Light-Induced Dynamic Change of Phytochrome B and Cryptochrome 1 Stabilizes SINATs in .

Ubiquitin-dependent protein degradation plays an important role in many plant developmental processes. We previously identified a class of SINA RING-type E3 ligases of (SINATs), whose protein levels decrease in the dark and increase in red and blue light, but the underlying mechanism is unclear. In this study, we created transgenic lines carrying point mutations in genes and photoreceptors-NLS or -NES transgenic plants to investigate the regulatory mechanism of SINAT protein stability.

SINAT E3 Ligases Control the Light-Mediated Stability of the Brassinosteroid-Activated Transcription Factor BES1 in Arabidopsis.

The plant hormones brassinosteroids (BRs) participate in light-mediated regulation of plant growth, although the underlying mechanisms are far from being fully understood. In addition, the function of the core transcription factor in the BR signaling pathway, BRI1-EMS-SUPPRESSOR 1 (BES1), largely depends on its phosphorylation status and its protein stability, but the regulation of BES1 is not well understood. Here, we report that SINA of Arabidopsis thaliana (SINATs) specifically interact with dephosphorylated BES1 and mediate its ubiquitination and degradation.