When proteins are synthesised in the cell, how do they know where to go?
24th October 1999 Gnter Blobel was awarded this years Nobel Prize for Physiology or Medicine for his discovery that proteins incorporate an address label as they are synthesised. The various compartments of a cell where different activities occur are delineated by membranes that are generally impermeable to proteins. Blobel proposed that newly-synthesised proteins carry targeting signals that direct them to the appropriate membrane and across it by way of specific channels into the compartment where the new proteins are required. Subsequent work has shown that this process occurs in all living species so far studied.
