This proposal describes studies on cellular components that are involved in harvesting the energy of sunlight and making that energy useful for the production of sugars and carbohydrates in the cell. The organism being investigated is in the group of algae known as diatoms and is named Phaeodactylum tricornutum. Diatoms are very abundant in both marine and fresh water environments. In fact, these organisms may be responsible for as much as 20% of the total CO2 fixation on the earth. We have been studying both the structure of the light harvesting polypeptides of Phaeodactylum and the way in which they are targeted from the cytoplasm of the cell to their final location in the cell plastid, an extremely important organelle specialized to perform photosynthesis. By understanding how proteins can be specifically placed into different subcellular compartments like the plastid, we may be able to control both the constituents and the levels of specific constituents that are located in those compartments. This may prove very important in increasing the photosynthetic capabilities of organisms and ultimately in culturing these organisms in 'ocean field' (aquaculture) for the production of feed for livestock.
