Stable-isotope labeling with amino acids in nematodes

A method for performing quantitative proteomics experiments in Caenorhabditis elegans using stable-isotope labeling with amino acids in cell culture (SILAC) is described. The authors used the method to identify heat shock–responsive proteins in worms. Also in this issue, Fredens et al . describe a very similar method. We describe an approach for accurate quantitation of global protein dynamics in Caenorhabditis elegans. We adapted stable-isotope labeling with amino acids in cell culture (SILAC) for nematodes by feeding worms a heavy lysine– and heavy arginine–labeled Escherichia coli strain and report a genetic solution to elminate the problem of arginine-to-proline conversion. Combining our approach with quantitative proteomics methods, we characterized the heat-shock response in worms.