Fig. 2.

Scaffold proteins and their postulated role in ABA signaling. RACK1 recruits two substrate receptors for CUL4-based E3 ligases (DWA1 and DWA2) which function together to mediate the turnover of ABI5, thereby efficiently turning down ABA signaling downstream of the module of PYR/PYL/RCAR receptors, the PP2C-negative regulators- and the SnRK2-positive partners. Similarly, alterations modulating the ABI5 redox status include S-nitrosylation of specific Cys residues that enables the interaction to the E3 ubiquitin ligases KEG and CUL4 to promote ABI5 destabilization. Created with BioRender.com