Dynamics and diversity in autophagy mechanisms: lessons from yeast

Studies of autophagy in yeast have identified a family of autophagy-related (Atg) proteins, which are required for membrane formation in autophagy. The dynamic assembly of Atg proteins into the pre-autophagosomal structure dictates the localization and activity of the autophagic machinery. Autophagy is a fundamental function of eukaryotic cells and is well conserved from yeast to humans. The most remarkable feature of autophagy is the synthesis of double membrane-bound compartments that sequester materials to be degraded in lytic compartments, a process that seems to be mechanistically distinct from conventional membrane traffic. The discovery of autophagy in yeast and the genetic tractability of this organism have allowed us to identify genes that are responsible for this process, which has led to the explosive growth of this research field seen today. Analyses of autophagy-related (Atg) proteins have unveiled dynamic and diverse aspects of mechanisms that underlie membrane formation during autophagy.