of PI3P during autophagy, notably during the autophagosome biogenesis sequence.
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Affiliation(s)
- Anna Chiara Nascimbeni
- Institut Necker-Enfants Malades (INEM), INSERM U1151-CNRS UMR 8253, Paris, France.,Université Paris Descartes-Sorbonne Paris Cité, France
| | - Patrice Codogno
- Institut Necker-Enfants Malades (INEM), INSERM U1151-CNRS UMR 8253, Paris, France.,Université Paris Descartes-Sorbonne Paris Cité, France
| | - Etienne Morel
- Institut Necker-Enfants Malades (INEM), INSERM U1151-CNRS UMR 8253, Paris, France.,Université Paris Descartes-Sorbonne Paris Cité, France
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48
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Suzuki H, Osawa T, Fujioka Y, Noda NN. Structural biology of the core autophagy machinery. Curr Opin Struct Biol 2016; 43:10-17. [PMID: 27723509 DOI: 10.1016/j.sbi.2016.09.010] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Revised: 09/13/2016] [Accepted: 09/21/2016] [Indexed: 02/08/2023]
Abstract
In autophagy, which is an intracellular degradation system that is conserved among eukaryotes, degradation targets are sequestered through the de novo synthesis of a double-membrane organelle, the autophagosome, which delivers them to the lysosomes for degradation. The core autophagy machinery comprising 18 autophagy-related (Atg) proteins in yeast plays an essential role in autophagosome formation; however, the molecular role of each Atg factor and the mechanism of autophagosome formation remain elusive. Recent years have seen remarkable progress in structural biological studies on the core autophagy machinery, opening new avenues for autophagy research. This review summarizes recent advances in structural biological and mechanistic studies on the core autophagy machinery and discusses the molecular mechanisms of autophagosome formation.
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Affiliation(s)
- Hironori Suzuki
- Institute of Microbial Chemistry, Microbial Chemistry Research Foundation, 3-14-23 Kamiosaki, Shinagawa-ku, Tokyo 141-0021, Japan
| | - Takuo Osawa
- Institute of Microbial Chemistry, Microbial Chemistry Research Foundation, 3-14-23 Kamiosaki, Shinagawa-ku, Tokyo 141-0021, Japan
| | - Yuko Fujioka
- Institute of Microbial Chemistry, Microbial Chemistry Research Foundation, 3-14-23 Kamiosaki, Shinagawa-ku, Tokyo 141-0021, Japan
| | - Nobuo N Noda
- Institute of Microbial Chemistry, Microbial Chemistry Research Foundation, 3-14-23 Kamiosaki, Shinagawa-ku, Tokyo 141-0021, Japan.
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