Oxidative damage to cellular lipids is a contributing factor to aging, as well as many peripheral and central nervous system diseases. Reactive oxygen species-induced modification of polyunsaturated fatty acids results in the production of electrophilic metabolites capable of irreversibly modifying proteins, carbohydrates, and DNA. Examples of lipid electrophiles that have been extensively studied are 4-hydroxynonenal (4-HNE), 4- oxononenal (4-ONE), acrolein, and malondialdehyde. Adduction by lipid electrophiles distorts protein tertiary structure and typically has adverse effects on protein function. Despite an undeniable connection to aging as well as a multitude of diseases where oxidative stress occurs, the susceptibility of peptidyl-prolyl cis/trans isomerase A1 (Pin1) to adduction by different electrophiles has not been thoroughly investigated. In human colorectal carcinoma cells (RKO), I will map the adduction sites of Pin1 in vitro using proteomics. I will examine the potential downstream effects of 4-HNE and 4-ONE adduction to Pin1 in terms of substrate binding and prolyl isomerization activity. Furthermore, I propose that Pin1 modification by electrophiles results in an inability to catalyze the proline-directed isomerization of several Raf1 moieties necessary for dephosphorylation by protein phosphatase 2A, resulting in prolonged hyperphosphorylation/inactivation. This investigation represents the first study to mechanistically examine electrophile adduction of Pin1 and the subsequent regulatory fate of its substrates. The proposed research allows for significant insight into the cellular response to Pin1 protein modification as a consequence of lipid peroxidation.

Public Health Relevance

Oxidation of cellular lipids results in the release of reactive electrophiles that are capable of irreversibly damaging proteins, a process that has been suggested to underlie many human diseases. Pin1 is a protein that is overexpressed in cancer and suppressed in central nervous system disorders, suggesting an inherent relationship between Pin1 deregulation and disease. The union of these two subjects, oxidative damage to Pin1 and the ensuing cellular response, will expand our understanding of the consequences of Pin1 alterations as it relates to conditions associated with oxidative stress.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Postdoctoral Individual National Research Service Award (F32)
Project #
1F32GM100726-01A1
Application #
8315613
Study Section
Special Emphasis Panel (ZRG1-F04-A (20))
Program Officer
Fabian, Miles
Project Start
2012-05-01
Project End
2014-04-30
Budget Start
2012-05-01
Budget End
2013-04-30
Support Year
1
Fiscal Year
2012
Total Cost
$49,214
Indirect Cost
Name
Vanderbilt University Medical Center
Department
Biochemistry
Type
Schools of Medicine
DUNS #
004413456
City
Nashville
State
TN
Country
United States
Zip Code
37212
Aluise, Christopher D; Rose, Kristie; Boiani, Mariana et al. (2013) Peptidyl-prolyl cis/trans-isomerase A1 (Pin1) is a target for modification by lipid electrophiles. Chem Res Toxicol 26:270-9