Screening a human genome-wide siRNA library. (360G-Wellcome-079919_Z_06_Z)

The human genome contains ~22,000 genes, over half of which code for proteins of unknown function. The Cambridge Institute for Medical Research and the Hutchison/MRC Research Centre have recently joined the Genome-wide RNAi Global Initiative to screen the entire human genome using the first-ever genome-wide siRNA library. We will use the library to deplete each gene product in human tissue culture cells, then carry out plate-based assays, high throughput flow cytometry, and automated microscopy to examine the phenotype. We will assay for effects on endocytosis, secretion, organelle dynamics, autophagy, viral down regulation of immunoreceptors, cell motility, and mitosis. To carry out these experiments, we will need robotics, readout equipment, and a full-time "Librarian" who will oversee the distribution and screening of the library. We anticipate that many of the genes we identify as important in a particular pathway will turn out to participate in other pathways as well, so our screens should be complementary. By grouping together previously uncharacterised genes based on knockdown phenotype, we should begin to get a handle on protein interaction networks. Ultimately, we hope to find hundreds of new players, both in fundamental cellular pathways and in various disease states, and to learn how they function.