OTUB1 (also known as otubain-1) is a deubiquitinating enzyme that belongs to the OTU family of cysteine proteases []. OTUB1 can specifically remove 'Lys-48'-linked conjugated ubiquitin from proteins and plays an important regulatory role at the level of protein turnover by preventing degradation []. It also plays a key non-catalytic role in DNA repair regulation by inhibiting activity of RNF168, an E3 ubiquitin-protein ligase that promotes accumulation of 'Lys-63'-linked histone H2A and H2AX at DNA damage sites [, ]. Mutations in OTUB1 cause tumour predisposition syndrome (TPDS), characterised by predisposition to develop a variety of tumours [].
