OST1‐mediated BTF3L phosphorylation positively regulates CBFs during plant cold responses (EMBO J)

Ding et al. have just elucidated an important protein involved in the cold response of plants: BTF3L (basic transcription factor 3-like). The CBF/DREB (C-repeat binding factor/dehydration-responsive element protein) family of transcription factors are the main cold responsive pathway. The new article shows that BTF3L stabilizes CBF/DREB proteins. BTF3L is a beta subunit of the nascent polypeptide-associated complex which reversibly associates with ribosomes to stabilize generating peptides. Using a combination of in vitro and in vivo methods, the authors showed that OST1 (OPEN STOMATA 1, a kinase involved in activation of CBF/DREBs) interacts with and phosphorylates BTF3L during cold stress. This phosphorylation enhances, but is not required for, BTF3L binding and stabilization of CBF/DREB1 proteins. Until this point, most research on CBF/DREB transcription factors has taken place at the transcriptional level which makes identifying a post-translational stabilization of these proteins an important piece of the puzzle. This discovery continues to unravel cold regulation in plants and provides additional targets for investigations of non-model cold intolerant plant species.  (Summary by Jennifer Robison) EMBO J. 10.15252/embj.201798228