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A cell‐free system for light‐dependent nuclear import of phytochrome
Author(s) -
Pfeiffer Anne,
Kunkel Tim,
Hiltbrunner Andreas,
Neuhaus Gunther,
Wolf Iris,
Speth Volker,
Adam Eva,
Nagy Ferenc,
Schäfer Eberhard
Publication year - 2009
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/j.1365-313x.2008.03721.x
Subject(s) - acetabularia , phytochrome , hypocotyl , nuclear transport , phytochrome a , microbiology and biotechnology , arabidopsis thaliana , biology , nucleus , cytosol , biophysics , botany , cell nucleus , biochemistry , gene , red light , mutant , enzyme
Summary 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.