The ubiquitin‐mediated proteolytic pathway and mechanisms of energy‐dependent intracellular protein degradation

In this review we briefly describe the lysosomal system, consider the evidence for multiplicity of protein degradation pathways in vivo, discuss in detail the ubiquitin-mediated pathway of intracellular ATP-dependent protein degradation, and also the possible significance of ubiquitin-histone conjugates in chromatin. For detailed discussions of the various characteristics and physiological roles of intracellular protein breakdown, the reader is referred to earlier reviews 1-7 and reports of recent symposia 8-10. Information on the ubiquitin system prior to 1981 was described in an earlier review 11. Hershko has briefly reviewed more recent information 12.