mutant screen distinguishes between residues necessary for light-signal perception and signal transfer by phytochrome b突变界面区分残留物所必需的感知和信号传输光信号通过光敏色素b.pdfVIP

Mutant Screen Distinguishes between Residues Necessary for Light-Signal Perception and Signal Transfer by Phytochrome B 1,2,3. 1,4,5. 1 2,3 1 Yoshito Oka , Tomonao Matsushita , Nobuyoshi Mochizuki , Peter H. Quail , Akira Nagatani * 1 Department of Biology, Graduate School of Science, Kyoto University, Kyoto, Japan, 2 Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, California, United States of America, 3 Plant Gene Expression Center, U.S. Department of Agriculture, Albany, California, United States of America, 4 Graduate School of Agriculture, Kyushu University, Fukuoka, Japan, 5 Organization for the Promotion of Advanced Research, Kyushu University, Fukuoka, Japan Abstract The phytochromes (phyA to phyE) are a major plant photoreceptor family that regulate a diversity of developmental processes in response to light. The N-terminal 651–amino acid domain of phyB (N651), which binds an open tetrapyrrole chromophore, acts to perceive and transduce regulatory light signals in the cell nucleus. The N651 domain comprises several subdomains: the N-terminal extension, the Per/Arnt/Sim (PAS)-like subdomain (PLD), the cGMP phosphodiesterase/ adenyl cyclase/FhlA (GAF) subdomain, and the phytochrome (PHY) subdomain. To define functional roles for these subdomains, we mutagenized an Arabidopsis thaliana line expressing N651 fused in tandem to green fluorescent protein, b- glucuronidase, and a nuclear localization signal. A large-scale screen for long hypocotyl mutants identified 14 novel intragenic missense mutations in the N651 moiety. These new mutations, along with