Ubiquitination: a tool for plant adaptation to changing environments

Post-translational modifications namely ubiquitination, phosphorylation, methylation and acetylation play distinct roles in regulating the growth and development of plants. Among these, the ubiquitination regulates the abundance, activities, subcellular compartmentalization and trafficking of regulatory proteins involved in diverse developmental as well as stress-responsive processes. The ubiquitin–proteasome system (UPS) involves five essential components namely ubiquitin, ubiquitin-activating enzyme (E1), ubiquitin-conjugating enzyme (E2), ubiquitin ligase (E3) and the intact 26S proteasome. The E3 ubiquitin ligase is the major component of UPS that recognizes and tethers poly-ubiquitins on the target proteins. Owing to its specificity of substrate recognition, the E3 ubiquitin ligase contributes not only to the proteome plasticity of the cell but also regulates the plant’s response to environmental cues. In this context, the review summarizes the components involved in UPS and elaborates the role of E3 ubiquitin ligase in biotic and abiotic stress responses. © 2018, Archana Sharma Foundation of Calcutta.