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Ke PY. Molecular Mechanism of Autophagosome-Lysosome Fusion in Mammalian Cells. Cells 2024; 13:500. [PMID: 38534345 DOI: 10.3390/cells13060500] [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: 02/09/2024] [Revised: 03/11/2024] [Accepted: 03/12/2024] [Indexed: 03/28/2024] Open
Abstract
In eukaryotes, targeting intracellular components for lysosomal degradation by autophagy represents a catabolic process that evolutionarily regulates cellular homeostasis. The successful completion of autophagy initiates the engulfment of cytoplasmic materials within double-membrane autophagosomes and subsequent delivery to autolysosomes for degradation by acidic proteases. The formation of autolysosomes relies on the precise fusion of autophagosomes with lysosomes. In recent decades, numerous studies have provided insights into the molecular regulation of autophagosome-lysosome fusion. In this review, an overview of the molecules that function in the fusion of autophagosomes with lysosomes is provided. Moreover, the molecular mechanism underlying how these functional molecules regulate autophagosome-lysosome fusion is summarized.
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Affiliation(s)
- Po-Yuan Ke
- Department of Biochemistry & Molecular Biology, Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
- Liver Research Center, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan
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2
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Li Z, Dai F, Zhu R, Zhang Y, Chen J, Chen L, Liu H, Cheng Y. Dysregulation of CREB5 Impairs Decidualization and Maternal-Fetal Interactions by Inhibiting Autophagy in Recurrent Spontaneous Abortion. Reprod Sci 2024:10.1007/s43032-024-01474-2. [PMID: 38424407 DOI: 10.1007/s43032-024-01474-2] [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: 11/13/2023] [Accepted: 01/31/2024] [Indexed: 03/02/2024]
Abstract
BACKGROUND Clinically, recurrent spontaneous abortion (RSA) is a pregnancy illness that is difficult to treat. Impaired decidualization is a documented cause of RSA, but the etiology and mechanism are still unknown. cAMP-responsive element binding protein 5 (CREB5) is a member of the ATF/CREB family. CREB5 has been reported to be related to pathological pregnancy, but there are few related studies on this topic in patients with RSA, and the underlying mechanism is unclear. METHODS We collected decidual tissues from RSA patients and healthy pregnant women to measure the expression level of CREB5, PRL, IGFBP1, ATG5, LC3B, and SQSTM/p62. Then, the changes in CREB5 expression and autophagy levels were measured in human endometrial stromal cells (hESCs) during decidualization. The expression levels of PRL and IGFBP1 were tested in sh-CREB5/ov-CREB5 hESCs after decidualization induction, and the autophagy level in sh-CREB5/ov-CREB5 hESCs was measured without decidualization induction. The decidualization ability of sh-CREB5 and ov-CREB5 hESCs treated with an autophagy inducer or inhibitor was measured. To investigate the effect of CREB5 in hESCs on the invasion and migration of HTR8/SVneo cells, we performed a coculture experiment. Finally, we examined the expression of CREB5 and autophagy key proteins in mouse decidual tissues by constructing an abortion mouse model. RESULTS In our study, we found that the expression of CREB5 was unusually elevated in the uterine decidua of RSA patients, but the expression of PRL, IGFBP1, and autophagy were decreased. During the decidualization of hESCs, the expression of CREB5 gradually decreases in a time-dependent manner with increasing autophagy. Moreover, by knocking down or overexpressing CREB5 in hESCs, it was found that CREB5 can impair decidualization and reduce autophagy in hESCs. Furthermore, the damage caused by CREB5 in terms of decidualization can be reversed by the addition of an autophagy inducer (rapamycin). In addition, CREB5 can increase the secretion of proteins (IL-1β and TGF-β1) in hESCs to inhibit trophoblast invasion and migration. CONCLUSIONS Our data support the supposition that CREB5 disturbs the decidualization of endometrial stromal cells and interactions at the maternal-fetal interface by inhibiting autophagy and that its abnormal upregulation and dysfunction may lead to RSA. It may function as a diagnostic and therapeutic target for RSA. Similarly, we found that in the spontaneous abortion mouse model, the expression of CREB5 in the decidual tissue of the abortion group was significantly increased, and autophagy was decreased.
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Affiliation(s)
- Zhidian Li
- Department of Obstetrics and Gynecology, Renmin Hospital of Wuhan University, 99 Zhang Zhidong Road, Wuhan, Hubei, 430060, People's Republic of China
| | - Fangfang Dai
- Department of Obstetrics and Gynecology, Renmin Hospital of Wuhan University, 99 Zhang Zhidong Road, Wuhan, Hubei, 430060, People's Republic of China
| | - Ronghui Zhu
- Department of Obstetrics and Gynecology, Renmin Hospital of Wuhan University, 99 Zhang Zhidong Road, Wuhan, Hubei, 430060, People's Republic of China
| | - Yuwei Zhang
- Department of Obstetrics and Gynecology, Renmin Hospital of Wuhan University, 99 Zhang Zhidong Road, Wuhan, Hubei, 430060, People's Republic of China
| | - Jing Chen
- Caidian District People's Hospital of Wuhan, Wuhan, Hubei, 430100, People's Republic of China
| | - Liping Chen
- Department of Obstetrics and Gynecology, Renmin Hospital of Wuhan University, 99 Zhang Zhidong Road, Wuhan, Hubei, 430060, People's Republic of China
| | - Hua Liu
- Department of Obstetrics and Gynecology, Renmin Hospital of Wuhan University, 99 Zhang Zhidong Road, Wuhan, Hubei, 430060, People's Republic of China.
| | - Yanxiang Cheng
- Department of Obstetrics and Gynecology, Renmin Hospital of Wuhan University, 99 Zhang Zhidong Road, Wuhan, Hubei, 430060, People's Republic of China.
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3
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Keller A, Bai H, Budinger S, Eliazer S, Hansen M, Konopka AR, Morales-Nebreda L, Najt CP, Prahlad V, Victorelli S, Vorland CJ, Yuan R, Rhoads TW, Mihaylova MM. The Third Annual Symposium of the Midwest Aging Consortium. J Gerontol A Biol Sci Med Sci 2024; 79:glad239. [PMID: 37804247 PMCID: PMC10799755 DOI: 10.1093/gerona/glad239] [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: 08/11/2023] [Indexed: 10/09/2023] Open
Abstract
The geroscience hypothesis suggests that addressing the fundamental mechanisms driving aging biology will prevent or mitigate the onset of multiple chronic diseases, for which the largest risk factor is advanced age. Research that investigates the root causes of aging is therefore of critical importance given the rising healthcare burden attributable to age-related diseases. The third annual Midwest Aging Consortium symposium was convened as a showcase of such research performed by investigators from institutions across the Midwestern United States. This report summarizes the work presented during a virtual conference across topics in aging biology, including immune function in the lung-particularly timely given the Corona Virus Immune Disease-2019 pandemic-along with the role of metabolism and nutrient-regulated pathways in cellular function with age, the influence of senescence on stem cell function and inflammation, and our evolving understanding of the mechanisms underlying observation of sex dimorphism in aging-related outcomes. The symposium focused on early-stage and emerging investigators, while including keynote presentations from leaders in the biology of aging field, highlighting the diversity and strength of aging research in the Midwest.
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Affiliation(s)
- Andrea Keller
- Department of Biological Chemistry and Pharmacology, College of Medicine, Ohio State University, Columbus, Ohio, USA
- Comprehensive Cancer Center, Wexner Medical Center, Arthur G. James Cancer Hospital, Ohio State University, Columbus, Ohio, USA
| | - Hua Bai
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, Iowa, USA
| | - Scott Budinger
- Division of Pulmonary and Critical Care Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Susan Eliazer
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota, USA
| | - Malene Hansen
- Buck Institute for Research on Aging, Novato, California, USA
| | - Adam R Konopka
- Division of Geriatrics and Gerontology, Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Geriatric Research, Education, and Clinical Center, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin, USA
| | - Luisa Morales-Nebreda
- Division of Pulmonary and Critical Care Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Charles P Najt
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - Veena Prahlad
- Department of Biology, Aging Mind and Brain Initiative; Iowa Neuroscience Institute, University of Iowa, Iowa City, Iowa, USA
- Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center, Buffalo, New York, USA
| | - Stella Victorelli
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
| | - Colby J Vorland
- Department of Epidemiology and Biostatistics, Indiana University School of Public Health-Bloomington, Bloomington, Indiana, USA
| | - Rong Yuan
- Geriatric Research Division, Department of Internal Medicine, Southern Illinois University School of Medicine, Springfield, Illinois, USA
| | - Timothy W Rhoads
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Maria M Mihaylova
- Department of Biological Chemistry and Pharmacology, College of Medicine, Ohio State University, Columbus, Ohio, USA
- Comprehensive Cancer Center, Wexner Medical Center, Arthur G. James Cancer Hospital, Ohio State University, Columbus, Ohio, USA
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4
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Nambiar A, Manjithaya R. Driving autophagy - the role of molecular motors. J Cell Sci 2024; 137:jcs260481. [PMID: 38329417 DOI: 10.1242/jcs.260481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2024] Open
Abstract
Most of the vesicular transport pathways inside the cell are facilitated by molecular motors that move along cytoskeletal networks. Autophagy is a well-explored catabolic pathway that is initiated by the formation of an isolation membrane known as the phagophore, which expands to form a double-membraned structure that captures its cargo and eventually moves towards the lysosomes for fusion. Molecular motors and cytoskeletal elements have been suggested to participate at different stages of the process as the autophagic vesicles move along cytoskeletal tracks. Dynein and kinesins govern autophagosome trafficking on microtubules through the sequential recruitment of their effector proteins, post-translational modifications and interactions with LC3-interacting regions (LIRs). In contrast, myosins are actin-based motors that participate in various stages of the autophagic flux, as well as in selective autophagy pathways. However, several outstanding questions remain with regard to how the dominance of a particular motor protein over another is controlled, and to the molecular mechanisms that underlie specific disease variants in motor proteins. In this Review, we aim to provide an overview of the role of molecular motors in autophagic flux, as well as highlight their dysregulation in diseases, such as neurodegenerative disorders and pathogenic infections, and ageing.
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Affiliation(s)
- Akshaya Nambiar
- Autophagy Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064, India
| | - Ravi Manjithaya
- Autophagy Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064, India
- Neuroscience Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064, India
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5
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Liénard C, Pintart A, Bomont P. Neuronal Autophagy: Regulations and Implications in Health and Disease. Cells 2024; 13:103. [PMID: 38201307 PMCID: PMC10778363 DOI: 10.3390/cells13010103] [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: 10/26/2023] [Revised: 12/02/2023] [Accepted: 12/27/2023] [Indexed: 01/12/2024] Open
Abstract
Autophagy is a major degradative pathway that plays a key role in sustaining cell homeostasis, integrity, and physiological functions. Macroautophagy, which ensures the clearance of cytoplasmic components engulfed in a double-membrane autophagosome that fuses with lysosomes, is orchestrated by a complex cascade of events. Autophagy has a particularly strong impact on the nervous system, and mutations in core components cause numerous neurological diseases. We first review the regulation of autophagy, from autophagosome biogenesis to lysosomal degradation and associated neurodevelopmental/neurodegenerative disorders. We then describe how this process is specifically regulated in the axon and in the somatodendritic compartment and how it is altered in diseases. In particular, we present the neuronal specificities of autophagy, with the spatial control of autophagosome biogenesis, the close relationship of maturation with axonal transport, and the regulation by synaptic activity. Finally, we discuss the physiological functions of autophagy in the nervous system, during development and in adulthood.
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Affiliation(s)
- Caroline Liénard
- NeuroMyoGene Institute—PGNM, CNRS UMR 5261—INSERM U1315, University of Claude Bernard Lyon 1, 69008 Lyon, France; (C.L.); (A.P.)
- CHU Montpellier, University of Montpellier, 34295 Montpellier, France
| | - Alexandre Pintart
- NeuroMyoGene Institute—PGNM, CNRS UMR 5261—INSERM U1315, University of Claude Bernard Lyon 1, 69008 Lyon, France; (C.L.); (A.P.)
| | - Pascale Bomont
- NeuroMyoGene Institute—PGNM, CNRS UMR 5261—INSERM U1315, University of Claude Bernard Lyon 1, 69008 Lyon, France; (C.L.); (A.P.)
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Schreiber A. A non-canonical role: The Hippo pathway regulator MAP4K2 controls autophagy and cell survival upon energy stress. Mol Cell 2023; 83:3043-3045. [PMID: 37683608 DOI: 10.1016/j.molcel.2023.08.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 08/11/2023] [Accepted: 08/11/2023] [Indexed: 09/10/2023]
Abstract
In this issue, Seo et al.1 report a non-canonical function of the Hippo kinase MAP4K2 in energy stress response by regulating autophagy and cell survival, with relevance and therapeutic potential for head and neck cancer treatment.
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Affiliation(s)
- Anne Schreiber
- Cellular Degradation Systems Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK.
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Seo G, Yu C, Han H, Xing L, Kattan RE, An J, Kizhedathu A, Yang B, Luo A, Buckle AL, Tifrea D, Edwards R, Huang L, Ju HQ, Wang W. The Hippo pathway noncanonically drives autophagy and cell survival in response to energy stress. Mol Cell 2023; 83:3155-3170.e8. [PMID: 37595580 PMCID: PMC10568779 DOI: 10.1016/j.molcel.2023.07.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 06/22/2023] [Accepted: 07/18/2023] [Indexed: 08/20/2023]
Abstract
The Hippo pathway is known for its crucial involvement in development, regeneration, organ size control, and cancer. While energy stress is known to activate the Hippo pathway and inhibit its effector YAP, the precise role of the Hippo pathway in energy stress response remains unclear. Here, we report a YAP-independent function of the Hippo pathway in facilitating autophagy and cell survival in response to energy stress, a process mediated by its upstream components MAP4K2 and STRIPAK. Mechanistically, energy stress disrupts the MAP4K2-STRIPAK association, leading to the activation of MAP4K2. Subsequently, MAP4K2 phosphorylates ATG8-family member LC3, thereby facilitating autophagic flux. MAP4K2 is highly expressed in head and neck cancer, and its mediated autophagy is required for head and neck tumor growth in mice. Altogether, our study unveils a noncanonical role of the Hippo pathway in energy stress response, shedding light on this key growth-related pathway in tissue homeostasis and cancer.
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Affiliation(s)
- Gayoung Seo
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA 92697, USA
| | - Clinton Yu
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA 92697, USA
| | - Han Han
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA 92697, USA
| | - Li Xing
- Irvine Materials Research Institute, University of California, Irvine, Irvine, CA 92697, USA
| | - Rebecca Elizabeth Kattan
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA 92697, USA
| | - Jeongmin An
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA 92697, USA
| | - Amrutha Kizhedathu
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA 92697, USA
| | - Bing Yang
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA 92697, USA
| | - Annabella Luo
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA 92697, USA
| | - Abigail L Buckle
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA 92697, USA
| | - Delia Tifrea
- Department of Pathology, University of California, Irvine, Irvine, CA 92697, USA
| | - Robert Edwards
- Department of Pathology, University of California, Irvine, Irvine, CA 92697, USA
| | - Lan Huang
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA 92697, USA
| | - Huai-Qiang Ju
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou 510060, China.
| | - Wenqi Wang
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA 92697, USA.
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8
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Ullah MI, Rehman Z, Dad R, Alsrhani A, Shakil M, Ghanem HB, Alameen AAM, Elsadek MF, Eltayeb LB, Ullah S, Atif M. Identification and Functional Characterization of Mutation in FYCO1 in Families with Congenital Cataract. Life (Basel) 2023; 13:1788. [PMID: 37629644 PMCID: PMC10456301 DOI: 10.3390/life13081788] [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: 07/18/2023] [Revised: 08/10/2023] [Accepted: 08/18/2023] [Indexed: 08/27/2023] Open
Abstract
Congenital cataract (CC) causes a third of the cases of treatable childhood blindness worldwide. CC is a disorder of the crystalline lens which is established as clinically divergent and has complex heterogeneity. This study aimed to determine the genetic basis of CC. Whole blood was obtained from four consanguineous families with CC. Genomic DNA was extracted from the blood, and the combination of targeted and Sanger sequencing was used to identify the causative gene. The mutations detected were analyzed in silico for structural and protein-protein interactions to predict their impact on protein activities. The sequencing found a known FYCO1 mutation (c.2206C>T; p.Gln736Term) in autosomal recessive mode in families with CC. Co-segregation analysis showed affected individuals as homozygous and carriers as heterozygous for the mutation and the unaffected as wild-type. Bioinformatics tools uncovered the loss of the Znf domain and structural compactness of the mutant protein. In conclusion, a previously reported nonsense mutation was identified in four consanguineous families with CC. Structural analysis predicted the protein as disordered and coordinated with other structural proteins. The autophagy process was found to be significant for the development of the lens and maintenance of its transparency. The identification of these markers expands the scientific knowledge of CC; the future goal should be to understand the mechanism of disease severity. Ascertaining the genetic etiology of CC in a family member facilitates establishing a molecular diagnosis, unlocks the prospect of prenatal diagnosis in pregnancies, and guides the successive generations by genetic counseling.
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Affiliation(s)
- Muhammad Ikram Ullah
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Jouf University, Sakaka 72388, Saudi Arabia; (A.A.); (H.B.G.); (A.A.M.A.); (M.A.)
| | - Zaira Rehman
- Department of Pathology, Indus Hospital & Health Network, Karachi 75190, Pakistan;
| | - Rubina Dad
- Structure Biology Research Centre, Human Technopole, 20157 Milan, Italy
| | - Abdullah Alsrhani
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Jouf University, Sakaka 72388, Saudi Arabia; (A.A.); (H.B.G.); (A.A.M.A.); (M.A.)
| | - Muhammad Shakil
- Department of Biochemistry, King Edward Medical University, Lahore 54600, Pakistan;
- Department of Biochemistry, University of Health Sciences, Lahore 54600, Pakistan
| | - Heba Bassiony Ghanem
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Jouf University, Sakaka 72388, Saudi Arabia; (A.A.); (H.B.G.); (A.A.M.A.); (M.A.)
| | - Ayman Ali Mohammed Alameen
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Jouf University, Sakaka 72388, Saudi Arabia; (A.A.); (H.B.G.); (A.A.M.A.); (M.A.)
| | - Mohamed Farouk Elsadek
- Department of Community Health Sciences, College of Applied Medical Sciences, King Saud University, Riyadh 11433, Saudi Arabia;
| | - Lienda Bashier Eltayeb
- Department of Medical Laboratory Sciences, College of Applied Medical Sciences, Prince Sattam Bin Abdul-Aziz University, Al-Kharj, Riyadh 11942, Saudi Arabia;
| | - Sajjad Ullah
- University Institute of Medical Laboratory Technology, Faculty of Allied Health Sciences, The University of Lahore, Lahore 54600, Pakistan;
| | - Muhammad Atif
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Jouf University, Sakaka 72388, Saudi Arabia; (A.A.); (H.B.G.); (A.A.M.A.); (M.A.)
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9
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Nieto-Torres JL, Zaretski S, Liu T, Adams PD, Hansen M. Post-translational modifications of ATG8 proteins - an emerging mechanism of autophagy control. J Cell Sci 2023; 136:jcs259725. [PMID: 37589340 PMCID: PMC10445744 DOI: 10.1242/jcs.259725] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/18/2023] Open
Abstract
Autophagy is a recycling mechanism involved in cellular homeostasis with key implications for health and disease. The conjugation of the ATG8 family proteins, which includes LC3B (also known as MAP1LC3B), to autophagosome membranes, constitutes a hallmark of the canonical autophagy process. After ATG8 proteins are conjugated to the autophagosome membranes via lipidation, they orchestrate a plethora of protein-protein interactions that support key steps of the autophagy process. These include binding to cargo receptors to allow cargo recruitment, association with proteins implicated in autophagosome transport and autophagosome-lysosome fusion. How these diverse and critical protein-protein interactions are regulated is still not well understood. Recent reports have highlighted crucial roles for post-translational modifications of ATG8 proteins in the regulation of ATG8 functions and the autophagy process. This Review summarizes the main post-translational regulatory events discovered to date to influence the autophagy process, mostly described in mammalian cells, including ubiquitylation, acetylation, lipidation and phosphorylation, as well as their known contributions to the autophagy process, physiology and disease.
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Affiliation(s)
- Jose L. Nieto-Torres
- Sanford Burnham Prebys Medical Discovery Institute, Program of Development, Aging, and Regeneration, La Jolla, CA 92037, USA
- Department of Biomedical Sciences, School of Health Sciences and Veterinary, Universidad Cardenal Herrera-CEU, CEU Universities, 46113 Moncada, Spain
| | - Sviatlana Zaretski
- Sanford Burnham Prebys Medical Discovery Institute, Program of Development, Aging, and Regeneration, La Jolla, CA 92037, USA
| | - Tianhui Liu
- Sanford Burnham Prebys Medical Discovery Institute, Program of Development, Aging, and Regeneration, La Jolla, CA 92037, USA
| | - Peter D. Adams
- Sanford Burnham Prebys Medical Discovery Institute, Program of Development, Aging, and Regeneration, La Jolla, CA 92037, USA
| | - Malene Hansen
- Sanford Burnham Prebys Medical Discovery Institute, Program of Development, Aging, and Regeneration, La Jolla, CA 92037, USA
- The Buck Institute for Aging Research, Novato, CA 94945, USA
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10
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Sellung D, Heil L, Daya N, Jacobsen F, Mertens-Rill J, Zhuge H, Döring K, Piran M, Milting H, Unger A, Linke WA, Kley R, Preusse C, Roos A, Fürst DO, Ven PFMVD, Vorgerd M. Novel Filamin C Myofibrillar Myopathy Variants Cause Different Pathomechanisms and Alterations in Protein Quality Systems. Cells 2023; 12:cells12091321. [PMID: 37174721 PMCID: PMC10177260 DOI: 10.3390/cells12091321] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 04/28/2023] [Accepted: 05/03/2023] [Indexed: 05/15/2023] Open
Abstract
Myofibrillar myopathies (MFM) are a group of chronic muscle diseases pathophysiologically characterized by accumulation of protein aggregates and structural failure of muscle fibers. A subtype of MFM is caused by heterozygous mutations in the filamin C (FLNC) gene, exhibiting progressive muscle weakness, muscle structural alterations and intracellular protein accumulations. Here, we characterize in depth the pathogenicity of two novel truncating FLNc variants (p.Q1662X and p.Y2704X) and assess their distinct effect on FLNc stability and distribution as well as their impact on protein quality system (PQS) pathways. Both variants cause a slowly progressive myopathy with disease onset in adulthood, chronic myopathic alterations in muscle biopsy including the presence of intracellular protein aggregates. Our analyses revealed that p.Q1662X results in FLNc haploinsufficiency and p.Y2704X in a dominant-negative FLNc accumulation. Moreover, both protein-truncating variants cause different PQS alterations: p.Q1662X leads to an increase in expression of several genes involved in the ubiquitin-proteasome system (UPS) and the chaperone-assisted selective autophagy (CASA) system, whereas p.Y2704X results in increased abundance of proteins involved in UPS activation and autophagic buildup. We conclude that truncating FLNC variants might have different pathogenetic consequences and impair PQS function by diverse mechanisms and to varying extents. Further studies on a larger number of patients are necessary to confirm our observations.
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Affiliation(s)
- Dominik Sellung
- Department of Neurology, Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, 44789 Bochum, Germany
| | - Lorena Heil
- Department of Molecular Cell Biology, Institute for Cell Biology, University of Bonn, 53121 Bonn, Germany
| | - Nassam Daya
- Department of Neurology, Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, 44789 Bochum, Germany
| | - Frank Jacobsen
- Department of Neurology, Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, 44789 Bochum, Germany
| | - Janine Mertens-Rill
- Department of Neurology, Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, 44789 Bochum, Germany
| | - Heidi Zhuge
- Department of Neurology, Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, 44789 Bochum, Germany
| | - Kristina Döring
- Department of Human Genetics, Ruhr-University Bochum, 44801 Bochum, Germany
| | - Misagh Piran
- Erich and Hanna Klessmann Institute, Heart and Diabetes Centre NRW, University Hospital of the Ruhr-University Bochum, 32545 Bad Oeynhausen, Germany
| | - Hendrik Milting
- Erich and Hanna Klessmann Institute, Heart and Diabetes Centre NRW, University Hospital of the Ruhr-University Bochum, 32545 Bad Oeynhausen, Germany
| | - Andreas Unger
- Institute of Physiology II, University of Münster, 48149 Münster, Germany
| | - Wolfgang A Linke
- Institute of Physiology II, University of Münster, 48149 Münster, Germany
| | - Rudi Kley
- Department of Neurology and Clinical Neurophysiology, St. Marien-Hospital Borken, 46325 Borken, Germany
| | - Corinna Preusse
- Department of Neuropathology, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Andreas Roos
- Department of Neurology, Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, 44789 Bochum, Germany
| | - Dieter O Fürst
- Department of Molecular Cell Biology, Institute for Cell Biology, University of Bonn, 53121 Bonn, Germany
| | - Peter F M van der Ven
- Department of Molecular Cell Biology, Institute for Cell Biology, University of Bonn, 53121 Bonn, Germany
| | - Matthias Vorgerd
- Department of Neurology, Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, 44789 Bochum, Germany
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11
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Yin Y, Tan M, Han L, Zhang L, Zhang Y, Zhang J, Pan W, Bai J, Jiang T, Li H. The hippo kinases MST1/2 in cardiovascular and metabolic diseases: A promising therapeutic target option for pharmacotherapy. Acta Pharm Sin B 2023; 13:1956-1975. [PMID: 37250161 PMCID: PMC10213817 DOI: 10.1016/j.apsb.2023.01.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 09/09/2022] [Accepted: 11/18/2022] [Indexed: 02/05/2023] Open
Abstract
Cardiovascular diseases (CVDs) and metabolic disorders are major components of noncommunicable diseases, causing an enormous health and economic burden worldwide. There are common risk factors and developmental mechanisms among them, indicating the far-reaching significance in exploring the corresponding therapeutic targets. MST1/2 kinases are well-established proapoptotic effectors that also bidirectionally regulate autophagic activity. Recent studies have demonstrated that MST1/2 influence the outcome of cardiovascular and metabolic diseases by regulating immune inflammation. In addition, drug development against them is in full swing. In this review, we mainly describe the roles and mechanisms of MST1/2 in apoptosis and autophagy in cardiovascular and metabolic events as well as emphasis on the existing evidence for their involvement in immune inflammation. Moreover, we summarize the latest progress of pharmacotherapy targeting MST1/2 and propose a new mode of drug combination therapy, which may be beneficial to seek more effective strategies to prevent and treat CVDs and metabolic disorders.
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Affiliation(s)
- Yunfei Yin
- Department of Cardiology, the First Affiliated Hospital of Soochow University, Suzhou 215006, China
| | - Mingyue Tan
- Department of Cardiology, the First Affiliated Hospital of Soochow University, Suzhou 215006, China
| | - Lianhua Han
- Department of Cardiology, the First Affiliated Hospital of Soochow University, Suzhou 215006, China
| | - Lei Zhang
- Department of Cardiology, the First Affiliated Hospital of Soochow University, Suzhou 215006, China
| | - Yue Zhang
- Department of Cardiology, the First Affiliated Hospital of Soochow University, Suzhou 215006, China
| | - Jun Zhang
- Department of Cardiology, the First Affiliated Hospital of Soochow University, Suzhou 215006, China
| | - Wanqian Pan
- Department of Cardiology, the First Affiliated Hospital of Soochow University, Suzhou 215006, China
| | - Jiaxiang Bai
- Department of Cardiology, the First Affiliated Hospital of Soochow University, Suzhou 215006, China
- Department of Orthopedics, the First Affiliated Hospital of Soochow University, Suzhou 215006, China
- Department of Orthopedics, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230001, China
| | - Tingbo Jiang
- Department of Cardiology, the First Affiliated Hospital of Soochow University, Suzhou 215006, China
| | - Hongxia Li
- Department of Cardiology, the First Affiliated Hospital of Soochow University, Suzhou 215006, China
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12
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Brennan L, Costello MJ, Hejtmancik JF, Menko AS, Riazuddin SA, Shiels A, Kantorow M. Autophagy Requirements for Eye Lens Differentiation and Transparency. Cells 2023; 12:475. [PMID: 36766820 PMCID: PMC9914699 DOI: 10.3390/cells12030475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/17/2023] [Accepted: 01/25/2023] [Indexed: 02/05/2023] Open
Abstract
Recent evidence points to autophagy as an essential cellular requirement for achieving the mature structure, homeostasis, and transparency of the lens. Collective evidence from multiple laboratories using chick, mouse, primate, and human model systems provides evidence that classic autophagy structures, ranging from double-membrane autophagosomes to single-membrane autolysosomes, are found throughout the lens in both undifferentiated lens epithelial cells and maturing lens fiber cells. Recently, key autophagy signaling pathways have been identified to initiate critical steps in the lens differentiation program, including the elimination of organelles to form the core lens organelle-free zone. Other recent studies using ex vivo lens culture demonstrate that the low oxygen environment of the lens drives HIF1a-induced autophagy via upregulation of essential mitophagy components to direct the specific elimination of the mitochondria, endoplasmic reticulum, and Golgi apparatus during lens fiber cell differentiation. Pioneering studies on the structural requirements for the elimination of nuclei during lens differentiation reveal the presence of an entirely novel structure associated with degrading lens nuclei termed the nuclear excisosome. Considerable evidence also indicates that autophagy is a requirement for lens homeostasis, differentiation, and transparency, since the mutation of key autophagy proteins results in human cataract formation.
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Affiliation(s)
- Lisa Brennan
- Department of Biomedical Science, Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL 33460, USA
| | - M. Joseph Costello
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - J. Fielding Hejtmancik
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - A. Sue Menko
- Department of Pathology, Anatomy and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
- Department of Ophthalmology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - S. Amer Riazuddin
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Alan Shiels
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Marc Kantorow
- Department of Biomedical Science, Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL 33460, USA
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13
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Maejima Y, Zablocki D, Nah J, Sadoshima J. The role of the Hippo pathway in autophagy in the heart. Cardiovasc Res 2023; 118:3320-3330. [PMID: 35150237 DOI: 10.1093/cvr/cvac014] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Accepted: 02/07/2022] [Indexed: 01/25/2023] Open
Abstract
The Hippo pathway, an evolutionarily conserved signalling mechanism, controls organ size and tumourigenesis. Increasing lines of evidence suggest that autophagy, an important mechanism of lysosome-mediated cellular degradation, is regulated by the Hippo pathway, which thereby profoundly affects cell growth and death responses in various cell types. In the heart, Mst1, an upstream component of the Hippo pathway, not only induces apoptosis but also inhibits autophagy through phosphorylation of Beclin 1. YAP/TAZ, transcription factor co-factors and the terminal effectors of the Hippo pathway, affect autophagy through transcriptional activation of TFEB, a master regulator of autophagy and lysosomal biogenesis. The cellular abundance of YAP is negatively regulated by autophagy and suppression of autophagy induces accumulation of YAP, which, in turn, acts as a feedback mechanism to induce autophagosome formation. Thus, the Hippo pathway and autophagy regulate each other, thereby profoundly affecting cardiomyocyte survival and death. This review discusses the interaction between the Hippo pathway and autophagy and its functional significance during stress conditions in the heart and the cardiomyocytes therein.
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Affiliation(s)
- Yasuhiro Maejima
- Department of Cell Biology and Molecular Medicine, Cardiovascular Research Institute, Rutgers-New Jersey Medical School, 185 South Orange Ave., MSB G-609, Newark, NJ 07103, USA.,Department of Cardiovascular Medicine, Tokyo Medical and Dental University, Tokyo 113-8510, Japan
| | - Daniela Zablocki
- Department of Cell Biology and Molecular Medicine, Cardiovascular Research Institute, Rutgers-New Jersey Medical School, 185 South Orange Ave., MSB G-609, Newark, NJ 07103, USA
| | - Jihoon Nah
- School of Biological Sciences, Seoul National University, Seoul 08826, Korea
| | - Junichi Sadoshima
- Department of Cell Biology and Molecular Medicine, Cardiovascular Research Institute, Rutgers-New Jersey Medical School, 185 South Orange Ave., MSB G-609, Newark, NJ 07103, USA
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14
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Kumar AV, Mills J. Non-canonical autophagy in aging and age-related diseases. Front Cell Dev Biol 2023; 11:1137870. [PMID: 36910139 PMCID: PMC9995962 DOI: 10.3389/fcell.2023.1137870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 02/13/2023] [Indexed: 02/25/2023] Open
Abstract
Autophagy, one of the arms of proteostasis, influences aging and age-related diseases. Recently, the discovery of additional roles of autophagy-related proteins in non-canonical degradation and secretion has revealed alternative fates of autophagic cargo. Some of these non-canonical pathways have been linked to neurodegenerative diseases and improving the understanding of this link is crucial for their potential targetability in aging and age-related diseases. This review discusses recent investigations of the involvement of non-canonical autophagy players and pathways in age-related diseases that are now beginning to be discovered. Unraveling these pathways and their relation to classical autophagy could unearth a fascinating new layer of proteostasis regulation during normal aging and in longevity.
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Affiliation(s)
- Anita V Kumar
- Molecular Biology, Cell Biology and Biochemistry Department, Brown University, Providence, RI, United States
| | - Joslyn Mills
- Molecular Biology, Cell Biology and Biochemistry Department, Brown University, Providence, RI, United States.,Wheaton College, Biology Department, Norton, MA, United States
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15
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Reid SE, Kolapalli SP, Nielsen TM, Frankel LB. Canonical and non-canonical roles for ATG8 proteins in autophagy and beyond. Front Mol Biosci 2022; 9:1074701. [PMID: 36601581 PMCID: PMC9806848 DOI: 10.3389/fmolb.2022.1074701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 11/29/2022] [Indexed: 12/23/2022] Open
Abstract
During autophagy, the ATG8 family proteins have several well-characterized roles in facilitating early, mid, and late steps of autophagy, including autophagosome expansion, cargo recruitment and autophagosome-lysosome fusion. Their discovery has importantly allowed for precise experimental monitoring of the pathway, bringing about a huge expansion of research in the field over the last decades. In this review, we discuss both canonical and non-canonical roles of the autophagic lipidation machinery, with particular focus on the ATG8 proteins, their post-translational modifications and their increasingly uncovered alternative roles mediated through their anchoring at different membranes. These include endosomes, macropinosomes, phagosomes and the plasma membrane, to which ATG8 proteins can bind through canonical or alternative lipidation. Beyond new ATG8 binding partners and cargo types, we also explore several open questions related to alternative outcomes of autophagic machinery engagement beyond degradation. These include their roles in plasma membrane repair and secretion of selected substrates as well as the physiological implications hereof in health and disease.
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Affiliation(s)
| | | | | | - Lisa B. Frankel
- Danish Cancer Society Research Center, Copenhagen, Denmark,Biotech Research and Innovation Center, University of Copenhagen, Copenhagen, Denmark,*Correspondence: Lisa B. Frankel,
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16
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Cui L, Li H, Xi Y, Hu Q, Liu H, Fan J, Xiang Y, Zhang X, Shui W, Lai Y. Vesicle trafficking and vesicle fusion: mechanisms, biological functions, and their implications for potential disease therapy. MOLECULAR BIOMEDICINE 2022; 3:29. [PMID: 36129576 PMCID: PMC9492833 DOI: 10.1186/s43556-022-00090-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 07/12/2022] [Indexed: 11/10/2022] Open
Abstract
Intracellular vesicle trafficking is the fundamental process to maintain the homeostasis of membrane-enclosed organelles in eukaryotic cells. These organelles transport cargo from the donor membrane to the target membrane through the cargo containing vesicles. Vesicle trafficking pathway includes vesicle formation from the donor membrane, vesicle transport, and vesicle fusion with the target membrane. Coat protein mediated vesicle formation is a delicate membrane budding process for cargo molecules selection and package into vesicle carriers. Vesicle transport is a dynamic and specific process for the cargo containing vesicles translocation from the donor membrane to the target membrane. This process requires a group of conserved proteins such as Rab GTPases, motor adaptors, and motor proteins to ensure vesicle transport along cytoskeletal track. Soluble N-ethyl-maleimide-sensitive factor (NSF) attachment protein receptors (SNARE)-mediated vesicle fusion is the final process for vesicle unloading the cargo molecules at the target membrane. To ensure vesicle fusion occurring at a defined position and time pattern in eukaryotic cell, multiple fusogenic proteins, such as synaptotagmin (Syt), complexin (Cpx), Munc13, Munc18 and other tethering factors, cooperate together to precisely regulate the process of vesicle fusion. Dysfunctions of the fusogenic proteins in SNARE-mediated vesicle fusion are closely related to many diseases. Recent studies have suggested that stimulated membrane fusion can be manipulated pharmacologically via disruption the interface between the SNARE complex and Ca2+ sensor protein. Here, we summarize recent insights into the molecular mechanisms of vesicle trafficking, and implications for the development of new therapeutics based on the manipulation of vesicle fusion.
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17
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Distinct evolutionary trajectories of SARS-CoV-2-interacting proteins in bats and primates identify important host determinants of COVID-19. Proc Natl Acad Sci U S A 2022; 119:e2206610119. [PMID: 35947637 PMCID: PMC9436378 DOI: 10.1073/pnas.2206610119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
The coronavirus disease 19 (COVID-19) pandemic is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a coronavirus that spilled over from the bat reservoir. However, the host genetic determinants that drive SARS-CoV-2 susceptibility and COVID-19 severity are largely unknown. Understanding how cellular proteins interacting with SARS-CoV-2 have evolved in primates and bats is of primary importance to decipher differences in the infection outcome between humans and the viral reservoir in bats. Here, we performed comparative functional genetic analyses of hundreds of SARS-CoV-2-interacting proteins to study virus–host interface adaptation over millions of years, pointing to genes similarly—or differentially—engaged in evolutionary arms races and that may be at the basis of in vivo pathogenic differences. The coronavirus disease 19 (COVID-19) pandemic is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a coronavirus that spilled over from the bat reservoir. Despite numerous clinical trials and vaccines, the burden remains immense, and the host determinants of SARS-CoV-2 susceptibility and COVID-19 severity remain largely unknown. Signatures of positive selection detected by comparative functional genetic analyses in primate and bat genomes can uncover important and specific adaptations that occurred at virus–host interfaces. We performed high-throughput evolutionary analyses of 334 SARS-CoV-2-interacting proteins to identify SARS-CoV adaptive loci and uncover functional differences between modern humans, primates, and bats. Using DGINN (Detection of Genetic INNovation), we identified 38 bat and 81 primate proteins with marks of positive selection. Seventeen genes, including the ACE2 receptor, present adaptive marks in both mammalian orders, suggesting common virus–host interfaces and past epidemics of coronaviruses shaping their genomes. Yet, 84 genes presented distinct adaptations in bats and primates. Notably, residues involved in ubiquitination and phosphorylation of the inflammatory RIPK1 have rapidly evolved in bats but not primates, suggesting different inflammation regulation versus humans. Furthermore, we discovered residues with typical virus–host arms race marks in primates, such as in the entry factor TMPRSS2 or the autophagy adaptor FYCO1, pointing to host-specific in vivo interfaces that may be drug targets. Finally, we found that FYCO1 sites under adaptation in primates are those associated with severe COVID-19, supporting their importance in pathogenesis and replication. Overall, we identified adaptations involved in SARS-CoV-2 infection in bats and primates, enlightening modern genetic determinants of virus susceptibility and severity.
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18
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1-L Transcription in Alzheimer's Disease. Curr Issues Mol Biol 2022; 44:3533-3551. [PMID: 36005139 PMCID: PMC9406503 DOI: 10.3390/cimb44080243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 08/04/2022] [Accepted: 08/06/2022] [Indexed: 11/23/2022] Open
Abstract
Alzheimer’s disease is a very complex disease and better explanations and models are needed to understand how neurons are affected and microglia are activated. A new model of Alzheimer’s disease is presented here, the β-amyloid peptide is considered an important RNA recognition/binding peptide. 1-L transcription revealed compatible sequences with AAUAAA (PAS signal) and UUUC (class III ARE rich in U) in the Aβ peptide, supporting the peptide–RNA regulatory model. When a hypothetical model of fibril selection with the prionic character of amyloid assemblies is added to the peptide-RNA regulatory model, the downregulation of the PI3K-Akt pathway and the upregulation of the PLC-IP3 pathway are well explained. The model explains why neurons are less protected from inflammation and why microglia are activated; why mitochondria are destabilized; why the autophagic flux is destabilized; and why the post-transcriptional attenuation of the axonal signal “noise” is interrupted. For example, the model suggests that Aβ peptide may post-transcriptionally control ELAVL2 (ELAV-like RNA binding protein 2) and DCP2 (decapping mRNA protein 2), which are known to regulate RNA processing, transport, and stability.
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19
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Sidibe DK, Vogel MC, Maday S. Organization of the autophagy pathway in neurons. Curr Opin Neurobiol 2022; 75:102554. [PMID: 35649324 PMCID: PMC9990471 DOI: 10.1016/j.conb.2022.102554] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 03/28/2022] [Accepted: 04/12/2022] [Indexed: 01/18/2023]
Abstract
Macroautophagy (hereafter referred to as autophagy) is an essential quality-control pathway in neurons, which face unique functional and morphological challenges in maintaining the integrity of organelles and the proteome. To overcome these challenges, neurons have developed compartment-specific pathways for autophagy. In this review, we discuss the organization of the autophagy pathway, from autophagosome biogenesis, trafficking, to clearance, in the neuron. We dissect the compartment-specific mechanisms and functions of autophagy in axons, dendrites, and the soma. Furthermore, we highlight examples of how steps along the autophagy pathway are impaired in the context of aging and neurodegenerative disease, which underscore the critical importance of autophagy in maintaining neuronal function and survival.
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Affiliation(s)
- David K Sidibe
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Maria C Vogel
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Sandra Maday
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104, USA.
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20
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Almacellas E, Mauvezin C. Emerging roles of mitotic autophagy. J Cell Sci 2022; 135:275665. [PMID: 35686549 DOI: 10.1242/jcs.255802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Lysosomes exert pleiotropic functions to maintain cellular homeostasis and degrade autophagy cargo. Despite the great advances that have boosted our understanding of autophagy and lysosomes in both physiology and pathology, their function in mitosis is still controversial. During mitosis, most organelles are reshaped or repurposed to allow the correct distribution of chromosomes. Mitotic entry is accompanied by a reduction in sites of autophagy initiation, supporting the idea of an inhibition of autophagy to protect the genetic material against harmful degradation. However, there is accumulating evidence revealing the requirement of selective autophagy and functional lysosomes for a faithful chromosome segregation. Degradation is the most-studied lysosomal activity, but recently described alternative functions that operate in mitosis highlight the lysosomes as guardians of mitotic progression. Because the involvement of autophagy in mitosis remains controversial, it is important to consider the specific contribution of signalling cascades, the functions of autophagic proteins and the multiple roles of lysosomes, as three entangled, but independent, factors controlling genomic stability. In this Review, we discuss the latest advances in this area and highlight the therapeutic potential of targeting autophagy for drug development.
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Affiliation(s)
- Eugenia Almacellas
- Molecular Cell Biology of Autophagy, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Caroline Mauvezin
- Department of Biomedicine, Faculty of Medicine, University of Barcelona c/ Casanova, 143 08036 Barcelona, Spain.,August Pi i Sunyer Biomedical Research Institute (IDIBAPS), c/ Rosselló, 149-153 08036 Barcelona, Spain
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21
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Cable J, Weber-Ban E, Clausen T, Walters KJ, Sharon M, Finley DJ, Gu Y, Hanna J, Feng Y, Martens S, Simonsen A, Hansen M, Zhang H, Goodwin JM, Reggio A, Chang C, Ge L, Schulman BA, Deshaies RJ, Dikic I, Harper JW, Wertz IE, Thomä NH, Słabicki M, Frydman J, Jakob U, David DC, Bennett EJ, Bertozzi CR, Sardana R, Eapen VV, Carra S. Targeted protein degradation: from small molecules to complex organelles-a Keystone Symposia report. Ann N Y Acad Sci 2022; 1510:79-99. [PMID: 35000205 DOI: 10.1111/nyas.14745] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 12/10/2021] [Indexed: 12/15/2022]
Abstract
Targeted protein degradation is critical for proper cellular function and development. Protein degradation pathways, such as the ubiquitin proteasomes system, autophagy, and endosome-lysosome pathway, must be tightly regulated to ensure proper elimination of misfolded and aggregated proteins and regulate changing protein levels during cellular differentiation, while ensuring that normal proteins remain unscathed. Protein degradation pathways have also garnered interest as a means to selectively eliminate target proteins that may be difficult to inhibit via other mechanisms. On June 7 and 8, 2021, several experts in protein degradation pathways met virtually for the Keystone eSymposium "Targeting protein degradation: from small molecules to complex organelles." The event brought together researchers working in different protein degradation pathways in an effort to begin to develop a holistic, integrated vision of protein degradation that incorporates all the major pathways to understand how changes in them can lead to disease pathology and, alternatively, how they can be leveraged for novel therapeutics.
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Affiliation(s)
| | - Eilika Weber-Ban
- Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland
| | - Tim Clausen
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter and Medical University of Vienna, Vienna, Austria
| | - Kylie J Walters
- Protein Processing Section, Center for Structural Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland
| | - Michal Sharon
- Department of Bimolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Daniel J Finley
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts
| | - Yangnan Gu
- Department of Plant and Microbial Biology and Innovative Genomics Institute, University of California, Berkeley, California
| | - John Hanna
- Department of Pathology, Harvard Medical School and Brigham and Women's Hospital, Boston, Massachusetts
| | - Yue Feng
- Princess Margaret Cancer Centre, University Health Network and Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - Sascha Martens
- Max Perutz Labs, University of Vienna, Vienna BioCenter (VBC), Vienna, Austria
| | - Anne Simonsen
- Department of Molecular Medicine, Institute of Basic Medical Sciences and Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, University of Oslo, Oslo, Norway
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Malene Hansen
- Sanford Burnham Prebys Medical Discovery Institute, Program of Development, Aging, and Regeneration, La Jolla, California
| | - Hong Zhang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences and College of Life Sciences, University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | | | - Alessio Reggio
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Chunmei Chang
- Molecular and Cell Biology, University of California, Berkeley, Berkeley, California
| | - Liang Ge
- State Key Laboratory of Membrane Biology, Tsinghua University-Peking University Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Brenda A Schulman
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
| | | | - Ivan Dikic
- Institute of Biochemistry II, School of Medicine and Buchmann Institute for Molecular Life Sciences, Goethe University, Frankfurt, Germany
| | - J Wade Harper
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts
| | - Ingrid E Wertz
- Departments of Molecular Oncology and Early Discovery Biochemistry, Genentech, Inc., South San Francisco, California
- Bristol Myers Squibb, Brisbane, California
| | - Nicolas H Thomä
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Mikołaj Słabicki
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts
- Division of Translational Medical Oncology, German Cancer Research Center (DKFZ) and National Center for Tumor Diseases (NCT), Heidelberg, Germany
| | - Judith Frydman
- Biophysics Graduate Program, Department of Biology and Department of Genetics, Stanford University, Stanford, California
- Biohub, San Francisco, California
- Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Menlo Park, California
| | - Ursula Jakob
- Department of Molecular, Cellular and Developmental Biology, College of Literature, Science, and the Arts, University of Michigan, Ann Arbor, Michigan
| | - Della C David
- German Center for Neurodegenerative Diseases (DZNE), and Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany
| | - Eric J Bennett
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California
| | - Carolyn R Bertozzi
- Department of Chemistry and Stanford ChEM-H, Stanford University and Howard Hughes Medical Institute, Stanford, California
| | - Richa Sardana
- Weill Institute of Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York
| | - Vinay V Eapen
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts
| | - Serena Carra
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
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22
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Collier JJ, Suomi F, Oláhová M, McWilliams TG, Taylor RW. Emerging roles of ATG7 in human health and disease. EMBO Mol Med 2021; 13:e14824. [PMID: 34725936 PMCID: PMC8649875 DOI: 10.15252/emmm.202114824] [Citation(s) in RCA: 66] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 09/08/2021] [Accepted: 09/13/2021] [Indexed: 12/12/2022] Open
Abstract
The cardinal stages of macroautophagy are driven by core autophagy-related (ATG) proteins, whose ablation largely abolishes intracellular turnover. Disrupting ATG genes is paradigmatic of studying autophagy deficiency, yet emerging data suggest that ATG proteins have extensive biological importance beyond autophagic elimination. An important example is ATG7, an essential autophagy effector enzyme that in concert with other ATG proteins, also regulates immunity, cell death and protein secretion, and independently regulates the cell cycle and apoptosis. Recently, a direct association between ATG7 dysfunction and disease was established in patients with biallelic ATG7 variants and childhood-onset neuropathology. Moreover, a prodigious body of evidence supports a role for ATG7 in protecting against complex disease states in model organisms, although how dysfunctional ATG7 contributes to manifestation of these diseases, including cancer, neurodegeneration and infection, in humans remains unclear. Here, we systematically review the biological functions of ATG7, discussing the impact of its impairment on signalling pathways and human pathology. Future studies illuminating the molecular relationship between ATG7 dysfunction and disease will expedite therapies for disorders involving ATG7 deficiency and/or impaired autophagy.
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Affiliation(s)
- Jack J Collier
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research InstituteNewcastle UniversityNewcastle upon TyneUK
- Present address:
Department of Neurology and NeurosurgeryMontreal Neurological InstituteMcGill UniversityMontrealQCCanada
| | - Fumi Suomi
- Translational Stem Cell Biology & Metabolism Program, Research Programs UnitUniversity of HelsinkiHelsinkiFinland
| | - Monika Oláhová
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research InstituteNewcastle UniversityNewcastle upon TyneUK
| | - Thomas G McWilliams
- Translational Stem Cell Biology & Metabolism Program, Research Programs UnitUniversity of HelsinkiHelsinkiFinland
- Department of AnatomyFaculty of MedicineUniversity of HelsinkiHelsinkiFinland
| | - Robert W Taylor
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research InstituteNewcastle UniversityNewcastle upon TyneUK
- NHS Highly Specialised Service for Rare Mitochondrial Disorders of Adults and ChildrenNewcastle UniversityNewcastle upon TyneUK
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23
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Nieto-Torres JL, Hansen M. Macroautophagy and aging: The impact of cellular recycling on health and longevity. Mol Aspects Med 2021; 82:101020. [PMID: 34507801 PMCID: PMC8671213 DOI: 10.1016/j.mam.2021.101020] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 08/11/2021] [Accepted: 08/31/2021] [Indexed: 02/08/2023]
Abstract
Aging is associated with many deleterious changes at the cellular level, including the accumulation of potentially toxic components that can have devastating effects on health. A key protective mechanism to this end is the cellular recycling process called autophagy. During autophagy, damaged or surplus cellular components are delivered to acidic vesicles called lysosomes, that secure degradation and recycling of the components. Numerous links between autophagy and aging exist. Autophagy declines with age, and increasing evidence suggests that this reduction plays important roles in both physiological aging and the development of age-associated disorders. Studies in pharmacologically and genetically manipulated model organisms indicate that defects in autophagy promote age-related diseases, and conversely, that enhancement of autophagy has beneficial effects on both healthspan and lifespan. Here, we review our current understanding of the role of autophagy in different physiological processes and their molecular links with aging and age-related diseases. We also highlight some recent advances in the field that could accelerate the development of autophagy-based therapeutic interventions.
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Affiliation(s)
- Jose L Nieto-Torres
- Sanford Burnham Prebys Medical Discovery Institute. Program of Development, Aging, and Regeneration, La Jolla, CA, USA
| | - Malene Hansen
- Sanford Burnham Prebys Medical Discovery Institute. Program of Development, Aging, and Regeneration, La Jolla, CA, USA.
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24
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Kaushik S, Tasset I, Arias E, Pampliega O, Wong E, Martinez-Vicente M, Cuervo AM. Autophagy and the hallmarks of aging. Ageing Res Rev 2021; 72:101468. [PMID: 34563704 DOI: 10.1016/j.arr.2021.101468] [Citation(s) in RCA: 93] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 09/12/2021] [Accepted: 09/20/2021] [Indexed: 12/13/2022]
Abstract
Autophagy, an essential cellular process that mediates degradation of proteins and organelles in lysosomes, has been tightly linked to cellular quality control for its role as part of the proteostasis network. The current interest in identifying the cellular and molecular determinants of aging, has highlighted the important contribution of malfunctioning of autophagy with age to the loss of proteostasis that characterizes all old organisms. However, the diversity of cellular functions of the different types of autophagy and the often reciprocal interactions of autophagy with other determinants of aging, is placing autophagy at the center of the aging process. In this work, we summarize evidence for the contribution of autophagy to health- and lifespan and provide examples of the bidirectional interplay between autophagic pathways and several of the so-called hallmarks of aging. This central role of autophagy in aging, and the dependence on autophagy of many geroprotective interventions, has motivated a search for direct modulators of autophagy that could be used to slow aging and extend healthspan. Here, we review some of those ongoing therapeutic efforts and comment on the potential of targeting autophagy in aging.
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25
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Guardia CM, Jain A, Mattera R, Friefeld A, Li Y, Bonifacino JS. RUSC2 and WDR47 oppositely regulate kinesin-1-dependent distribution of ATG9A to the cell periphery. Mol Biol Cell 2021; 32:ar25. [PMID: 34432492 PMCID: PMC8693955 DOI: 10.1091/mbc.e21-06-0295] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 08/10/2021] [Accepted: 08/18/2021] [Indexed: 01/12/2023] Open
Abstract
Autophagy-related protein 9 (ATG9) is a transmembrane protein component of the autophagy machinery that cycles between the trans-Golgi network (TGN) in the perinuclear area and other compartments in the peripheral area of the cell. In mammalian cells, export of the ATG9A isoform from the TGN into ATG9A-containing vesicles is mediated by the adaptor protein 4 (AP-4) complex. However, the mechanisms responsible for the subsequent distribution of these vesicles to the cell periphery are unclear. Herein we show that the AP-4-accessory protein RUSC2 couples ATG9A-containing vesicles to the plus-end-directed microtubule motor kinesin-1 via an interaction between a disordered region of RUSC2 and the kinesin-1 light chain. This interaction is counteracted by the microtubule-associated protein WDR47. These findings uncover a mechanism for the peripheral distribution of ATG9A-containing vesicles involving the function of RUSC2 as a kinesin-1 adaptor and WDR47 as a negative regulator of this function.
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Affiliation(s)
- Carlos M. Guardia
- Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development
| | - Akansha Jain
- Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development
| | - Rafael Mattera
- Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development
| | - Alex Friefeld
- Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development
| | - Yan Li
- Proteomics Core Facility, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892
| | - Juan S. Bonifacino
- Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development
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26
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Nieto-Torres JL, Durgan J, Franco-Romero A, Grumati P, Guardia CM, Leidal AM, Mandell MA, Towers CG, Wang F. The Autophagy, Inflammation and Metabolism Center international eSymposium - an early-career investigators' seminar series during the COVID-19 pandemic. J Cell Sci 2021; 134:jcs259268. [PMID: 34622922 PMCID: PMC8520733 DOI: 10.1242/jcs.259268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Autophagy, Inflammation and Metabolism (AIM) Center organized a globally accessible, virtual eSymposium during the COVID-19 pandemic in 2020. The conference included presentations from scientific leaders, as well as a career discussion panel, and provided a much-needed platform for early-career investigators (ECIs) to showcase their research in autophagy. This Perspective summarizes the science presented by the ECIs during the event and discusses the lessons learned from a virtual meeting of this kind during the pandemic. The meeting was a learning experience for all involved, and the ECI participants herein offer their thoughts on the pros and cons of virtual meetings as a modality, either as standalone or hybrid events, with a view towards the post-pandemic world.
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Affiliation(s)
- Jose L Nieto-Torres
- Program of Development, Aging and Regeneration, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | | | - Anais Franco-Romero
- Department of Biomedical Science, University of Padova, via U.Bassi 58b, 35121 Padova, Italy
- Venetian Institute of Molecular Medicine, via Orus 2, 35129 Padova, Italy
| | - Paolo Grumati
- Telethon Institute of Genetics and Medicine, 80078 Pozzuoli, Italy
| | - Carlos M Guardia
- Section on Intracellular Protein Trafficking, Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Andrew M Leidal
- Department of Pathology and Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA 94143-0502, USA
| | - Michael A Mandell
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
- Autophagy, Inflammation and Metabolism Center of Biomedical Research Excellence, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Christina G Towers
- The Salk Institute for Biological Studies, Molecular and Cell Biology Laboratory, 10010 N Torrey Pines Rd, La Jolla, CA 92037-1002, USA
| | - Fei Wang
- UT Southwestern Medical Center, Department of Cell Biology, Dallas, TX 75390-9039, USA
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27
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Nieto-Torres JL, Encalada SE, Hansen M. LC3B phosphorylation: autophagosome's ticket for a ride toward the cell nucleus. Autophagy 2021; 17:3266-3268. [PMID: 34424150 DOI: 10.1080/15548627.2021.1961073] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Macroautophagy/autophagy is a multi-step process that leads to cargo degradation via the fusion of hydrolases-containing lysosomes with cargo-loaded autophagosomes. For this process to occur, autophagosomes are directionally transported by molecular motors toward the nucleus, where they fuse with lysosomes for cargo degradation. The molecular basis for this regulation, including the cell machinery required for this directional transport, has not been fully identified. Using a combination of proteomic and live-imaging approaches in mammalian cells, including primary neurons, we describe that the phosphorylation of the autophagosome protein Atg8/LC3B by the Hippo kinase STK4/MST1, an event we previously reported to be required for autophagy completion, reduces the binding of the transport-related protein FYCO1 to MAP1LC3B/LC3B. This event in turn allows the proficient microtubule-based transport of autophagosomes toward the perinuclear area, thus facilitating the contact of autophagosomes with lysosomes. In the absence of LC3B phosphorylation, autophagosomes undergo aberrant transport including increased movement toward the cell periphery resulting in reduced autophagosome-lysosome colocalization. Thus, LC3B phosphorylation modulates the directional transport of autophagosomes to meet with lysosomes in the perinuclear area, a crucial event in ensuring autophagic degradation of cargo.
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Affiliation(s)
- Jose L Nieto-Torres
- Program of Development, Aging, and Regeneration, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Sandra E Encalada
- Department of Molecular Medicine, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA, USA
| | - Malene Hansen
- Program of Development, Aging, and Regeneration, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
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28
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Barz S, Kriegenburg F, Sánchez-Martín P, Kraft C. Small but mighty: Atg8s and Rabs in membrane dynamics during autophagy. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2021; 1868:119064. [PMID: 34048862 PMCID: PMC8261831 DOI: 10.1016/j.bbamcr.2021.119064] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Figures] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 05/04/2021] [Accepted: 05/21/2021] [Indexed: 11/17/2022]
Abstract
Autophagy is a degradative pathway during which autophagosomes are formed that enwrap cytosolic material destined for turnover within the lytic compartment. Autophagosome biogenesis requires controlled lipid and membrane rearrangements to allow the formation of an autophagosomal seed and its subsequent elongation into a fully closed and fusion-competent double membrane vesicle. Different membrane remodeling events are required, which are orchestrated by the distinct autophagy machinery. An important player among these autophagy proteins is the small lipid-modifier Atg8. Atg8 proteins facilitate various aspects of autophagosome formation and serve as a binding platform for autophagy factors. Also Rab GTPases have been implicated in autophagosome biogenesis. As Atg8 proteins interact with several Rab GTPase regulators, they provide a possible link between autophagy progression and Rab GTPase activity. Here, we review central aspects in membrane dynamics during autophagosome biogenesis with a focus on Atg8 proteins and selected Rab GTPases.
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Affiliation(s)
- Saskia Barz
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany; Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, 79104 Freiburg, Germany
| | - Franziska Kriegenburg
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Pablo Sánchez-Martín
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Claudine Kraft
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; CIBSS - Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany.
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29
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Nieto-Torres JL, Leidal AM, Debnath J, Hansen M. Beyond Autophagy: The Expanding Roles of ATG8 Proteins. Trends Biochem Sci 2021; 46:673-686. [PMID: 33558127 DOI: 10.1016/j.tibs.2021.01.004] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 01/10/2021] [Accepted: 01/12/2021] [Indexed: 12/14/2022]
Abstract
The ATG8 family proteins are critical players in autophagy, a cytoprotective process that mediates degradation of cytosolic cargo. During autophagy, ATG8s conjugate to autophagosome membranes to facilitate cargo recruitment, autophagosome biogenesis, transport, and fusion with lysosomes, for cargo degradation. In addition to these canonical functions, recent reports demonstrate that ATG8s are also delivered to single-membrane organelles, which leads to highly divergent degradative or secretory fates, vesicle maturation, and cargo specification. The association of ATG8s with different vesicles involves complex regulatory mechanisms still to be fully elucidated. Whether individual ATG8 family members play unique canonical or non-canonical roles, also remains unclear. This review summarizes the many open molecular questions regarding ATG8s that are only beginning to be unraveled.
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Affiliation(s)
- Jose L Nieto-Torres
- Sanford Burnham Prebys Medical Discovery Institute, Program of Development, Aging, and Regeneration, La Jolla, CA, USA
| | - Andrew M Leidal
- Department of Pathology and Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA, USA
| | - Jayanta Debnath
- Department of Pathology and Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA, USA.
| | - Malene Hansen
- Sanford Burnham Prebys Medical Discovery Institute, Program of Development, Aging, and Regeneration, La Jolla, CA, USA.
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