The FASEB Conference on Ubiquitin and Intracellular Protein Degradation will bring together scientists studying the different systems which regulate protein breakdown within the cell as well as those studying ubiquitin genes, their expression and their potential regulatory roles in cell metabolism. Ubiquitin was first isolated and characterized about 15 years ago as a major protein extract with strong mitogenic activity. Based on specific antibodies, its presence was detected in many biological species. Its sequence of 76 amino acids was determined from several species and shown to be surprisingly conserved. The purified ubiquitin was found not to be a mitogen but its first function was detected when it was identified as the cofactor required in an ATP-dependent pathway for degradation of proteins. Until recently, this was ubiquitin's only apparent role in the cell. However, the isolation of genes encoding ubiquitin revealed additonal sites for its function - in particular in DNA repair and ribosomal RNA synthesis. A role in DNA metabolism had been suggested from the early detection of ubiquitin sequences covalently linked to histone H2A and H2B in interphase chromatin. Similar ubiquitin-conjugates have been found in insect muscle actin, in cell surface receptors, in virus structural proteins and in cytoskeleton proteins. An increasing number of scientists from widely divergent disciplines are studying the role of ubiquitin in conjugates, their relationship to the ATP-dependent proteolytic degradation system (which has been found essential for normal cell growth and metabolism), the factors that regulate expression of ubiquitin and the meaning of the unusual and unique organization of ubiquitin genes. This conference will bring these investigators together in an atmosphere that will provide meaningful exchange of the latest developments in these areas of research which will contribute to our understanding of basic cell functions.
