Protein acetylation in regulation of photosynthesis
Photosynthetic reactions capture the energy of sunlight into chemical form. We aim at resolving how acetylation of chloroplast proteins affect light harvesting, quenching of excitation energy, photosynthetic electron transfer and organization of photosynthetic machinery. Recently, we have specifically focused on the identification and characterization of chloroplast acetyltransferases and studied their effects on the dynamics of photosynthetic processes.
The chloroplasts of higher plants perform oxygenic photosynthesis, which captures light energy into chemical form and thus is the basis of life on Earth. To ensure efficient primary production under a wide spectrum of environmental conditions, the structure and function of photosynthetic machinery must be extremely dynamic. The molecular mechanisms behind these dynamic changes remain largely uncharacterized, although detailed knowledge of these reactions is of utmost importance for understanding, improving and utilizing plant metabolism to benefit the humankind.
Chloroplast proteins are targets of various post-translational modifications. We have recently identified and characterized a family of chloroplast acetyltransferase enzymes (chloroplast GNAT family), which form a unique group of enzymes capable of catalyzing both N-terminal and lysine acetylation of proteins. One of the GNAT enzymes, GNAT2, has a crucial role in determining the dynamics of light harvesting, and it also affects thylakoid macro-organization and accumulation of various important metabolites. However, the detailed molecular mechanisms of these processes still require further studies. We are currently studying the impact of protein acetylation e.g. on the structure and assembly of photosynthetic pigment-protein complexes, plant lipid metabolism and plant stress responses in plants and cyanobacteria. We are also interested in the role of the GNAT enzymes in acetylation of metabolites and thereby in cell-to-cell signaling. We apply molecular biology, transcriptomics, protein biochemistry, proteomics, biophysics and physiology to answer these questions together with our wide network of national and international collaborators.
Oxygenic photosynthesis, producing carbohydrates and oxygen, is the basis of life on Earth. The success to apply photosynthesis in production of sustainable and carbon neutral energy as well as in production of maximal yields for food and feed supplies depends on the thorough understanding of photosynthetic reactions, especially the mechanisms regulating photosynthetic efficiency under changing environmental conditions.