Abstract
The ebb and flow of cellular life depends largely on signaling pathways and networks, which are regulated by specific protein-protein interactions. These interactions often involve assembly of large signaling complexes containing many different protein kinases, protein phosphatases, their substrates, and scaffold proteins. Identification of protein complexes is the key to understanding cellular functions. One of the techniques used for the isolation of protein complexes is the affinity purification system. Inhibitors of 3-hydroxyl-3-methyglutaryl coenzyme A (HMG-CoA) reductase (i.e., statins) exert cholesterol-independent vasoprotective effects that are mediated, in part, through the activation of Akt. However, the molecular mechanism remains unknown. To elucidate the molecular mechanisms of the pleioptropic effects of statins, we searched for the binding molecule of Akt1 by using a combined mass spectrometry and affinity purification strategy. By this technique, we identified the protein-protein interactions of 23 proteins from statin-treated rat aortic endothelial cells (rAECs). Our results suggest that this approach is very effective and statin activates many Akt down-stream targets, not only endothelial nitric oxide synthase (eNOS). The methodology presented here would provide a new tool for chemical proteomics in medicinal science.
