Andreas Marx / Martin Scheffner
Unnatural amino acids to study protein ubiquitylation
Depending on the type of ubiquitylation (e.g. mono- vs. poly-ubiquitylation), respectively modified proteins can have very different fates. To obtain insight into the mechanisms underlying this phenomenon, unnatural amino acids will be employed to synthesize differently linked ubiquitin chains. The respective chains will be used to isolate proteins which recognize different ubiquitin chains in a selective manner and are thus presumably involved in determining the fate of ubiquitylated proteins. Furthermore, unnatural amino acids will be used to prepare homogeneous populations of the tumor suppressor p53 that are site-specifically modified with (mono)ubiquitin or the ubiquitin-like proteins SUMO and NEDD8. The protein-protein interaction properties of the respectively modified p53 molecules will be studied.