How the proteasome recognizes its ubiquitinated substrates

Authors

• X Chen
• Y Shi
• S Elsasser
• BB Stocks
• SG Tarasov
• JR Engen
• D Finley
• KJ Walters

Abstract

Proteolysis by the proteasome is essential for diverse cellular events including orderly cell cycle progression, activation of transcription factors, and protein quality control. Most substrates of the proteasome are first ubiquitinated by an enzymatic cascade, allowing for their recognition by ubiquitin receptors that are intrinsic to the proteasome or that shuttle them there. We have used NMR spectroscopy in conjunction with yeast genetics experiments to identify the key receptors for ubiquitinated substrates in the proteasome. Ubiquitin chains of diverse linkage type can be used to signal for protein degradation by the proteasome and we have dissected the ubiquitin chain preferences of these ubiquitin receptors. Moreover, we have solved the structure of each of these ubiquitin receptors in complex with various ubiquitin species. Altogether this work provides fundamental information on how cells target proteins for proteolysis by the proteasome.

Scientific Focus Area: Structural Biology

This page was last updated on Friday, March 26, 2021