539 / 2019-03-12 08:38:48

Proteasomal and non-proteasomal ubiquitination in plant stress signaling

ubiquitination,proteasome,ERAD tuning,endocytosis,autophagy

全体主题 > Abiotic Stress

Plants are frequently subjected to various stresses, such as drought and high salinity stresses during their life cycles, in which ABA, as a signal molecule, mediates plant tolerance. Ubiquitination of proteins is involved in many steps in ABA signaling pathway, from perception to action, which plays key roles in plant adaptation to drought stress. Ubiquitination requires the coordination of E2-ubiquitin conjugating enzyme and E3 ligase to act on diversity substrates. This work will report both proteasomal and non-proteasomal ubiquitination in plant stress signaling, mainly in salt stress signaling pathway in combination of stress related hormone pathway. We will focus on proteasomal ubiquitination, such as quality control mechanisms that allow misfolded or unassembled proteins to be retained in the endoplasmic reticulum (ER) and subsequently degraded by ER-associated degradation (ERAD). The ERAD pathway is well-studied in yeast and mammals; however, the biological functions of plant ERAD have not been reported. Through molecular and cellular biological approaches, we determined ERAD is necessary for plants to overcome salt stress. Upon salt treatment ubiquitinlated proteins increased in plant cells, especially unfolded proteins which quickly accumulated in the ER and subsequently induced ER stress responses. We will also discuss about those non-proteasomal ubiquitination, such as endocytosis and autophagy in stress signaling.