Hydroxylation as a mechanism for regulating the deubiquitinating enzyme OTUB1 (360G-Wellcome-202204_Z_16_Z)

The hypoxic response is an evolutionary conserved mechanism that allows cells to survive low oxygen levels, by promoting activation of genes that regulate metabolism, angiogenesis, redox homeostasis and immunity. Central to this pathway are the hypoxia inducible transcription factors (HIFs) that are regulated by hydroxylase enzymes that sense intracellular oxygen levels and modify HIF activity. The role of these hydroxylase enzymes outside of the HIF pathway was unclear, but we have recently shown that the asparagine hydroxylase, factor inhibiting HIF (FIH), modifies the deubiquitinating enzyme, OTUB1, altering metabolic responses within the cell. However, how asparagine hydroxylation of OTUB1 regulates its enzymatic activity is not known. Therefore, in this project we will use an in vitro assay that we have established to determine how asparagine hydroxylation of OTUB1 regulates its deubiquitination activity and whether hydoxylation prevents binding to other ubiquitin enzymes. This vacation project offers an excellent introduction to protein biochemistry in an area of important scientific interest, and complements ongoing research within Dr Nathan’s laboratory.