GSK3 regulates VRN1 to control flowering time in wheat.

We tested whether VRN1 is a substrate of GSK3 phosphorylation by performing I in vitro i VRN1 phosphorylation assays using equivalent amounts of GSK3 or gsk3 proteins. To further test whether GSK3 regulates VRN1 protein abundance, we performed a cell-free protein degradation assay to monitor the contents of GST-VRN1 in the absence or presence of the 26S proteasome inhibitor MG132. GLYCOGEN SYNTHASE KINASE 3 physically interacts with VRN1 and regulates its accumulation to mediate flowering in wheat. [Extracted from the article]