The screens, done independently by one Harvard-led and one MIT-led research team, both identified the protein Grb10 as an mTOR substrate and a likely tumor suppressor involved in regulating PI3K activity.
In particular, the study focused on signaling networks tied to CTL chromatin regulation with the aim of better understanding the systems of gene regulation characteristic of these cells, said one of the researchers.
The study showed that EGF signaling impacts ubiquitination across a wide range of protein networks and is one of the first to demonstrate cross-talk between ubiquitin-regulated and phospho-regulated signaling pathways, said one of the scientists.
Their study, Mann said, suggests that protein expression is more similar across cell types than previously thought — a finding with implications for drug development as well as basic cell biology research.
The collaboration, which aims to characterize the tryptic peptides of the 5,000 proteins in order to generate mass spectroscopy assays for them, brings together ISB's mass spectroscopy expertise and OriGene's extensive human protein collection.
In a study published in Nature Methods, Matthias Mann and his colleagues at the Max Planck Institute for Biochemistry describe a method they have developed to expand the use of SILAC for tissue samples and eventually to researchers who may not be specialists in mass spectrometry.