Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Review Article
  • Published:

Autophagy in metazoans: cell survival in the land of plenty

Key Points

  • Autophagy is a universally conserved response to nutrient limitation in which organisms respond to metabolic 'emergencies' by breaking down cytoplasmic proteins and organelles. The existence of autophagy in diverse organisms has been recognized for decades, but the functions of autophagy in mammals are still not fully understood.

  • In metazoans, metabolite supply is controlled by growth factor regulation of nutrient uptake, and decreased growth factor signalling permits the induction of autophagy. In various metazoan organisms, autophagy supports cell survival in such circumstances.

  • At the molecular level, the induction of autophagy seems to be linked to well-known mechanisms of intracellular nutrient sensing. In particular, the serine/threonine kinase mTOR promotes cap-dependent protein translation, and is therefore vital for the anabolic effects of growth factor signal transduction. By contrast, the inhibition of mTOR activity is associated with the induction of autophagy.

  • The benefits that autophagy provides to metazoan cells might include metabolite recycling for adaptive synthetic reactions or ATP production, and degradation of damaged or unnecessary material. In addition, autophagy is now recognized as a form of innate immunity against various intracellular pathogens.

  • Dysregulation of autophagy has been implicated in various pathological conditions, including tumorigenesis and neurodegeneration. In some circumstances, autophagy functions as a non-apoptotic form of cell death. The complexity of these responses is an active area of research and underlines the importance of autophagy in mammalian physiology.

Abstract

Cells require a constant supply of macromolecular precursors and oxidizable substrates to maintain viability. Unicellular eukaryotes lack the ability to regulate nutrient concentrations in their extracellular environment. So when environmental nutrients are depleted, these organisms catabolize existing cytoplasmic components to support ATP production to maintain survival, a process known as autophagy. By contrast, the environment of metazoans normally contains abundant extracellular nutrients, but a cell's ability to take up these nutrients is controlled by growth factor signal transduction. Despite evolving the ability to maintain a constant supply of extracellular nutrients, metazoans have retained a complete set of autophagy genes. The physiological relevance of autophagy in such species is just beginning to be explored.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Growth factor signalling regulates autophagy.
Figure 2: A model for growth factor control of intermediate metabolism and autophagy.
Figure 3: Coordinated regulation of nutrient sensing by mTOR and AMPK.
Figure 4: Model for the metabolic benefits of autophagy.

Similar content being viewed by others

References

  1. Edinger, A. L., Cinalli, R. M. & Thompson, C. B. Rab7 prevents growth factor-independent survival by inhibiting cell-autonomous nutrient transporter expression. Dev. Cell 5, 571–582 (2003).

    CAS  PubMed  Google Scholar 

  2. Alessi, D. R. & Downes, C. P. The role of PI3-kinase in insulin action. Biochim. Biophys. Acta 1436, 151–164 (1998).

    CAS  PubMed  Google Scholar 

  3. Barata, J. T. et al. Activation of PI3K is indispensable for interleukin 7-mediated viability, proliferation, glucose use, and growth of T cell acute lymphoblastic leukemia cells. J. Exp. Med. 200, 659–669 (2004).

    CAS  PubMed  PubMed Central  Google Scholar 

  4. Kirkegaard, K., Taylor, M. P. & Jackson, W. T. Cellular autophagy: surrender, avoidance and subversion by microorganisms. Nature Rev. Microbiol. 2, 301–314 (2004).

    CAS  Google Scholar 

  5. Meijer, A. J. & Codogno, P. Regulation and role of autophagy in mammalian cells. Int. J. Biochem. Cell Biol. 36, 2445–2462 (2004).

    CAS  PubMed  Google Scholar 

  6. Yoshimori, T. Autophagy: a regulated bulk degradation process inside cells. Biochem. Biophys. Res. Commun. 313, 453–458 (2004).

    CAS  PubMed  Google Scholar 

  7. Levine, B. & Klionsky, D. J. Development by self-digestion: molecular mechanisms and biological functions of autophagy. Dev. Cell 6, 463–477 (2004).

    CAS  PubMed  Google Scholar 

  8. Gozuacik, D. & Kimchi, A. Autophagy as a cell death and tumor suppressor mechanism. Oncogene 23, 2891–2906 (2004).

    CAS  PubMed  Google Scholar 

  9. Huang, W. P. & Klionsky, D. J. Autophagy in yeast: a review of the molecular machinery. Cell Struct. Funct. 27, 409–420 (2002).

    CAS  PubMed  Google Scholar 

  10. Noda, T., Suzuki, K. & Ohsumi, Y. Yeast autophagosomes: de novo formation of a membrane structure. Trends Cell Biol. 12, 231–235 (2002).

    CAS  PubMed  Google Scholar 

  11. Ohsumi, Y. Molecular dissection of autophagy: two ubiquitin-like systems. Nature Rev. Mol. Cell Biol. 2, 211–216 (2001).

    CAS  Google Scholar 

  12. Petiot, A. et al. Diversity of signaling controls of macroautophagy in mammalian cells. Cell Struct. Funct. 27, 431–441 (2002).

    PubMed  Google Scholar 

  13. Tsukada, M. & Ohsumi, Y. Isolation and characterization of autophagy-defective mutants of Saccharomyces cerevisiae. FEBS Lett. 333, 169–174 (1993). Shows the involvement of autophagy in maintaining survival of unicellular organisms during nutrient deprivation. Using a genetic screen to isolate yeast cells that are unable to form autophagic vacuoles, the authors identified the first set of autophagy genes, which provided the foundation for the discovery of homologues in higher eukaryotes.

    CAS  PubMed  Google Scholar 

  14. Otto, G. P. et al. Macroautophagy is required for multicellular development of the social amoeba Dictyostelium discoideum. J. Biol. Chem. 278, 17636–17645 (2003).

    CAS  PubMed  Google Scholar 

  15. Otto, G. P. et al. Dictyostelium macroautophagy mutants vary in the severity of their developmental defects. J. Biol. Chem. 279, 15621–15629 (2004).

    CAS  PubMed  Google Scholar 

  16. Journet, E. P., Bligny, R. & Douce, R. Biochemical changes during sucrose deprivation in higher plant cells. J. Biol. Chem. 261, 3193–3199 (1986).

    CAS  PubMed  Google Scholar 

  17. Aubert, S. et al. Ultrastructural and biochemical characterization of autophagy in higher plant cells subjected to carbon deprivation: control by the supply of mitochondria with respiratory substrates. J. Cell Biol. 133, 1251–1263 (1996). Work by the group in reference 16 showed that plants experience decreased glycolytic enzymatic activity, growth arrest and a decline in respiration during nutrient withdrawal. Reference 17 shows that autophagy is controlled by the levels of oxidizable substrates for the mitochondria and not by carbon sugar deprivation.

    CAS  PubMed  Google Scholar 

  18. Hanaoka, H. et al. Leaf senescence and starvation-induced chlorosis are accelerated by the disruption of an Arabidopsis autophagy gene. Plant Physiol. 129, 1181–1193 (2002).

    CAS  PubMed  PubMed Central  Google Scholar 

  19. Yoshimoto, K. et al. Processing of ATG8s, ubiquitin-like proteins, and their deconjugation by ATG4s are essential for plant autophagy. Plant Cell 16, 2967–2983 (2004).

    CAS  PubMed  PubMed Central  Google Scholar 

  20. Doelling, J. H., Walker, J. M., Friedman, E. M., Thompson, A. R. & Vierstra, R. D. The APG8/12-activating enzyme APG7 is required for proper nutrient recycling and senescence in Arabidopsis thaliana. J. Biol. Chem. 277, 33105–33114 (2002).

    CAS  PubMed  Google Scholar 

  21. Melendez, A. et al. Autophagy genes are essential for dauer development and life-span extension in C. elegans. Science 301, 1387–1391 (2003).

    CAS  PubMed  Google Scholar 

  22. Scott, R. C., Schuldiner, O. & Neufeld, T. P. Role and regulation of starvation-induced autophagy in the Drosophila fat body. Dev. Cell 7, 167–178 (2004).

    CAS  PubMed  Google Scholar 

  23. Kuma, A. et al. The role of autophagy during the early neonatal starvation period. Nature 432, 963 (2004). Describes the first genetic demonstration for the in vivo requirement of autophagy in early neonatal mammal survival during nutrient starvation. Atg5 -knockout neonatal mice have a severe reduction in the ability to survive up to the establishment of their ability to be nursed by their mothers. It follows from several observations (see references 24–27) that associated the degradation of glycogen in autophagosomes during early neonatal periods.

    Google Scholar 

  24. Schiaffino, S. & Hanzlikova, V. Autophagic degradation of glycogen in skeletal muscles of the newborn rat. J. Cell Biol. 52, 41–51 (1972).

    CAS  PubMed  PubMed Central  Google Scholar 

  25. Devos, P. & Hers, H. G. Random, presumably hydrolytic, and lysosomal glycogenolysis in the livers of rats treated with phlorizin and of newborn rats. Biochem. J. 192, 177–181 (1980).

    CAS  PubMed  PubMed Central  Google Scholar 

  26. Iwamasa, T., Tsuru, T., Hamada, T. & Takeuchi, T. Physicochemical and ultrastructural studies on glycogenosomes in newborn rat hepatocytes. Pathol. Res. Pract. 167, 363–373 (1980).

    CAS  PubMed  Google Scholar 

  27. Kondomerkos, D. J., Kalamidas, S. A. & Kotoulas, O. B. An electron microscopic and biochemical study of the effects of glucagon on glycogen autophagy in the liver and heart of newborn rats. Microsc. Res. Tech. 63, 87–93 (2004).

    CAS  PubMed  Google Scholar 

  28. Wei, M. C. et al. Proapoptotic BAX and BAK: a requisite gateway to mitochondrial dysfunction and death. Science 292, 727–730 (2001).

    CAS  PubMed  PubMed Central  Google Scholar 

  29. Zong, W. X. et al. Alkylating DNA damage stimulates a regulated form of necrotic cell death. Genes Dev. 18, 1272–1282 (2004).

    CAS  PubMed  PubMed Central  Google Scholar 

  30. Zong, W. X. et al. BH3-only proteins that bind pro-survival Bcl-2 family members fail to induce apoptosis in the absence of Bax and Bak. Genes Dev. 15, 1481–1486 (2001).

    CAS  PubMed  PubMed Central  Google Scholar 

  31. Lum, J. J. et al. Growth factor regulation of autophagy and survival in the absence of apoptosis. Cell 120, 237–248 (2005).

    CAS  PubMed  Google Scholar 

  32. Petiot, A. et al. Distinct classes of phosphatidylinositol 3′-kinases are involved in signaling pathways that control macroautophagy in HT-29 cells. J. Biol. Chem. 275, 992–998 (2000). Shows that class-I and class-III PI3K cascades have distinct effects on autophagy. Autophagy can be blocked by class-I PI3K inhibitors, which allows new insight into the signal transduction cascades of how autophagy is regulated.

    CAS  PubMed  Google Scholar 

  33. Kihara, A. et al. Beclin–phosphatidylinositol 3-kinase complex functions at the trans-Golgi network. EMBO Rep. 2, 330–335 (2001).

    CAS  PubMed  PubMed Central  Google Scholar 

  34. Whetton, A. D., Bazill, G. W. & Dexter, T. M. Haemopoietic cell growth factor mediates cell survival via its action on glucose transport. EMBO J. 3, 409–413 (1984).

    CAS  PubMed  PubMed Central  Google Scholar 

  35. Vander Heiden, M. G. et al. Growth factors can influence cell growth and survival through effects on glucose metabolism. Mol. Cell. Biol. 21, 5899–5912 (2001).

    CAS  PubMed  PubMed Central  Google Scholar 

  36. Edinger, A. L. & Thompson, C. B. Akt maintains cell size and survival by increasing mTOR-dependent nutrient uptake. Mol. Biol. Cell 13, 2276–2288 (2002).

    CAS  PubMed  PubMed Central  Google Scholar 

  37. Bentley, J. et al. Interleukin-3-mediated cell survival signals include phosphatidylinositol 3-kinase-dependent translocation of the glucose transporter GLUT1 to the cell surface. J. Biol. Chem. 278, 39337–39348 (2003).

    CAS  PubMed  Google Scholar 

  38. Bauer, D. E. et al. Cytokine stimulation of aerobic glycolysis in hematopoietic cells exceeds proliferative demand. FASEB J. 18, 1303–1305 (2004).

    CAS  PubMed  Google Scholar 

  39. Hirai, S. et al. Fibroblast growth factor-dependent metabolism of hypoxanthine via the salvage pathway for purine synthesis in porcine aortic endothelial cells. Biochem. Pharmacol. 45, 1695–1701 (1993).

    CAS  PubMed  Google Scholar 

  40. Ishijima, S. et al. Evidence for early mitogenic stimulation of metabolic flux through phosphoribosyl pyrophosphate into nucleotides in Swiss 3T3 cells. J. Biochem. 104, 570–575 (1988).

    CAS  PubMed  Google Scholar 

  41. del Santo, B. et al. Differential expression and regulation of nucleoside transport systems in rat liver parenchymal and hepatoma cells. Hepatology 28, 1504–1511 (1998).

    CAS  PubMed  Google Scholar 

  42. Becker, M. A., Dicker, P. & Rozengurt, E. Mitogenic enhancement of purine base phosphoribosylation in Swiss mouse 3T3 cells. Am. J. Physiol. 244, C288–C296 (1983).

    CAS  PubMed  Google Scholar 

  43. Plas, D. R. et al. Akt and Bcl-xL promote growth factor-independent survival through distinct effects on mitochondrial physiology. J. Biol. Chem. 276, 12041–12048 (2001).

    CAS  PubMed  Google Scholar 

  44. Rathmell, J. C. et al. Akt-directed glucose metabolism can prevent Bax conformation change and promote growth factor-independent survival. Mol. Cell. Biol. 23, 7315–7328 (2003).

    CAS  PubMed  PubMed Central  Google Scholar 

  45. Elstrom, R. L. et al. Akt stimulates aerobic glycolysis in cancer cells. Cancer Res. 64, 3892–3899 (2004).

    CAS  PubMed  Google Scholar 

  46. Hardie, D. G., Carling, D. & Carlson, M. The AMP-activated/SNF1 protein kinase subfamily: metabolic sensors of the eukaryotic cell? Annu. Rev. Biochem. 67, 821–855 (1998).

    CAS  PubMed  Google Scholar 

  47. Hay, N. & Sonenberg, N. Upstream and downstream of mTOR. Genes Dev. 18, 1926–1945 (2004).

    CAS  PubMed  Google Scholar 

  48. Brown, E. J. & Schreiber, S. L. A signaling pathway to translational control. Cell 86, 517–520 (1996).

    CAS  PubMed  Google Scholar 

  49. Tokunaga, C., Yoshino, K. & Yonezawa, K. mTOR integrates amino acid- and energy-sensing pathways. Biochem. Biophys. Res. Commun. 313, 443–446 (2004).

    CAS  PubMed  Google Scholar 

  50. Raught, B., Gingras, A. C. & Sonenberg, N. The target of rapamycin (TOR) proteins. Proc. Natl Acad. Sci. USA 98, 7037–7044 (2001).

    CAS  PubMed  PubMed Central  Google Scholar 

  51. Bjornsti, M. A. & Houghton, P. J. The TOR pathway: a target for cancer therapy. Nature Rev. Cancer 4, 335–348 (2004).

    CAS  Google Scholar 

  52. Fingar, D. C. & Blenis, J. Target of rapamycin (TOR): an integrator of nutrient and growth factor signals and coordinator of cell growth and cell cycle progression. Oncogene 23, 3151–3171 (2004).

    CAS  PubMed  Google Scholar 

  53. Tee, A. R. et al. Tuberous sclerosis complex gene products, Tuberin and Hamartin, control mTOR signaling by acting as a GTPase-activating protein complex toward Rheb. Curr. Biol. 13, 1259–1268 (2003).

    CAS  PubMed  Google Scholar 

  54. Inoki, K. et al. Rheb GTPase is a direct target of TSC2 GAP activity and regulates mTOR signaling. Genes Dev. 17, 1829–1834 (2003).

    CAS  PubMed  PubMed Central  Google Scholar 

  55. Dennis, P. B. et al. Mammalian TOR: a homeostatic ATP sensor. Science 294, 1102–1105 (2001).

    CAS  PubMed  Google Scholar 

  56. Krause, U., Bertrand, L. & Hue, L. Control of p70 ribosomal protein S6 kinase and acetyl-CoA carboxylase by AMP-activated protein kinase and protein phosphatases in isolated hepatocytes. Eur. J. Biochem. 269, 3751–3759 (2002).

    CAS  PubMed  Google Scholar 

  57. Dubbelhuis, P. F. & Meijer, A. J. Hepatic amino acid-dependent signaling is under the control of AMP-dependent protein kinase. FEBS Lett. 521, 39–42 (2002).

    CAS  PubMed  Google Scholar 

  58. Bolster, D. R. et al. AMP-activated protein kinase suppresses protein synthesis in rat skeletal muscle through down-regulated mammalian target of rapamycin (mTOR) signaling. J. Biol. Chem. 277, 23977–23980 (2002).

    CAS  PubMed  Google Scholar 

  59. Larsen, A. K. et al. Naringin-sensitive phosphorylation of plectin, a cytoskeletal cross-linking protein, in isolated rat hepatocytes. J. Biol. Chem. 277, 34826–34835 (2002).

    CAS  PubMed  Google Scholar 

  60. Inoki, K., Zhu, T. & Guan, K. L. TSC2 mediates cellular energy response to control cell growth and survival. Cell 115, 577–590 (2003).

    CAS  PubMed  Google Scholar 

  61. Potter, C. J., Pedraza, L. G. & Xu, T. Akt regulates growth by directly phosphorylating Tsc2. Nature Cell Biol. 4, 658–665 (2002).

    CAS  PubMed  Google Scholar 

  62. Blommaart, E. F. et al. Phosphorylation of ribosomal protein S6 is inhibitory for autophagy in isolated rat hepatocytes. J. Biol. Chem. 270, 2320–2326 (1995).

    CAS  PubMed  Google Scholar 

  63. Noda, T. & Ohsumi, Y. Tor, a phosphatidylinositol kinase homologue, controls autophagy in yeast. J. Biol. Chem. 273, 3963–3966 (1998).

    CAS  PubMed  Google Scholar 

  64. Abeliovich, H. et al. Dissection of autophagosome biogenesis into distinct nucleation and expansion steps. J. Cell Biol. 151, 1025–1034 (2000).

    CAS  PubMed  PubMed Central  Google Scholar 

  65. Kamada, Y., Sekito, T. & Ohsumi, Y. Autophagy in yeast: a TOR-mediated response to nutrient starvation. Curr. Top. Microbiol. Immunol. 279, 73–84 (2004).

    CAS  PubMed  Google Scholar 

  66. Wang, Z. Antagonistic controls of autophagy and glycogen accumulation by Snf1p, the yeast homolog of AMP-activated protein kinase, and the cyclin-dependent kinase Pho85p. Mol. Cell. Biol. 21, 5742–5752 (2001).

    CAS  PubMed  PubMed Central  Google Scholar 

  67. Danial, N. N. et al. BAD and glucokinase reside in a mitochondrial complex that integrates glycolysis and apoptosis. Nature 424, 952–956 (2003).

    CAS  PubMed  Google Scholar 

  68. Peng, T., Golub, T. R. & Sabatini, D. M. The immunosuppressant rapamycin mimics a starvation-like signal distinct from amino acid and glucose deprivation. Mol. Cell. Biol. 22, 5575–5584 (2002).

    CAS  PubMed  PubMed Central  Google Scholar 

  69. Elmore, S. P. et al. The mitochondrial permeability transition initiates autophagy in rat hepatocytes. FASEB J. 15, 2286–2287 (2001).

    CAS  PubMed  Google Scholar 

  70. Lang-Rollin, I. C. et al. Mechanisms of caspase-independent neuronal death: energy depletion and free radical generation. J. Neurosci. 23, 11015–11025 (2003).

    CAS  PubMed  PubMed Central  Google Scholar 

  71. Xue, L., Fletcher, G. C. & Tolkovsky, A. M. Mitochondria are selectively eliminated from eukaryotic cells after blockade of caspases during apoptosis. Curr. Biol. 11, 361–365 (2001).

    CAS  PubMed  Google Scholar 

  72. Lemasters, J. J. et al. The mitochondrial permeability transition in cell death: a common mechanism in necrosis, apoptosis and autophagy. Biochim. Biophys. Acta 1366, 177–196 (1998).

    CAS  PubMed  Google Scholar 

  73. Kissova, I. et al. Uth1p is involved in the autophagic degradation of mitochondria. J. Biol. Chem. 279, 39068–39074 (2004).

    CAS  PubMed  Google Scholar 

  74. Kiel, J. A. et al. Macropexophagy in Hansenula polymorpha: facts and views. FEBS Lett. 549, 1–6 (2003).

    CAS  PubMed  Google Scholar 

  75. Bellu, A. R. et al. Peroxisome biogenesis and selective degradation converge at Pex14p. J. Biol. Chem. 276, 44570–44574 (2001).

    CAS  PubMed  Google Scholar 

  76. Bjornsti, M. A. & Houghton, P. J. Lost in translation: dysregulation of cap-dependent translation and cancer. Cancer Cell 5, 519–523 (2004).

    CAS  PubMed  Google Scholar 

  77. Sawyers, C. L. Will mTOR inhibitors make it as cancer drugs? Cancer Cell 4, 343–348 (2003).

    CAS  PubMed  Google Scholar 

  78. Qu, X. et al. Promotion of tumorigenesis by heterozygous disruption of the beclin 1 autophagy gene. J. Clin. Invest. 112, 1809–1820 (2003).

    CAS  PubMed  PubMed Central  Google Scholar 

  79. Yue, Z. et al. Beclin 1, an autophagy gene essential for early embryonic development, is a haploinsufficient tumor suppressor. Proc. Natl Acad. Sci. USA 100, 15077–15082 (2003). References 78 and 79 describe the first experimental evidence that genetic inactivation of beclin-1 resulted in a high frequency of tumour formation. These mice had both lower basal levels of autophagy and defective autophagic responses.

    CAS  PubMed  PubMed Central  Google Scholar 

  80. Kanzawa, T. et al. Induction of autophagic cell death in malignant glioma cells by arsenic trioxide. Cancer Res. 63, 2103–2108 (2003).

    CAS  PubMed  Google Scholar 

  81. Kanzawa, T. et al. Role of autophagy in temozolomide-induced cytotoxicity for malignant glioma cells. Cell Death Differ. 11, 448–457 (2004).

    CAS  PubMed  Google Scholar 

  82. Paglin, S. et al. A novel response of cancer cells to radiation involves autophagy and formation of acidic vesicles. Cancer Res. 61, 439–444 (2001).

    CAS  PubMed  Google Scholar 

  83. Bursch, W. The autophagosomal-lysosomal compartment in programmed cell death. Cell Death Differ. 8, 569–581 (2001).

    CAS  PubMed  Google Scholar 

  84. Yu, L. et al. Regulation of an ATG7-beclin 1 program of autophagic cell death by caspase-8. Science 304, 1500–1502 (2004). The authors describe how autophagic cell death is regulated by the caspase-8 pathway. Induction of autophagy by a general caspase inhibitor promotes autophagy and is prevented by knockdown of ATG7 and beclin-1.

    CAS  PubMed  Google Scholar 

  85. Juhasz, G. et al. The Drosophila homolog of Aut1 is essential for autophagy and development. FEBS Lett. 543, 154–158 (2003).

    CAS  PubMed  Google Scholar 

  86. Zhu, J. H. et al. Localization of phosphorylated ERK/MAP kinases to mitochondria and autophagosomes in Lewy body diseases. Brain Pathol. 13, 473–481 (2003).

    CAS  PubMed  Google Scholar 

  87. Stefanis, L. et al. Expression of A53T mutant but not wild-type α-synuclein in PC12 cells induces alterations of the ubiquitin-dependent degradation system, loss of dopamine release, and autophagic cell death. J. Neurosci. 21, 9549–9560 (2001).

    CAS  PubMed  PubMed Central  Google Scholar 

  88. Ravikumar, B. et al. Inhibition of mTOR induces autophagy and reduces toxicity of polyglutamine expansions in fly and mouse models of Huntington disease. Nature Genet. 36, 585–595 (2004).

    CAS  PubMed  Google Scholar 

  89. Qin, Z. H. et al. Autophagy regulates the processing of amino terminal huntingtin fragments. Hum. Mol. Genet. 12, 3231–3244 (2003).

    CAS  PubMed  Google Scholar 

  90. Anglade, P. et al. Apoptosis and autophagy in nigral neurons of patients with Parkinson's disease. Histol. Histopathol. 12, 25–31 (1997).

    CAS  PubMed  Google Scholar 

  91. Petersen, A. et al. Expanded CAG repeats in exon 1 of the Huntington's disease gene stimulate dopamine-mediated striatal neuron autophagy and degeneration. Hum. Mol. Genet. 10, 1243–1254 (2001).

    CAS  PubMed  Google Scholar 

  92. Gomez-Santos, C. et al. Dopamine induces autophagic cell death and α-synuclein increase in human neuroblastoma SH-SY5Y cells. J. Neurosci. Res. 73, 341–350 (2003).

    CAS  PubMed  Google Scholar 

  93. Nakagawa, I. et al. Autophagy defends cells against invading group A Streptococcus. Science 306, 1037–1040 (2004).

    CAS  PubMed  Google Scholar 

  94. Rich, K. A., Burkett, C. & Webster, P. Cytoplasmic bacteria can be targets for autophagy. Cell. Microbiol. 5, 455–468 (2003).

    CAS  PubMed  Google Scholar 

  95. Ogawa, M. et al. Escape of intracellular shigella from autophagy. Science 307, 727–731 (2004).

    PubMed  Google Scholar 

  96. Furuta, S. et al. Ras is involved in the negative control of autophagy through the class I PI3-kinase. Oncogene 23, 3898–3904 (2004).

    CAS  PubMed  Google Scholar 

  97. Tsuneoka, M. et al. c-myc induces autophagy in rat 3Y1 fibroblast cells. Cell Struct. Funct. 28, 195–204 (2003).

    CAS  PubMed  Google Scholar 

  98. Arico, S. et al. The tumor suppressor PTEN positively regulates macroautophagy by inhibiting the phosphatidylinositol 3-kinase/protein kinase B pathway. J. Biol. Chem. 276, 35243–35246 (2001).

    CAS  PubMed  Google Scholar 

  99. Liang, X. H. et al. Beclin 1 contains a leucine-rich nuclear export signal that is required for its autophagy and tumor suppressor function. Cancer Res. 61, 3443–3449 (2001).

    CAS  PubMed  Google Scholar 

  100. Schreiber, S. L. Chemistry and biology of the immunophilins and their immunosuppressive ligands. Science 251, 283–287 (1991).

    CAS  PubMed  Google Scholar 

  101. Shimizu, S. et al. Role of Bcl-2 family proteins in a non-apoptotic programmed cell death dependent on autophagy genes. Nature Cell Biol. 6, 1221–1228 (2004).

    CAS  PubMed  Google Scholar 

  102. Bursch, W. et al. Active cell death induced by the anti-estrogens tamoxifen and ICI 164 384 in human mammary carcinoma cells (MCF-7) in culture: the role of autophagy. Carcinogenesis 17, 1595–1607 (1996).

    CAS  PubMed  Google Scholar 

  103. van Blitterswijk, W. J. et al. Ceramide: second messenger or modulator of membrane structure and dynamics? Biochem. J. 369, 199–211 (2003).

    CAS  PubMed  PubMed Central  Google Scholar 

  104. Suzuki, E. et al. Sphingosine-dependent apoptosis: a unified concept based on multiple mechanisms operating in concert. Proc. Natl Acad. Sci. USA 101, 14788–14793 (2004).

    CAS  PubMed  PubMed Central  Google Scholar 

  105. Scarlatti, F. et al. Ceramide-mediated macroautophagy involves inhibition of protein kinase B and up-regulation of beclin 1. J. Biol. Chem. 279, 18384–18391 (2004).

    CAS  PubMed  Google Scholar 

  106. Daido, S. et al. Pivotal role of the cell death factor BNIP3 in ceramide-induced autophagic cell death in malignant glioma cells. Cancer Res. 64, 4286–4293 (2004).

    CAS  PubMed  Google Scholar 

  107. Mizushima, N. et al. In vivo analysis of autophagy in response to nutrient starvation using transgenic mice expressing a fluorescent autophagosome marker. Mol. Biol. Cell 15, 1101–1111 (2004).

    CAS  PubMed  PubMed Central  Google Scholar 

  108. Kabeya, Y. et al. LC3, a mammalian homologue of yeast Apg8p, is localized in autophagosome membranes after processing. EMBO J. 19, 5720–5728 (2000). References 107 and 108 describe the mammalian homologue of ATG8, LC3, as a specific marker of autophagosome formation.

    CAS  PubMed  PubMed Central  Google Scholar 

Download references

Acknowledgements

The authors wish to thank Daniel E. Bauer for insightful comments and suggestions during the preparation of this review. Julian J. Lum is supported by a fellowship from the Leukemia and Lymphoma Society. Ralph J. DeBerardinis is supported by a grant from the National Institutes of Health. Grants for the Thompson laboratory are provided in part by the National Institutes of Health.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Craig B. Thompson.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Related links

Related links

DATABASES

Entrez Gene

ATG1

ATG5

ATG6

ATG7

ATG8

ATG10

daf-2

PTEN

Swiss-Prot

Bak

Bax

CPT1

4E-BP1

Pex14

Rheb

S6K

TSC1

TSC2

Uth1

Glossary

OXIDIZABLE SUBSTRATE

A molecule that can be used in mitochondrial oxidation/reduction reactions to yield reduced electron carriers (NADH, FADH2). In this review, we consider oxidizable substrates to be molecules that provide carbon to the tricarboxylic acid cycle.

EXTRACELLULAR NUTRIENT

A resource in the environment that can be passively or actively taken up by cells and used in intermediate metabolism. These include amino acids, fatty acids, glucose, nucleotides and minerals.

GROWTH FACTOR

A small molecule that binds to lineage-specific cell-surface receptors and activates signal transduction pathways necessary for cell growth, proliferation and survival. Examples of growth factors include insulin, platelet-derived growth factor and cytokines.

ANABOLIC METABOLISM

(anabolism). A collective term for metabolic pathways in which simple metabolites are used to synthesize macromolecules. Examples include the synthesis of proteins from amino acids and of lipids from acetyl CoA. Anabolism is required for cell growth, is stimulated by growth factors and generally consumes ATP.

CATABOLIC METABOLISM

(catabolism). A collective term for metabolic pathways that degrade macromolecules to yield simpler constituents and/or ATP, usually during periods of nutrient deprivation. Examples include β-oxidation of fatty acids and glycogenolysis. Autophagy is considered as an arm of catabolism, because it includes protein degradation in response to nutritional stress.

MACROAUTOPHAGY

(autophagy). A process whereby double-membrane structures sequester cytosolic material and fuse to a lysosome or vacuole. Material within these structures is degraded and recycled.

RAPAMYCIN

(also known as sirolimus). A peptide from the bacterium Streptomyces hygroscopicus, isolated from the soil on Easter Island. It is an inhibitor of Tor activity and functions as a potent immunosuppressant.

β-OXIDATION

A metabolic process in the mitochondria that uses fatty acids as substrates. The pathway consists of a repeating cycle of four reactions that yield acetyl CoA and reduced electron carriers. It is a source of both ATP and oxidizable substrates.

CAP-DEPENDENT TRANSLATION

Protein translation of mRNAs that are capped with 7-methyl-guanine.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Lum, J., DeBerardinis, R. & Thompson, C. Autophagy in metazoans: cell survival in the land of plenty. Nat Rev Mol Cell Biol 6, 439–448 (2005). https://doi.org/10.1038/nrm1660

Download citation

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nrm1660

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing