Advanced Glycation of Cellular Proteins as a Possible Component of "Master Biological Clock"
During the last decade, evidence has accumulated supporting a hypothesis that aging is genetically programmed and, therefore, precisely timed. This hypothesis poses a question: what is the mechanism of the biological clock that controls aging? Detection of advanced glycation end-products (AGE) is one of the possible principles underlying the functioning of the biological clock. Protein glycation is an irreversible, non-enzymatic and relatively slow process. Moreover, many types of cells have receptors that can detect AGE level. We propose the existence of a protein that has a lifespan comparable to that of the whole organism. The interaction of the advanced glycation end-product generated from this protein with a specific AGE-receptor might initiate apoptosis in a vitally important non-regenerating tissue that produces a primary juvenile hormone. This results in an age-dependent decrease in the level of this hormone, leading to senescence of the organism.