Chen, Chiao-LinHu, YanhuiUdeshi, NamrataLau, ThomasWirtz-Peitz, FrederikHe, LiTing, AliceCarr, StevenPerrimon, Norbert2019-09-212015Chen, Chiao-Lin, Yanhui Hu, Namrata D. Udeshi, Thomas Y. Lau, Frederik Wirtz-Peitz, Li He, Alice Y. Ting, Steven A. Carr, and Norbert Perrimon. 2015. “Proteomic Mapping in liveDrosophilatissues Using an Engineered Ascorbate Peroxidase.” Proceedings of the National Academy of Sciences 112 (39): 12093–98. https://doi.org/10.1073/pnas.1515623112.0027-84240744-28311091-6490http://nrs.harvard.edu/urn-3:HUL.InstRepos:41384508Characterization of the proteome of organelles and subcellular domains is essential for understanding cellular organization and identifying protein complexes as well as networks of protein interactions. We established a proteomic mapping platform in live Drosophila tissues using an engineered ascorbate peroxidase (APEX). Upon activation, the APEX enzyme catalyzes the biotinylation of neighboring endogenous proteins that can then be isolated and identified by mass spectrometry. We demonstrate that APEX labeling functions effectively in multiple fly tissues for different subcellular compartments and maps the mitochondrial matrix proteome of Drosophila muscle to demonstrate the power of APEX for characterizing subcellular proteomes in live cells. Further, we generate "MitoMax," a database that provides an inventory of Drosophila mitochondrial proteins with subcompartmental annotation. Altogether, APEX labeling in live Drosophila tissues provides an opportunity to characterize the organelle proteome of specific cell types in different physiological conditions.en-USJournal Article2019-09-2110.1073/pnas.1515623112