A cell-free system for light-dependent nuclear import of phytochrome

Anne Pfeiffer, Tim Kunkel, Andreas Hiltbrunner, Gunther Neuhaus, Iris Wolf, Volker Speth, Eva Adam, Ferenc Nagy, Eberhard Schäfer

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23 Citations (Scopus)


Translocation from the cytosol to the nucleus is an essential step in phytochrome (phy) signal transduction. In the case of phytochrome A (phyA), this step occurs with the help of FHY1 (far-red-elongated hypocotyl 1), a specific transport protein. To investigate the components involved in phyA transport, we used a cell-free system that facilitates the controlled addition of transport factors. For this purpose, we isolated nuclei from the unicellular green algae Acetabularia acetabulum. These nuclei are up to 100 μm in diameter and allow easy detection of imported proteins. Experiments with isolated nuclei of Acetabularia showed that FHY1 is sufficient for phyA transport. The reconstituted system demonstrates all the characteristics of phytochrome transport in Arabidopsis thaliana. In addition, FHY1 was also actively exported from the nucleus, consistent with its role as a shuttle protein in plants. Therefore, we believe that isolated Acetabularia nuclei may be used as a general tool to study nuclear transport of plant proteins.

Original languageEnglish
Pages (from-to)680-689
Number of pages10
JournalPlant Journal
Issue number4
Publication statusPublished - Feb 1 2009



  • Acetabularia
  • Cell free system
  • Nucleus
  • Phytochrome
  • Transport

ASJC Scopus subject areas

  • Genetics
  • Plant Science
  • Cell Biology

Cite this

Pfeiffer, A., Kunkel, T., Hiltbrunner, A., Neuhaus, G., Wolf, I., Speth, V., Adam, E., Nagy, F., & Schäfer, E. (2009). A cell-free system for light-dependent nuclear import of phytochrome. Plant Journal, 57(4), 680-689. https://doi.org/10.1111/j.1365-313X.2008.03721.x