Source:
Generated By: https://synbiohub.org/public/igem/igem2sbol/1
Created by: Emilie Gounin
Date created: 2016-10-12 11:00:00
Date modified: 2016-10-13 06:15:26
White collar-1 (WC-1) - photoreceptor in Neurospora tetrasperma
| Types | DnaRegion |
| Roles | CDS Coding |
| Sequences | BBa_K1935003_sequence (Version 1) |
Description
White Collar-1 (wc-1) is a gene in Neurospora tetrasperma encoding the protein WC-1. WC-1 has two separate roles in the cell. First, it is the primary photoreceptor for Neurospora and the founding member of the class of principle blue light photoreceptors in all of the fungi. Second, it is necessary for regulating circadian rhythms in FRQ. It is a key component of a circadian molecular pathway that regulates many behavioral activities, including conidiation. WC-1 and WC-2, an interacting partner of WC-1, comprise the White Collar Complex (WCC) that is involved in the Neurospora circadian clock. WCC is a complex of nuclear transcription factor proteins, and contains transcriptional activation domains, PAS domains, and zinc finger DNA-binding domains. WC-1 and WC-2 heterodimerize through their PAS domains to form the White Collar Complex.Photoreception: WC-1 has been shown to be a blue-light photoreceptor, and is a necessary component of the Neurospora light-induced response pathway. In functional Neurospora, the WC-1 LOV domain binds to the flavin adenine dinucleotide (FAD) chromophore, which is responsible for the conversion of light to mechanical energy. FAD displays maximum absorption of light at 450nm, thus explaining WC-1's maximal sensitivity to blue light.
Circadian regulation: WCC acts as a positive element in the circadian clock. It serves as an activator of frq gene transcription by binding to two DNA promotor elements in the nucleus: the Clock box (C box) and the Proximal Light-Response Element (PLRE). PLRE is required for maximal light induction, while the C box is required for both maximal light induction and maintaining circadian rhythmicity in constant darkness.
In addition, light-activated WCC is shown to induce the transcription of VIVID, a small flavin-binding blue-light photoreceptor that is required for adaptation to light-induced responses in the transcription of light-induced genes, including wc-1 and frq. VIVID is a negative regulator of light responses, although its mechanism is not yet known.
Only wc-1 is required for transient light-induction, but both wc-1 and wc-2 are required for the circadian clock to run. Because the core of the clock is based on a rhythmic expression of frq, the acute light-induction pathway provides a direct way to reset the clock.