Phytochrome: A serine kinase illuminates the nucleus!

Abstract

Plants detect ambient light environment for their optimal growth and survival using a battery of photoreceptors, of which phytochrome is the most prominent. Phytochrome acts as a serine kinase and can autophosphorylate itself or transphosphorylate its partner proteins. The exposure of light to plants triggers translocation of phytochrome from the cytosol to the nucleus where it interacts with several proteins, including transcriptional factors. It is now believed that many photoresponses in plants may be mediated by direct regulation of transcription by phytochrome in conjunction with transcription factors.