Intracellular Protein Degradation

Abstract

Publisher Summary This chapter discusses the mechanisms of intracellular protein degradation. Protein degradation occurs in all types of cells. A variety of methods is available for measuring the rate of degradation of proteins within cells. Early studies on protein degradation involved the measurement of rates of degradation of bulk cellular proteins, followed by the use of inhibitors to establish the pathways of degradation. More recently, microinjection and protein engineering techniques have proved valuable tools for the study of the mechanisms of the degradation of individual proteins. The chapter discusses the methods of measuring protein turnover. One of the methods involves labeling with a pulse of radioactive amino acid followed by the measurement of the rate of loss of labeled proteins. Moreover, little is known about the proteolytic enzymes involved in protein turnover. The investigation of the structure and the regulation of recently discovered complex multisubunit proteinases in mammalian cells, yeast, and bacteria promises to be an exciting area of future research.