Oxidative stress is a contributing factor to a number of diseases, including cancer, atherosclerosis, asthma, and neurodegenerative disease. 4-Hydroxy-2-nonenal (HNE), a lipid aldehyde generated from lipid peroxidation during periods of increased oxidative stress, has been shown to covalently modify cellular proteins, in many cases altering their activities. Previous proteomic studies have shown that CDK2, a cell cycle kinase responsible mainly for the G1/S transition, is modified by HNE. Here, we demonstrate CDK2 modification by HNE and show the functional alterations that occur as a result of modification. Tandem mass spectrometry revealed that HNE covalently adducts a number of residues on CDK2, most significantly His71 and His161, by Michael addition. Treatment of pure CDK2/cyclin E complexes with HNE led to a loss of kinase activity.  HNE treatment delayed cell cycle progression into S-phase in G1-arrested cells. The delay was not due to changes in the levels of CDK2 and PARP cleavage, an indicator of apoptosis, was not observed. Most importantly, the delay in S-phase entry was independent of p53 and p21. Click chemistry with alkynyl-HNE revealed that progression of electrophile-treated cells into S-phase corresponded to loss of CDK2 modification, possibly through protein turnover. These data suggest that modification of CDK2 inhibits its kinase activity and may alter its turnover, thereby inhibiting cell cycle progression.

CDK2 inhibition and cell cycle arrest through 4-hydroxy-2-nonenal modification

248th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.