title: White collar-1, a DNA binding transcription factor and a light sensor.
abstract: Blue light regulates many physiological processes in fungi, but their photoreceptors are not known. In Neurospora crassa, all light responses depend on the Per-Arnt-Sim (PAS) domain-containing transcription factor white collar-1 (wc-1). By removing the WC-1 light, oxygen, or voltage domain, a specialized PAS domain that binds flavin mononucleotide in plant phototropins, we show that light responses are abolished, including light entrainment of the circadian clock. However, the WC-1-mediated dark activation of frq remains normal in this mutant, and the circadian clock can be entrained by temperature. Furthermore, we demonstrate that the purified Neurospora WC-1-WC-2 protein complex is associated with stoichiometric amounts of the chromophore flavin-adenine dinucleotide. Together, these observations suggest that WC-1 is the blue-light photoreceptor for the circadian clock and other light responses in Neurospora.
authors.affiliation: Department of Physiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.
authors.forename: Qiyang
authors.initials: Q
authors.lastname: He
authors.forename: Ping
authors.initials: P
authors.lastname: Cheng
authors.forename: Yuhong
authors.initials: Y
authors.lastname: Yang
authors.forename: Lixing
authors.initials: L
authors.lastname: Wang
authors.forename: Kevin H
authors.initials: KH
authors.lastname: Gardner
authors.forename: Yi
authors.initials: Y
authors.lastname: Liu
mesh_terms: D000595:Amino Acid Sequence; D002940:Circadian Rhythm / Q000528:radiation effects; D003116:Color; D004271:DNA, Fungal / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D003624:Darkness; D019281:Dimerization; D005486:Flavin Mononucleotide / Q000378:metabolism; D005182:Flavin-Adenine Dinucleotide / Q000378:metabolism; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal / Q000528:radiation effects; D008027:Light; D008969:Molecular Sequence Data; D009492:Neurospora crassa / Q000235:genetics / Q000378:metabolism* / Q000528:radiation effects; D010100:Oxygen / Q000378:metabolism; D020283:Photoreceptors, Microbial / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D020218:Response Elements / Q000235:genetics; D013696:Temperature; D014157:Transcription Factors / Q000737:chemistry / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*
chemical_list: D004271:DNA, Fungal; D004268:DNA-Binding Proteins; C087405:FRQ protein, Neurospora crassa; D005656:Fungal Proteins; D020283:Photoreceptors, Microbial; D014157:Transcription Factors; C105589:wc-1 protein, Neurospora crassa; C103772:white collar 2 protein, Neurospora; D005182:Flavin-Adenine Dinucleotide; D005486:Flavin Mononucleotide; D010100:Oxygen