Dictyostelium discoideum and autophagy - a perfect pair.

Autophagy is subdivided into chaperone-mediated autophagy, microautophagy and macroautophagy and is a highly conserved intracellular degradative pathway. It is crucial for cellular homeostasis and also serves as a response to different stresses. Here we focus on macroautophagy, which targets damaged organelles and large protein assemblies, as well as pathogenic intracellular microbes for destruction. During this process, cytosolic material becomes enclosed in newly generated double-membrane vesicles, the so-called autophagosomes. Upon maturation, the autophagosome fuses with the lysosome for degradation of the cargo. The basic molecular machinery that controls macroautophagy works in a sequential order and consists of the ATG1 complex, the PtdIns3K complex, the membrane delivery system, two ubiquitin-like conjugation systems, and autophagy adaptors and receptors. Since the different stages of macroautophagy from initiation to final degradation of cargo are tightly regulated and highly conserved across eukaryotes, simple model organisms in combination with a wide range of techniques contributed significantly to advance our understanding of this complex dynamic process. Here, we present the social amoeba Dictyostelium discoideum as an advantageous and relevant experimental model system for the analysis of macroautophagy.