Professor Ronald Thomas Hay FRS
Professor of Molecular Biology, College of Life Sciences, University of Dundee.
Ron Hay is distinguished for establishing conjugation with the Small Ubiquitin-like Modifier (SUMO) as an important regulatory mechanism in eukaryotes. He identified and characterised the enzymes involved in conjugation and deconjugation of ubiqiuitin-like proteins and established several now accepted paradigms for SUMO action. These include the proposal that SUMO and ubiquitin can modify the same lysine residue with quite different consequences and that transcriptional repression mediated by SUMO modified transcription factors is dependent on recruitment of histone deacetylases. He discovered the existence of polySUMO chains and established their role as recognition sites for ubiquitylation mediated by the ubiquitin ligase Rnf4. This targets the Promyelocytic Leukaemia (PML) Protein for arsenic-induced, polySUMO-dependent, ubiquitin-mediated proteolysis, establishing the basis of arsenic therapy in the treatment of leukaemia. He solved the first structure any deubiquitinating enzyme bound to its substrate, revealing that these proteases employ a conserved catalytic mechanism in which a dramatic conformational change in the scissile bond orientates the substrate for cleavage.