Abstract
Ubiquitination, the reversible protein conjugation with ubiquitin (Ub), is a post-translational modification that enables rapid and specific cellular responses to stimuli without requirement of de novo protein synthesis. Although ubiquitination also displays non-proteolytic functions, it often acts as a signal for selective protein degradation through the ubiquitin-proteasome system (UPS). In plants, it has become increasingly apparent that the UPS is a central regulator of many key cellular and physiological processes, including responses to biotic and abiotic stresses. In the nucleus, protein regulation via the UPS orchestrates gene expression, genome maintenance, and signal transduction. Here, we focus on E3 Ub-ligase proteins as major components of the ubiquitination cascade that confer specificity of substrate recognition. We provide an overview on how they contribute to nuclear proteome plasticity during plant responses to environmental stress signals.
Highlights
Modulation of protein activity by post-translational modifications (PTMs) enables rapid and specific cellular responses to stimuli without the requirement of energy-consuming de novo protein synthesis
E3 Ub-ligases can be classified into four main subfamilies [Homologous to E6-associated protein Carboxyl Terminus (HECT), Really Interesting New Gene (RING), U-box, and Cullin-RING ligases (CRLs)], depending on their subunit composition and mode of action (Vierstra, 2009)
We previously identified the RING-type E3 Ub-ligase MIEL1 as being able to interact with the Arabidopsis defense-activating transcription factors (TFs) MYB30
Summary
Modulation of protein activity by post-translational modifications (PTMs) enables rapid and specific cellular responses to stimuli without the requirement of energy-consuming de novo protein synthesis. Ubiquitination regulates a plethora of cellular functions, from growth and development to responses to biotic and abiotic stimuli (Moon, 2004; Vierstra, 2009) This PTM involves the covalent attachment of one or more ubiquitin (Ub) proteins to a Lys (K) residue within specific target proteins through a stepwise cascade involving three enzymes: E1 (Ub-activating), E2 (Ub-conjugating), and E3 (Ub-ligase) (Vierstra, 2009). The E3 Ub-ligase PUB10 interacts with and ubiquitinates MYC2 in the nucleus, targeting MYC2 for proteasomal degradation (Jung et al, 2015) The importance of this regulatory mode has been underlined in a recent report showing that polyubiquitinated MYC2 is deubiquitinated by nuclear UBIQUITIN PROTEASE12 (UBP12) and UBP13, counteracting PUB10 activity (Jeong et al, 2017). EIRP1mediated proteasomal degradation of VpWRKY11 results in TABLE 1 | Plant E3-Ub ligases with known nuclear targets and their function
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
