Precision Tuning of ABA Signaling by Ubiquitination of ABA Receptors: Modulating Protein Activity and Localization.

Abstract

Ubiquitination, a form of post-translational modification, precisely orchestrates plant hormone signaling by modulating protein activity, localization, assembly, and interaction. The RING-type E3 ubiquitin ligase RSL1 and the CUL4-DDB1-DWD-type E3 ubiquitin ligase complex promote the degradation of ABA receptors by mediating their polyubiquitination. In contrast, Arabidopsis DOA10A, an E3 ubiquitin ligase associated with ERAD, enhances the localization of ABA receptors to the plasma membrane through mono-ubiquitination, thereby improving their function in signal perception. Different mechanisms mediating polyubiquitination or monoubiquitination play a decisive role in determining the fate of ABA receptors.