Review Methods for monitoring autophagy

Autophagy is an intracellular bulk degradation system that is found ubiquitously in eukaryotes. Autophagy is responsi-ble for the degradation of most long-lived proteins and some organelles. Cytoplasmic constituents, including organelles, are sequestered into double-membraned autophagosomes, which subsequently fuse with lysosomes where their contents are degraded. This system has been implicated in various physiological processes including protein and organelle turnover, the star-vation response, cellular differentiation, cell death, and pathogenesis. However, methods for monitoring autophagy have been very limited and unsatisfactory. The most standard method is conventional electron microscopy. In addition, some biochemical methods have been utilized to measure autophagic activity. Recently, the molecular basis of autophagosome formation has been extensively studied using yeast cells; these studies have provided useful marker proteins for autophagosomes. Importantly