Age-Dependent Changes in Protein Phosphorylation: Differential Studies in Rat Tissue

Abstract

Protein phosphorylation is a reversible process that is involved in cellular growth, division and signaling. The mechanisms for protein phosphorylation can be significantly altered during the aging process. These alterations are responsible for various deleterious effects and have been associated with several age-related disease states. In an effort to elucidate which mechanisms are altered during the aging process we have developed a series of proteomic methods to characterize phosphorylation differences between five month and thirty-four month old rats. Utilizing skeletal muscle and cerebellum tissue extracts from these animals we have performed two-dimensional polyacrylamide gel electrophoresis followed by image analysis of the patterns resulting from staining with both a phosphoprotein stain and a total protein stain and subsequent identification by nanoelectrospray MS/MS. We have also made an effort to understand these phosphorylation differences by exploring the impact of reactive oxygen species on protein phosphorylation in C2C12 myoblast cells.