[Aging and Proteostasis]

It is no exaggeration to say that most biological processes are carried out by proteins. However, proteins in the cells of many animals, including humans, will be damaged by various non-physiological modifications with age. The accumulation of such damaged/abnormal proteins is thought to cause a decline in the physiological function of various tissues in aging individuals. To maintain normal physiological function, abnormal proteins must be restored to normal by repair enzymes or removed by protein degradation enzymes, and new molecules must be synthesized and replaced. However, the transcription factors responsible for inducing heat shock proteins involved in the repair of conformationally altered proteins and molecules in the proteasome involved in the degradation of damaged proteins, are altered with age as well. In other words, those proteins involved in maintaining the homeostasis of proteins are also altered themselves with age. This review summarizes the author's 44 years of research on "aging and proteostasis."