Intracellular proteolysis

Our present understanding of intracellular protein degradation developed fr om an attempt to understand the metabolic stability of proteins in cells. W ith the unravelling of its complex biochemical machinery has come a realiza tion that protein degradation plays an important role in the most crucial e vents in the cell cycle, in signal transduction and in maintaining the inte grity of the proper folded state of proteins. In this review, I attempt to trace the curious history of intracellular protein degradation, its novel a nd elegant biochemistry and to extract the features that might be important for the next era of studies in cell physiology.