A kinase for light and time

Abstract

The eukaryotic filamentous fungus Neurospora crassa has proven to be a dependable model system for the analysis of light-regulated gene expression and circadian rhythmicity. The molecular basis of the core circadian clock is a transcription/translation-based feedback loop in which a heterodimer of the white-collar 1 (WC-1) and white-collar 2 (WC-2) proteins act as a transcription factor to promote expression of the negative elements in the clock, frq mRNA and FRQ protein. Additionally, WC-1 is a flavoprotein that acts as the primary responder to environmental light and, in conjunction with WC-2, is the major photoreceptor for the clock as well as other light-regulated processes. Protein kinase C acts as a light-dependent regulator of the WC-1 protein. © 2005 Blackwell Publishing Ltd.