| Abstract Detail
Photomorphogenesis Sharrock, Bob [1], Clack, Ted [2], Liu, Peng [2]. Structure and activity of phytochrome heterodimers in Arabidopsis. The Arabidopsis genome encodes five phytochrome apoproteins, which assemble with a bilin chromophore to produce red/far-red sensing photoreceptors. These phy holoproteins fall into two functionally distinct groups: type I phyA, which senses very low levels of light and continuous FR, and type II phyB-phyE, which sense long term R and the ratio of R:FR. We have used yeast two-hybrid analysis and co-immunoprecipitation experiments to investigate the binding interactions of these proteins. The phyA, phyB, and phyD C-terminal domains show positive yeast two hybrid interaction with themselves, as predicted for homodimerization, whereas the phyC and phyE C-termini do not. PhyB, phyD, and phyE also bind in heteromeric combinations with at least one other type II phytochrome in this assay. All five epitope-tagged apoproteins were constructed and shown to produce biologically active phytochromes in transgenic plants by complementation of mutant phenotypes and over-expression phenotypes. Co-immunoprecipitation assays utilizing the tagged phytochromes demonstrate that several heterodimeric combinations of the type II phyB-phyE proteins assemble in vivo. These results suggest that the repertoire of phytochrome forms in higher plants is more diverse than previously thought. Log in to add this item to your schedule
1 - Montana State University, Department of Plant Sciences and Plant Pathology, 119 Plant Biology Building, Bozeman, MT, 59717-3150, USA 2 - Montana State University, Department of Plant Sciences and Plant Pathology
Keywords: none specified
Presentation Type: Plant Biology Abstract Session: P Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton Date: Sunday, July 8th, 2007 Time: 8:00 AM Number: P31013 Abstract ID:1005 |