White Collar-1, a Circadian Blue Light Photoreceptor, Binding to the Frequency Promoter

• Published in: Science (American Association for the Advancement of Science) Vol. 297; no. 5582; pp. 815 - 819
• Main Authors: Froehlich, Allan C., Liu, Yi, Loros, Jennifer J., Dunlap, Jay C.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 02.08.2002; The American Association for the Advancement of Science
• Subjects: Biological and medical sciences; Circadian rhythm; Circadian Rhythm - radiation effects; Circadian rhythms; Color; DNA; DNA probes; DNA, Fungal - genetics; DNA, Fungal - metabolism; DNA-Binding Proteins - metabolism; Dose response relationship; Flavin Mononucleotide - metabolism; Flavin-Adenine Dinucleotide - metabolism; Fundamental and applied biological sciences. Psychology; Fungal Proteins - genetics; Fungal Proteins - metabolism; Fungi; Gels; Gene Deletion; Gene Expression Regulation, Fungal - radiation effects; Light; Logical Thinking; Microbiology; Miscellaneous; Mycology; Neurospora; Neurospora crassa - genetics; Neurospora crassa - metabolism; Neurospora crassa - radiation effects; Photophobia; Photoreceptors; Photoreceptors, Microbial - metabolism; Promoter regions; Promoter Regions, Genetic - genetics; Protein Binding; Response Elements - genetics; RNA, Fungal - genetics; RNA, Fungal - metabolism; Signal Transduction; Transcription Factors - metabolism; Transcriptional Activation - radiation effects; Transcripts (Written Records); Visible spectrum; Wavelengths; United States; Fungi; Transcription promoter; Photoreceptor; Ascomycetes; Neurospora crassa; Biological rhythm; Blue light; Circadian rhythm; Thallophyta
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1073681

In the fungus Neurospora crassa, the blue light photoreceptor(s) and signaling pathway(s) have not been identified. We examined light signaling by exploiting the light sensitivity of the Neurospora biological clock, specifically the rapid induction by light of the clock component frequency (frq). Light induction of frq is transcriptionally controlled and requires two cis-acting elements (LREs) in the frq promoter. Both LREs are bound by a White Collar-1 (WC-1)/White Collar-2 (WC-2)-containing complex (WCC), and light causes decreased mobility of the WCC bound to the LREs. The use of in vitro-translated WC-1 and WC-2 confirmed that WC-1, with flavin adenine dinucleotide as a cofactor, is the blue light photoreceptor that mediates light input to the circadian system through direct binding (with WC-2) to the frq promoter.