Xie, Z. & Klionsky, D.J. Autophagosome formation: core machinery and adaptations. Nat. Cell. Biol. 9, 1102-1109

Life Sciences Institute and Department of Molecular, Cellular and Developmental Biology and Biological Chemistry, University of Michigan, Ann Arbor, MI 48109, USA.
Nature Cell Biology (Impact Factor: 19.68). 11/2007; 9(10):1102-9. DOI: 10.1038/ncb1007-1102
Source: PubMed


Eukaryotic cells employ autophagy to degrade damaged or obsolete organelles and proteins. Central to this process is the formation of autophagosomes, double-membrane vesicles responsible for delivering cytoplasmic material to lysosomes. In the past decade many autophagy-related genes, ATG, have been identified that are required for selective and/or nonselective autophagic functions. In all types of autophagy, a core molecular machinery has a critical role in forming sequestering vesicles, the autophagosome, which is the hallmark morphological feature of this dynamic process. Additional components allow autophagy to adapt to the changing needs of the cell.

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    • "Many compelling evidences have been produced about the likely involvement of apoptotic processes intervening during meat maturation [13] [14]. Autophagy is a process designed to maintain homeostasis when it is threatened by starvation or oxidative injuries; it consists in a true selfdigestion of potential toxic, unfolded or misfolded proteins and of entire organelles or portions of cytosol by means of the endosomal/lysosomal pathway [15]. The degree of oxidative stress determines the fate of the damaged cell; when injuries are too much pronounced, the protective autophagic self-digestion can result in autophagic death [16], that has distinguishable features compared to apoptosis regarding morphological, biomarkers and molecular standpoints [17] [18] [19]. "
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    ABSTRACT: Meat derives from a muscle that undergoes a great number of biochemical and physiological changes. The anoxic condition established from the moment of animal sacrifice forces muscle cells to a sort of reaction, resulting in methodical programmed cell death to avoid necrosis. The duality autophagy and/or apoptosis is at the centre of the scientific debate about the biological processes driving the muscle to meat conversion. Here we report an omic time course overview carried on proteome, phosphoproteome and metabolome of Piedmontese Longissimus thoracis muscle searching for clues helping us to extricate through the dilemma. The survey depicts a progressive physiological impairing and our evidences push towards the apoptotic behavior: proteomic time course trend of annexin A2, RKIP, HSPB6, αB crystalline, adenylate kinase, DJ-1, 31 kDa actin fragment; the 0-1 days increased phosphorylation of myosin 2 and synaptopodin; the metabolomic time course trend of key metabolic indicators, like GSH/GSSG ratio, taurine and nitrotyrosine. The employed techniques provide strong indications about the likely apoptotic behavior of aging meat in muscle-to-meat conversion process. Our work underlines compelling evidences of the apoptotic behavior of Piedmontese beef muscle cells undergoing the muscle-to-meat process, whereas no autophagic clues are inferred from this omic investigation. Copyright © 2015. Published by Elsevier B.V.
    Journal of proteomics 05/2015; 125. DOI:10.1016/j.jprot.2015.04.023 · 3.89 Impact Factor
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    • "More than 30 autophagyrelated genes have been identified in yeast, most of which have homologs in plants. These gene products can be divided into several functional groups: the ATG1-ATG13 kinase complex, ATG9 and ATG9-associated proteins, a phosphatidylinositol 3-kinase complex, and two ubiquitin-like conjugation systems (Xie and Klionsky, 2007). Recent studies show that plant autophagy participates in multiple physiological processes, such as nutrient recycling , development, senescence, abiotic stress responses, and pathogen defense (Doelling et al., 2002; Hanaoka et al., 2002; Liu et al., 2005, 2009, 2012; Bassham, 2007; Han et al., 2011). "
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    ABSTRACT: Autophagy as a conserved catabolic pathway can respond to reactive oxygen species (ROS) and plays an important role in degrading oxidized proteins in plants under various stress conditions. However, how ROS regulates autophagy in response to oxidative stresses is largely unknown. Here, we show that autophagy-related protein 3 (ATG3) interacts with the cytosolic glyceraldehyde-3-phosphate dehydrogenases (GAPCs) to regulate autophagy in Nicotiana benthamiana plants. We found that oxidative stress inhibits the interaction of ATG3 with GAPCs. Silencing of GAPCs significantly activates ATG3-dependent autophagy, while overexpression of GAPCs suppresses autophagy in N. benthamiana plants. Moreover, silencing of GAPCs enhances N gene-mediated cell death and plant resistance against both incompatible pathogens Tobacco mosaic virus and Pseudomonas syringae pv tomato DC3000, as well as compatible pathogen P. syringae pv tabaci. These results indicate that GAPCs have multiple functions in the regulation of autophagy, hypersensitive response, and plant innate immunity. © 2015 American Society of Plant Biologists. All rights reserved.
    The Plant Cell 03/2015; 27(4). DOI:10.1105/tpc.114.134692 · 9.34 Impact Factor
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    • "To date 36 ATG genes (Motley et al., 2012) have been identified in yeast, and orthologs of these genes are continuously being discovered in various organisms across the Eukaryota. A subset of ATG genes involved in the formation of autophagosome is referred to as the " core autophagy machinery " , and is conserved in all subtypes of autophagy (Xie and Klionsky, 2007). The core autophagy machinery comprise of genes placed into three major functional categories , namely (i) the Atg9 cycling system which includes Atg9, the Atg1 kinase complex (Atg1 and Atg13), Atg2, and Atg18; (ii) the phosphatidylinositol 3-OH kinase (PI(3)K) complex which includes Vps34, Vps15, Atg6 (Vps30), and Atg14, and (iii) the ubiquitin-like protein (Ubl) system, which includes Atg8-PE complex, the Atg8 modifying protease (Atg4), the Atg12-Atg5.Atg16 complex, the activating enzyme (Atg7), and two analogs of ubiquitin-conjugating enzymes (Atg10 and Atg3) which was reported by Xie and Klionsky (2007). "
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    ABSTRACT: Macroautophagy (hereinafter called autophagy) is a highly regulated process used by eukaryotic cells to digest portions of the cytoplasm that remodels and recycles nutrients and disposes of unwanted cytoplasmic constituents. Currently 36 autophagy-related genes (ATG) and their homologues have been characterized in yeast and higher eukaryotes, including insects. In the present study, we identified and functionally characterized the immune function of an ATG8 homologue in a coleopteran insect, Tenebrio molitor (TmATG8). The cDNA of TmATG8 comprises of an ORF of 363 bp that encodes a protein of 120 amino acid residues. TmATG8 transcripts are detected in all the developmental stages analyzed. TmAtg8 protein contains a highly conserved C-terminal glycine residue (Gly116) and shows high amino acid sequence identity (98%) to its Tribolium castaneum homologue, TcAtg8. Loss of function of TmATG8 by RNAi led to a significant increase in the mortality rates of T. molitor larvae against Listeria monocytogenes. Unlike dsEGFP-treated control larvae, TmATG8-silenced larvae failed to turn-on autophagy in hemocytes after injection with L. monocytogenes. These data suggest that TmATG8 play a role in mediating autophagy-based clearance of Listeria in T. molitor. Copyright © 2015. Published by Elsevier Ltd.
    Developmental & Comparative Immunology 02/2015; 51(1). DOI:10.1016/j.dci.2015.02.017 · 2.82 Impact Factor
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