A novel function for translation initiation factor eIF5

点击翻译按钮获取中文摘要

Interactions between proteins modulate essential functions of cells ensuring that they can grow and perform their tasks at the correct time and place. Each protein within a cell is like a piece within a complex machine. In a machine each part must be in the correct place and act at the correct time in concert with the other parts for the machine to function properly. The same is true for proteins within cells, but unlike most machines and their parts, proteins are continually renewed, move and can be modified by interaction with many other cell components to alter their function and/or location. Many proteins act together within complexes composed of proteins or with other cell components (lipids, DNA or small molecules for example) to coordinate a common function. One group of proteins relevant to this proposal is required make (or synthesize) all new proteins in each cell. These are called 'protein synthesis factors'. Understanding how protein synthesis factors function and interact with each other is therefore fundamental to understanding how proteins are made in all cells in all organisms. By improving our understanding how processes such as protein synthesis work in normal cells it can help scientists understand diseases in which this process is altered, or how infectious agents such as viruses are able to hijack plant, animal or human cells and cause infectious diseases. In work leading up to this proposal we have identified a novel complex between two protein synthesis factors known as eIF2 and eIF5. This has lead to a hypothesis for the function of this complex which we intend to assess here using a combination of biochemical experiments with purified proteins 'in the test-tube' and genetic experiments using yeast cells as a model simple cell system to understand the biological significance of this interaction for the mechanism and regulation of protein synthesis.