Arthur L Haas, PhD, Professor and Chairman of the Department of Biochemistry, Louisiana State University School of Medicine, New Orleans, is a pioneer in the biochemistry and enzymology of ubiquitin pathway enzymes. He earned a PhD degree in Biochemistry from Northwestern University, Chicago, IL, and received his postdoctoral training in the laboratory of Dr. Irwin Rose, one of three scientists awarded the 2004 Nobel Prize in Chemistry for their discovery and elaboration of the ubiquitin pathway.
Dr Haas published the first biochemical kinetics studies of the three enzymes (E1, E2, and E3) responsible for attaching ubiquitin to its target protein, and has long been regarded as a pioneer in the field of ubiquitin biochemistry. Dr Haas’ lab recently identified a second constitutive cell system that is parallel but distinct from ubiquitin in which the 15 kDa interferon-like protein ISG15/UCRP is conjugated to a smaller subset of intracellular targets. ISG15 is a member of a small group of function-specific ubiquitin-like proteins that includes SUMO-1 and Nedd8. The conjugation of ISG15 to intracellular targets functions to regulate protein-protein interactions, in one instance acting in trans to mediate association of the target with intermediate filament.