Editors' ChoicePlant biology

Degrading in the light

Science's STKE  28 Sep 1999:
Vol. 1999, Issue 1, pp. tw1
DOI: 10.1126/stke.1999.1.tw1

Like animals, bacteria, and chlorophyll-containing plants, the filamentous fungus Neurospora crassa also responds to light. White collar-1 (WC-1) and white collar 2 (WC-2) are transcription factors that maintain the circadian cycle of Neurospora and regulate expression of light-induced genes. However, it is not clear how their activity is regulated by light. Talora et al. report that under dark or light conditions, these WC proteins form a complex in vivo. However, upon exposure to light, WC-1 becomes hyperphosphorylated, a modification that then triggers its release from the WC complex and its subsequent degradation. Newly synthesized WC-1 then takes its place. This observation suggests that transcription factor turnover is one mechanism by which gene expression is regulated by light.

Talora, C., Franchi, L., Linden, H., Ballario, P., Macino, G. (1999) Role of a white collar-1--white collar-2 complex in blue-light signal transduction. EMBO J. 18: 4961-4968. [Abstract] [Full Text]