A plant gene switch moves in the light to the nucleus

The model: red light activates the plant photoreceptor phytochrome, that will in turn trigger the gene switch CPRF2 to move into the nucleus and to switch on light-activated genes.

Kircher S, Wellmer F, Nick P, Rügner A, Schäfer E, Harter K (1999) Nuclear Import of the Parsley bZIP Transcription Factor CPRF2 Is Regulated by Phytochrome Photoreceptors. J Cell Biol 144, 201-211 (85 quotations, state 27.09.2010) - pdf

What is the finding? Signals are mostly transduced by second messengers from the membrane into the nucleus, where they control the activity of transcription factors. The glucocorticoid receptor is a classical example for a different pathway, whereby the receptor itself migrates into the nucleus. The same principle has also been shown for the plant photoreceptor phytochrome. In this work we demonstrate that the transcription factor CPRF2 (common plant regulatory factor 2) moves into the nucleus upon irradiation with red light. This nuclear transport can be switched off by subsequent far-red light, which is a strong evidence for a control through phytochromes. This is also shown by transcription assays in-vitro, but mainly by cell biological approaches, where the nuclear transport of CPRF2 is shown by immunofluorescence.