An overview of macroautophagy in yeast

• Published in: Journal of molecular biology 2016-05, Vol.428 (9), p.1681-1699
• Main Authors: Wen, Xin, Klionsky, Daniel J.
• Format: Article
• Language: English
• Subjects: autophagosome biogenesis; Autophagosomes - metabolism; Autophagy; cargo recognition; Organelle Biogenesis; regulation; Saccharomyces cerevisiae - physiology; stress
• ISSN: 0022-2836; 1089-8638
• DOI: 10.1016/j.jmb.2016.02.021

Macroautophagy is an evolutionarily conserved dynamic pathway that functions primarily in a degradative manner. A basal level of macroautophagy occurs constitutively, but this process can be further induced in response to various types of stress including starvation, hypoxia and hormonal stimuli. The general principle behind macroautophagy is that cytoplasmic contents can be sequestered within a transient double-membrane organelle, an autophagosome, which subsequently fuses with a lysosome or vacuole (in mammals, or yeast and plants, respectively), allowing for degradation of the cargo followed by recycling of the resulting macromolecules. Through this basic mechanism, macroautophagy has a critical role in cellular homeostasis; however, either insufficient or excessive macroautophagy can seriously compromise cell physiology, and thus, it needs to be properly regulated. In fact, a wide range of diseases are associated with dysregulation of macroautophagy. There has been substantial progress in understanding the regulation and molecular mechanisms of macroautophagy in different organisms; however, many questions concerning some of the most fundamental aspects of macroautophagy remain unresolved. In this review, we summarize current knowledge about macroautophagy mainly in yeast, including the mechanism of autophagosome biogenesis, the function of the core macroautophagic machinery, the regulation of macroautophagy and the process of cargo recognition in selective macroautophagy, with the goal of providing insights into some of the key unanswered questions in this field. [Display omitted] •Among the different types of autophagy, macroautophagy is the best characterized.•The biogenesis of the phagophore or autophagosome is a key step in the process.•Tight regulation of macroautophagy is important for normal cellular function.•Autophagy-related proteins that form the autophagosome constitute the core machinery.•Macroautophagy can be nonselective or selective for specific cargos.