The long term goal of this research is to understand the pathway of protein import into the chloroplast, and to elucidate at the molecular level the components involved and how they function. The chloroplast is the site of photosynthesis and it also carries out an amazing array of biosynthetic reactions. It participates in the synthesis of fatty acids, essential aromatic amino acids, plant hormones, tetrapyrroles, terpenoids, as well as being required for nitrogen and sulfur reduction. The biogenesis of the chloroplast depends on the correct targeting and transport of nuclear-encoded proteins from the cytoplasm. It is predicted that the genome of the model plant Arabidopsis thaliana codes for ~2500 different precursor proteins which are targeted to the chloroplast for its biogenesis. This project will employ a genetic strategy to explore the chloroplast import pathway in Arabidopsis, complementing biochemical studies in the field. As a first step in this investigation, a chloroplast import deficient (cid4) mutant will be characterized. It is predicted that new steps and components will be identified that will broaden the current understanding of what determines the regulation and specificity of import. Results from these studies should be broadly applicable to other plants systems, and contribute to the understanding of protein sorting and trafficking in a eukaryotic cell.
Broader research impact The research will provide fundamental training for postdoctoral research associates and graduate students in plant science, molecular and cell biology and biochemistry who are the next generation of scientists in both academia and industry. Undergraduates, through work-study, minority, and honors'' student programs at The University of Chicago, will have the opportunity to join a research environment that may have a significant impact on their development, directing them to pursue a career in science, one of the educational goals of NSF. High school students will be recruited to participate in the summer Research in Biological Sciences Program, under the mentorship of the principal investigator. These studies will strengthen the infrastructure of science that depends on an understanding of the mechanisms of fundamental cellular processes, and with that knowledge, contribute to progress in the agricultural, industrial and pharmaceutical enterprises of society.
