Photoactivation of the cryptochrome/photolyase superfamily

Publication date: Available online 26 December 2014 Source:Journal of Photochemistry and Photobiology C: Photochemistry Reviews Author(s): Jing Wang , Xianli Du , Weisong Pan , Xiaojie Wang , Wenjian Wu The cryptochrome/photolyase superfamily is a class of flavoproteins that can regulate the growth and development in plants, as well as the circadian clock and the potential magnetic navigation in animals, primarily by absorbing UV-A and blue light. It is generally agreed that these functions depend on the photochemical reaction of the flavin adenine dinucleotide (FAD) chromophore, non-covalently binding to cryptochromes or photolyases. Irradiation can initiate either photoreduction between FAD and certain electron donors or electron jumping in FAD, thereby leading to the generation of intermediates that activate the protein. This signaling process is known as photoactivation. Subsequently, the activated protein will interact with downstream receptors to transfer the photo and magnetic signals. Based on in-depth research on photoactivation, two photo-cycle mechanisms for the photoreception/photosignaling of the cryptochrome/photolyase superfamily, i.e., the photolyase model and the phototropin model, have been proposed. There is no apparent alternative to the photo-cycle of cyclobutane pyrimidine dimer (CPD) or (6-4) photolyase following the photolyase model. However, the mechanism is not clear for the photoactivation of cryptochromes and CRY-DASH, a new subcategory of...
Source: Journal of Photochemistry and Photobiology C: Photochemistry Reviews - Category: Chemistry Source Type: research