The Function of Deubiquitinating Enzymes in Arabidopsis: Recent Progress of Ubiquitin-Specific Proteases (UBPs)

Compared to transcriptional regulation, post-translational modification is more efficient for eliciting rapid responses to external stimuli in plants. Ubiquitination, as a representative post-translational modification in eukaryotes, regulates the half-life and activity of target proteins. Although studies on the ubiquitination process have been intensively conducted, focusing on the function of E3 ubiquitin ligases, the deubiquitination process mediated by deubiquitinases (DUBs) remains relatively poorly understood. DUBs, which counteract the actions of E3 ubiquitin ligases, are categorized into five families based on their catalytic domains. Among DUB families, the ubiquitin-binding protease (UBP) is the largest in plants. The UBP family in Arabidopsis (AtUBP) comprises 27 members, many of which have been implicated in cellular events. In this study, we summarized the most recent knowledge related to the structure and biological functions of AtUBP members. A detailed understanding of their biological roles and modes of action will provide new insights into the mechanisms regulating protein stability and activity via ubiquitination/deubiquitination in Arabidopsis.