Protein localization in proteomics.

A global analysis of the localization of 4156 yeast proteins has just been accomplished. Smaller scale analyses have been performed in a variety of organisms. These studies typically use green fluorescent protein as a tag for proteins in living cells. Improvements in the yellow and sapphire color variants will increase their utility. Reengineering of the red fluorescent protein has produced faster maturing tetrameric and monomeric variants not prone to aggregation. Techniques for high-throughput tagging of proteins include integration by homologous recombination, integration using mobile elements or recombinational cloning to produce plasmids expressing fusion proteins. Alternatives to localizing tagged proteins are to use antibodies or aptamers to detect the untagged protein.