Projects per year
BACKGROUND: The ubiquitin-proteasome system (UPS) controls the stability, localization and/or activity of the proteome. However, the identification and characterization of complex individual ubiquitination cascades and their modulators remains a challenge. Here, we report a broadly applicable, multiplexed, miniaturized on-bead technique for real-time monitoring of various ubiquitination-related enzymatic activities. The assay, termed UPS-confocal fluorescence nanoscanning (UPS-CONA), employs a substrate of interest immobilized on a micro-bead and a fluorescently labeled ubiquitin which, upon enzymatic conjugation to the substrate, is quantitatively detected on the bead periphery by confocal imaging.
RESULTS: UPS-CONA is suitable for studying individual enzymatic activities, including various E1, E2, and HECT-type E3 enzymes, and for monitoring multi-step reactions within ubiquitination cascades in a single experimental compartment. We demonstrate the power of the UPS-CONA technique by simultaneously following ubiquitin transfer from Ube1 through Ube2L3 to E6AP. We applied this multi-step setup to investigate the selectivity of five ubiquitination inhibitors reportedly targeting different classes of ubiquitination enzymes. Using UPS-CONA, we have identified a new activity of a small molecule E2 inhibitor, BAY 11-7082, and of a HECT E3 inhibitor, heclin, towards the Ube1 enzyme.
CONCLUSIONS: As a sensitive, quantitative, flexible, and reagent-efficient method with a straightforward protocol, UPS-CONA constitutes a powerful tool for interrogation of ubiquitination-related enzymatic pathways and their chemical modulators, and is readily scalable for large experiments.
- Bead-based assay
- Confocal fluorescence
- Ubiquitination assay
FingerprintDive into the research topics of 'Real-time tracking of complex ubiquitination cascades using a fluorescent confocal on-bead assay'. Together they form a unique fingerprint.
1/12/11 → 30/11/16
1/12/11 → 30/11/16
Koszela, J. (Creator), Pham, N. T. (Creator), Evans, D. (Creator), Mann, S. (Creator), Perez Pi, I. (Creator), Shave, S. (Creator), Ceccarelli, D. F. (Creator), Sicheri, F. (Creator), Tyers, M. D. (Creator) & Auer, M. (Creator), Edinburgh DataShare, 18 Jul 2018