2014/04/30
Ubiquitin profiling in liver using a transgenic mouse with biotinylated ubiquitin
Ubiquitination is behind most cellular processes, with ubiquitin substrates being regulated variously according to the number of covalently conjugated ubiquitin molecules and type of chain formed. Researchers from CIC bioGUNE, led by the group of Ikerbasque Research Professor Ugo Mayor have now created a transgenic mouse for ubiquitin proteomics that allows for the first time direct validation of the MS-identified proteins in a mammalian system. This has been achieved by expressing biotinylated ubiquitin and its use has been demonstrated for the isolation of ubiquitinated proteins from liver. The specificity and strength of the biotin-avidin interaction allow very stringent washes so only proteins conjugated to ubiquitin are isolated. In contrast to recently available antibody-based approaches, this strategy allows direct validation by immunoblotting, therefore revealing the type of ubiquitin chains (mono or poly) formed in vivo. Furthermore, this strategy allows the identification of candidate cysteine-ubiquitinated proteins, providing a strategy to identify those in a proteomic scale. This novel in vivo system will allow broad access to tissue-specific ubiquitomes and is now being combined with established liver disease models to investigate ubiquitin-dependent therapeutical approaches.
This study was recently published in Journal of Proteome Research:
Benoit Lectez , Rebekka Migotti , So Young Lee , Juanma Ramirez , Naiara Beraza , Bill Mansfield , James Sutherland , María Luz Martínez-Chantar , Gunnar Dittmar , and Ugo Mayor
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