Reciprocal Regulation of Protein Synthesis and Carbon Metabolism for Thylakoid Membrane Biogenesis
Functional duality of the pyruvate dehydrogenase complex
Metabolic control of gene expression coordinates the levels of specific gene products to meet cellular demand for their activities. This control can be exerted by metabolites acting as regulatory signals on a class of metabolic enzymes with dual functions as regulators of gene expression. However, little is known about how metabolic signals affect the balance between enzymatic and regulatory roles of these proteins. Here, we report an example of a protein with dual functions in gene expression and carbon metabolism. The chloroplast pyruvate dehydrogenase complex is well-known to produce activated di-carbon precursors for fatty acid, which is required for lipid synthesis. Our results show that a subunit of this enzyme forms ribonucleoprotein particles and influences chloroplast mRNA translation. Conversely, RNA binding affects pyruvate dehydrogenase (metabolic) activity. These findings offer insight into how intracellular metabolic signaling and gene expression are reciprocally regulated during membrane biogenesis. In addition, our results suggest that these dual roles of the protein might exist in evolutionary distant organisms ranging from cyanobacteria to humans.
source: PLoS Biology
Bohne A-V, Schwarz C, Schottkowski M, Lidschreiber M, Piotrowski M, et al. (2013) Reciprocal Regulation of Protein Synthesis and Carbon Metabolism for Thylakoid Membrane Biogenesis. PLoS Biol 11(2): e1001482. doi:10.1371/journal.pbio.1001482