Establishment of Photosynthesis, a Tale of Two Genomes

The function of the eukaryotic cell depends on regulated and reciprocal interaction between its different compartments. This includes not only the exchange of metabolic intermediates and energy equivalents but also information.

The presence of genes encoding organellar proteins in different cellular compartments necessitates a tight coordination of expression from the different genomes.

In the proposed project I will take an integrative approach using a combination of genetics, molecular biology, biochemistry and cell biology to investigate the interaction between the chloroplasts and the nucleus through the process of chloroplast development and the establishment of photosynthetic metabolism.

My project is divided into the following three sub projects describing the events in the three cellular compartments driving the establishment of photosynthesis; 1) Determine the mechanism behind the regulation of the repressive GUN1-mediated retrograde signal in the plastids. 2) Determine how this retrograde signal is transduced from the plastids through the cytosol to the nucleus to control photosynthetic gene expression. 3) Identify the nuclear regulatory component(s) such as transcription factors or chromatin re-modellers responsible for the major chromatin changes associated with the increase in nuclear photosynthetic gene expression in response to loss of the repressive GUN1-mediated retrograde signal.