Alice Ting (MIT)
MolBio Seminar Series
Alice Ting has been a faculty member in the MIT Chemistry Department since 2002. Her work has been on the development of probes and reporters for live cell imaging. To simultaneously harness the power of genetics and the power of chemistry, Alice’s lab has exploited enzymes that act on both protein and small-molecule substrates. Her lab has developed new technologies for imaging protein trafficking, protein-protein interactions, and enzymatic activity. Current research interests include imaging studies of synapse formation/development, and in vitro evolution of novel enzyme function.
Spatially-resolved proteomic mapping in living cells via peroxidase-mediated promiscuous biotinylation.
Microscopy and mass spectrometry (MS)-based proteomics are complementary techniques: the former provides spatiotemporal information in living cells, but only for a handful of recombinant proteins at a time, while the latter can detect thousands of endogenous proteins simultaneously, but only in lysed samples. In this talk, I will describe a new technology that combines the strengths of microscopy and MS by generating spatially and temporally-resolved proteomic maps of endogenous proteins within living cells. The method relies on a genetically targetable peroxidase enzyme that biotinylates nearby proteins, which are subsequently identified by MS. We used this approach to identify 495 proteins within the human mitochondrial matrix and 145 proteins within the mitochondrial intermembrane space (IMS), including 50 proteins that have never before been assigned to mitochondria. The labeling was exceptionally specific, able to distinguish between inner membrane proteins facing the matrix versus the IMS. Our catalog also revised the sub-mitochondrial localizations for several well-studied proteins, with the new assignments confirmed by electron microscopy.
Free and open to the university community and the public