The effort has provided valuable insights into endocytosis, which is involved in a number of cellular functions with a bearing on human physiology and disease, such as cholesterol metabolism, neurotransmitter signalling and viral infection. The hope is that the work could lead to new drug targets, for example ways of inhibiting viral diseases by preventing them from being taken up by host cells.
Two scientific papers, published in the scientific journal Nature yesterday, describe how researchers used the RNA interference screening approach to identify 210 different human kinases that are involved in endocytosis in what is claimed to be the largest published RNAi screen using a siRNA library to date.
The papers were authored by a group at the Max Planck Institute for Molecular Cell Biology and Genetics (MPI-CBG) in Dresden, Germany. The team used the Ambion Silencer Kinase siRNA Library to perform the screen.
In an RNAi screen, the expression of individual genes is systematically reduced by introduction of double-stranded RNA molecules, and then the resulting effects on cells are measured. Ambion's library of siRNAs can individually reduce gene expression of all of the human kinases.
Marino Zerial, director of the MPI-CBG, said that this is one of the first papers to use siRNAs targeting an entire class of genes to explore how they coordinate two endocytic mechanisms in response to different signaling pathways.
"This work demonstrates how high content assays coupled to RNAi-based genome-wide screens can provide novel mechanistic insights as well as unexpected opportunities for drug development," he commented.
"Over the last 3 years, RNA interference has revolutionised functional genomics research, and this work illustrates the power of the approach," commented Matt Winkler, Ambion's chief executive and chief scientific officer.
The library is a key tool in the elucidation of the kinome - the pattern of kinase enzymes that form an inter-related network of cell-controlling pathways.
Kinase pathways play an essential role in signal transduction and the control of metabolism, transcription, apoptosis and differentiation. As a result, the enzymes have been implicated in a number of diseases processes such as cancer, inflammation and diabetes. Over 500 different kinases have been identified, representing approximately 1.7 per cent of all human genes.