The proteasome and its function in the aging process

The aging process is characterized by a progresswe loss of function and a decline in the functional capacities of the organism, leading to death. The nature of the processes leading to the losses of functions are not well understood until today. A number of theories have been postulated, including a hypothesis emphasizing the role of reactive oxygen species (ROS) as a fundamental causal factor for the aging process. Among others oxidative damage to proteins ROS plays a key role in the aging process. Oxidative modification of proteins is generally leading to dysfunctional proteins. These non-functional proteins normally undergo preferential degradation. Within the cell the mare proteolytic machinery involved in the degradation of oxidized proteins is the proteasomal system, consisting of a multicatalytic protease complex - the proteasome and numerous regulatory factors. The proteasome is a highly conserved structure distributed in the cytosol, nucleus and endoplasmatic reticulum of mammalian cells. Since the p roteasome itself is also exposed to oxidative stress during the aging process, several studies were done investigating the role and the activity of the proteasomal system during aging. This review will emphasize the current knowledge about the activity of the protesomal system and its possible involvement in the aging process.