SpeakerProf. Kimberly Beatty, Dept of Biomedical Engineering and Physiology & Pharmacology, OHSU, Host: Norbert Reich
Date and LocationWednesday January 31, 2018 11:00am to 12:00pm
Recent developments in fluorescence microscopy (FM), electron microscopy (EM), and correlative light and EM (CLEM) offer unprecedented opportunities for illuminating cellular structures at the nanoscale. It is now feasible to visualize and quantify the spatial organization of proteins and other macromolecules that enable cells to sense and respond to their environment. However, these efforts are restricted by the shortage of methods for attaching bright fluorescent or electron-dense reporters to target proteins. To overcome this barrier, we created a new protein labeling technology using Versatile Interacting Peptide (VIP) tags. These genetically-encoded tags are mediated by a heterodimeric coiled-coil interaction. Tags are small (5-7 kDa) and compatible with a variety of chemical reporters (e.g., gold, Qdots, organic dyes). The reporter can be selected to match a particular imaging application, which enhances the versatility of our approach. We used our first coiled-coil tag, heterodimeric CoilY/CoilZ, to detect fluorophore-labeled proteins in cell lysates and in cells. Labeling was rapid and highly specific. The CoilY/Z pair was bidirectional and either CoilY or CoilZ could be used as the probe peptide for labeling a target protein. This feature enabled us to obtain four-color images of ZipY-mCherry and ZipZ-GFP in transfected cells. We are currently developing new VIP tags and using this technology to investigate receptor trafficking and signaling networks. Our long-term goal for this project is to empower researchers across the biological sciences to simultaneously localize and track multiple distinct proteins with nanoscale precision.