About the Seminar:

Understanding the cellular context of biomolecules at the atomic level is central for detailed chemical and mechanistic biological processes. Correlated light and cryo-electron microscopy (cryo-CLEM) is the state-of-the-art method for correlating atomic models within their cellular context. Cryo-electron tomography (cryo-ET) can produce 3D images of cell at 2-5 nm resolution. At this resolution, large biomolecules can be identified based on their shapes, whereas smaller biomolecules cannot be as reliably identified due to resolution limits. Cryo-ET practitioners have long sought out cloneable contrast agents, analogous to the fluorescent proteins used widely in optical microscopy. Fluorescent proteins like green fluorescent protein (GFP) are useful for localizing proteins in fluorescent light microscopy because the DNA encoding a fluorescent protein can be linked to the DNA of any protein. Expression of the DNA results in the GFP protein covalently attached to the protein of interest, where GFP fluorescence reveals the location of the protein of interest within the cell. There is currently no widely applied cloneable contrast agent in cryo-ET. As a result, there is no robust cloneable contrast agent in cryo-CLEM due to the shortcomings of cryo-ET labels. This talk reviews three recent and emergent strategies for localizing proteins in cryo-ET, highlighting the advances over prior state of the art and remaining limitations. This talk will also discuss ongoing research in the Ackerson lab developing cloneable contrast agents for both cryo-CLEM and cryo-ET.