title: Phytochrome-interacting factors.
abstract: The phytochrome family of sensory photoreceptors transduces environmental light signals to responsive nuclear genes by poorly defined pathways. The recent application of yeast two-hybrid library screens to the identification of components that physically interact with members of the phytochrome family has dramatically altered previous views of the likely intracellular signaling pathways. The evidence indicates that one pathway involves light-triggered translocation of the photoreceptor molecule from cytoplasm to nucleus where it binds specifically in its biologically active form to a promoter-bound basic helix-loop-helix protein. The phytochrome molecules are proposed to function as integral, light-switchable components of transcriptional regulator complexes targeting environmental light signals directly and instantly to specific gene promoters.
authors.affiliation: Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA. quail@nature.berkeley.edu
authors.forename: P H
authors.initials: PH
authors.lastname: Quail
mesh_terms: D029681:Arabidopsis Proteins; D051792:Basic Helix-Loop-Helix Proteins; D002352:Carrier Proteins / Q000378:metabolism; D056931:Cryptochromes; D029721:Drosophila Proteins; D005136:Eye Proteins; D005420:Flavoproteins / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D009701:Nucleoside-Diphosphate Kinase / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism; D017956:Photoreceptor Cells, Invertebrate; D010834:Phytochrome / Q000378:metabolism*; D010940:Plant Proteins / Q000378:metabolism*; D011485:Protein Binding; D043562:Receptors, G-Protein-Coupled; D015398:Signal Transduction
chemical_list: D029681:Arabidopsis Proteins; D051792:Basic Helix-Loop-Helix Proteins; D002352:Carrier Proteins; D056931:Cryptochromes; D029721:Drosophila Proteins; D005136:Eye Proteins; D005420:Flavoproteins; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D009701:Nucleoside-Diphosphate Kinase; D010750:Phosphoproteins; D010834:Phytochrome; D010940:Plant Proteins; D043562:Receptors, G-Protein-Coupled; C116162:PIF3 protein, Arabidopsis; C485609:PKS1 protein, Arabidopsis; C119522:PKS1 protein, plant; C119828:cry protein, Drosophila; C121988:nucleoside diphosphate kinase 2