Abstract
Blue light receptor phototropin (phot) is involved in various light responses, such as phototropism, chloroplast movement, and stomata opening, in plants. Phot is chromoprotein consisting of the N-terminal chromo 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.
In order to clarify the mechanism of phot signal transduction, we attempted to isolate a factor(s) that interacts with phot. A series of yeast two-hybrid screenings allowed us to obtain four novel genes. One of them is a homologue of ADP-ribosylation factor 1 (Arf1) which regulates vesicular trafficking. Moreover, we show that phot specifically interacts with the GTP-bound form of Arf1 and the Ser/Thr kinase domain of phot is involved in the interaction. In this session, we discuss the general molecule mechanism of blue light signal transduction while reporting a detailed result.
