IDENTIFICATION OF IN VIVO PHOSPHORYLATED PROTEINS IN THYLAKOID MEMBRANES OF ARABIDOPSIS THALIANA BY ELECTROSPRAY IONIZATION MASS SPECTROMETRY

摘要

Protein phosphorylation plays a major regulatory role in all cellular functions including photosynthesis. A unique light- and redox-controlled protein phosphorylation system has been evolved in plant thylakoid membranes for regulation of the photosynthetlc processes, like balancing the distribution of absorbed light energy between the two photosystems and control of protein maintenance and turnover. Identification of the sites of protein phosphorylation is necessary for understanding the regulatory mechanisms in photosynthesis, but it is experimentally challenging. We have developed dedicated mass spectrometric techniques for characterization of in vivo protein phosphorylation in the thylakoid membranes, which exclude the use of radioactive phosphate and antibodies against phosphoproteins.