Split-TurboID enables contact-dependent proximity labeling in cells

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 117; no. 22; pp. 12143 - 12154
• Main Authors: Cho, Kelvin F., Branon, Tess C., Rajeev, Sanjana, Svinkina, Tanya, Udeshi, Namrata D., Thoudam, Themis, Kwak, Chulhwan, Rhee, Hyun-Woo, Lee, In-Kyu, Carr, Steven A., Ting, Alice Y.
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 02.06.2020
• Subjects: Apposition; Biological Sciences; Biotinylation; Endoplasmic reticulum; Endoplasmic Reticulum - metabolism; Fractionation; HEK293 Cells; Humans; Labeling; Membrane proteins; Membrane Proteins - metabolism; Membranes; Mitochondria; Mitochondria - metabolism; Mitochondrial Membranes - metabolism; Proteins; Proteome - analysis; Proteome - metabolism; Proximity; Staining and Labeling; ER–mitochondria contacts; proximity labeling; split-TurboID
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.1919528117

Proximity labeling catalyzed by promiscuous enzymes, such as TurboID, have enabled the proteomic analysis of subcellular regions difficult or impossible to access by conventional fractionation-based approaches. Yet some cellular regions, such as organelle contact sites, remain out of reach for current PL methods. To address this limitation, we split the enzyme TurboID into two inactive fragments that recombine when driven together by a protein–protein interaction or membrane–membrane apposition. At endoplasmic reticulum–mitochondria contact sites, reconstituted TurboID catalyzed spatially restricted biotinylation, enabling the enrichment and identification of >100 endogenous proteins, including many not previously linked to endoplasmic reticulum–mitochondria contacts. We validated eight candidates by biochemical fractionation and overexpression imaging. Overall, split-TurboID is a versatile tool for conditional and spatially specific proximity labeling in cells.