Utilizing Quantitative Mass Spectrometry Methods to Identify Cell Cycle Specific Changes in Yeast 26S Proteasome Posttranslational Modifications and Interacting Network

摘要

The Ub-proteasome system (UPS) mediates cell cycle progression by targeting and degrading cyclins and inhibitory proteins, and functions integrally at several cell cycle checkpoints. Quantitative analysis of tandem-affinity purified cross-linked proteins (QTAX) is a powerful approach to identifying both strong and transient/weak interactions between large protein complexes. Past studies have utilized this strategy to map the 26S proteasome interaction network in asynchronous cells, however comprehensive analysis has yet to be applied to identify interaction network changes in response to cell cycle arrest. Using dual QTAX approaches in yeast, we have been able to characterize clusters of proteasome interacting proteins (PIPs) which interact with the proteasome in a comparable manner. It has been shown that function of the 26S proteasome can be modulated by its interacting partners. By mapping PIPs which display cyclical interaction with the 26S proteasome, we can begin to understand how the proteasome is regulated throughout the cell cycle.