Return to search

Functional implications of electrophilic protein adducts

Oxidative stress is a contributing factor in a number of chronic diseases, including cancer, atherosclerosis, and neurodegenerative diseases. Lipid peroxidation that occurs during periods of oxidative stress and decomposition of these oxidized lipids results in the formation of lipid electrophiles. 4-Hydroxy-2-nonenal (HNE) and 4-oxo-2-nonenal (ONE) are two lipid aldehydes which are generated as a result of lipid peroxidation, and both can adduct nucleophilic side chains of amino acids in proteins. A large number of protein targets have been identified for HNE and ONE, consisting of an array of adduct structures Here, we show that these adducts have distinct functional implications on the activity and regulation of the target protein. CDK2, a key cell cycle kinase which regulates the G1/S-phase transition, is adducted by HNE for up to 16 h. The adduction of CDK2 inhibits kinase activity in vitro and in cells and delays cell cycle progression into S-phase following HNE treatment. PIN1 is a cis/trans isomerase, which plays a key role in regulating of a number of cell signaling pathways. PIN1 is modified by 4-oxo-2-nonenal ONE at the active-site Cys and forms a cross-link with a nearby Lys, thereby inactivating the protein. Using site-specific incorporation of deuterium in ONE, we were able to determine a mechanism of cross-link formation and definitively show that nucleophilic attack occurs at the third carbon of ONE. Histone proteins have also been shown to be preferential targets for ONE modification, and these proteins have a direct effect on the regulation of gene expression and chromatin structure. We have developed a method to selectively isolate regions of DNA associated with these adducted histones using click-chemistry. The method, coupled with next generation DNA sequencing, termed Click-Seq, shows few regions of enrichment, suggesting that ONE broadly adducts chromatin. Furthermore, the levels of these adducts are two orders of magnitude lower than the canonical histone modifications. Together, these data show that the lipid electrophile HNE and ONE can have a significant impact on enzyme activity, alterations in cell signaling pathway, and regulation of gene expression.

Identiferoai:union.ndltd.org:VANDERBILT/oai:VANDERBILTETD:etd-11172016-083939
Date17 November 2016
CreatorsCamarillo, Jeannie Marie
ContributorsJennifer A. Pietenpol, William P. Tansey, David Cortez, Daniel C. Liebler, Lawrence J. Marnett
PublisherVANDERBILT
Source SetsVanderbilt University Theses
LanguageEnglish
Detected LanguageEnglish
Typetext
Formatapplication/pdf
Sourcehttp://etd.library.vanderbilt.edu/available/etd-11172016-083939/
Rightsrestrictone, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Vanderbilt University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report.

Page generated in 0.0072 seconds