Functional conservation of light, oxygen, or voltage domains in light sensing.
In Neurospora, the flavin adenine dinucleotide-containing protein WHITE COLLAR-1 is the blue-light photoreceptor for the circadian clock and other light responses. The putative chromophore-binding domain of WC-1, its light, oxygen, or voltage (LOV) domain, is similar to the LOV domains found in the plant phototropins, the Neurospora VIVID (VVD) protein, and the Arabidopsis FKF1 and its related proteins. Studies of the plant phototropins have identified 11 flavin-contacting residues that are also conserved in the LOV domains of WC-1, VVD, and FKF1. In this study, by mutating the putative WC-1 flavin-binding sites, we show that these sites are important for the light function of the protein, suggesting that the WC-1 LOV domain adapts a structure similar to that of the phototropin LOV domains. By creating a Neurospora strain in which the LOV domain of WC-1 is swapped with that of VVD, we show that the LOV domain of VVD partially replaces the function of the WC-1 LOV domain, suggesting that VVD is a wc-dependent photoreceptor in Neurospora. Furthermore, we show that the Neurosporastrains containing a chimeric WC-1 protein with the LOV domain from FKF1 or phot1 can also sense light, suggesting that FKF1 and its related proteins are light sensors in Arabidopsis. Taken together, our data suggest that these LOV domains are structurally similar protein modules involved in blue-light sensing.
Department of Physiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.
Ping
P
Cheng
Qiyang
Q
He
Yuhong
Y
Yang
Lixin
L
Wang
Yi
Y
Liu
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D001665:Binding Sites; D002940:Circadian Rhythm / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D005415:Flavins / Q000378:metabolism; D005656:Fungal Proteins; D008027:Light; D008969:Molecular Sequence Data; D009492:Neurospora crassa / Q000235:genetics; D010100:Oxygen / Q000378:metabolism*; D010957:Plasmids; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000502:physiology*
D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; C410504:FKF1 protein, Arabidopsis; D005415:Flavins; D005656:Fungal Proteins; D014157:Transcription Factors; C105589:wc-1 protein, Neurospora crassa; D010100:Oxygen