Abstract
Blue light receptor phototropin (phot) is involved in various light responses, such as phototropism, chloroplast movement, and stomatal opening, in plants. Phot is chromoprotein consisting of the N-terminal LOV domain and the C-terminal kinase domain. Although phots have been discovered in various plants, detailed molecular mechanism of their action including the interaction factor remains unknown.
To clarify the mechanism of phot signal transduction, we attempted to express a phot2:GFP fusion protein (P2G) in transgenic Arabidopsis and isolate a factor(s) that interacts with phot. P2G localized strongly to the plasma membrane in the dark. Upon Illumination with Blue light, it associated to the Golgi apparatus and the kinase domain was responsible for the Golgi apparatus localization. A series of yeast two-hybrid screenings allowed us to obtain an ADP-ribosylation factor 1 (ARF1) which regulates vesicular trafficking.
In this session, we discuss the molecular mechanism of blue light signal transduction.
