Expression of Chlamydomonas actin-gfp fusion gene in tobacco suspension cell and polymerization of the actin-gfp protein in vitro

The fusion gene of actin (cDNA of Chlamydomonas reinhardtii) and green fluo rescence protein (gfp) had been constructed into two expression vectors whi ch could be expressed in E. coli and tobacco suspension cells BY2. The corr ect expression was observed in E. coli and BY2 with a fluorescence microsco py, The fusion protein, which took part in the membrane skeleton, was mainl y located peripherally along the membrane, specially the fusion protein was distributed around nucleus and cell plate, while the fusion protein also f orms F-actin in the cell. The fusion protein was purified from Bl21plus by ammonium sulfate fractionation, ion exchange chromatography and hydrophobic interaction chromatography. The purified production could polymerize into F-actin when the actin polymerizing buffer was added. It was demonstrated t hat the characteristics and function of actin in Chlamydomonas was similar with those of animals and higher plants.