Abstract
To understand the G-protein related signal transduction system of plant in detail, we tried to obtain various controlling factors influencing on the function of G-protein α subunit in vivo. For this, we designed the efficient vector system, having the TAP tag cassette for isolating the highly purified protein complex and fused with GFP not only to localize the protein but to screen the transformants rapidly with the western blot. Moreover, we used Arabidopsis sgs mutant as a host, not to reject the foreign gene introduction. To test the capability of newly constructed vector, we coexpressed GPA1 with a marker protein, H+-ATPase into the Arabidopsis protoplasts. Result showed that the two proteins were observed at the plasma membrane with the fluorescence microscope. After isolation of the GPA1-interacting proteins by this vector system, they were analyzed by MALDI-TOF Mass Spectrometry. Now, we examine the role of individual proteins in the signal network.
