摘要
Steroids function as signaling molecules in both animals and plants. While animal steroid hormones are perceived by nuclear receptor family of transcription factors, brassinosteroids （BR） in plants are perceived by a cell surface receptor kinase, BRI 1. Recent studies have demonstrated that BR binding to the extracellular domain of BRI 1 induces kinase activation and dimerization with another receptor kinase, BAKI. Activated BRI 1 or BAKI then regulate, possibly indirectly, the activities of BIN2 kinase and/or BSU 1 phosphatase, which directly regulate the phosphorylation status and nuclear accumulation of two homologous transcription factors, BZRI and BES 1. BZRI and BES 1 directly bind to promoters of BR responsive genes to regulate their expression. The BR signaling pathway has become a paradigm for both receptor kinase signaling in plants and steroid signaling by cell surface receptors in general.
基金
This work was supported in part by grants from National Natural Science Foundation of China(No.30328004,No.30571269)
National Institutes of Health(R01 GM66258-01).
