Mitochondrial events in the life and death of animals cell: A brief overview

Traditionally, mitochondria have been viewed as the "powerhouse" of the cel l, i.e., the site of the oxidative phosphorylation machinery involved in AT P production. Consequently, much of the research conducted on mitochondria over the past 4 decades has focused on elucidating both those molecular eve nts involved in ATP synthesis by oxidative phosphorylation and those involv ed in the biogenesis of the oxidative phosphorylation machinery. While monu mental achievements have been made, and continue to be made, in the study o f these remarkable but extremely complex processes essential for the life o f most animal cells, it has been only in recent years that a large body of biological and biomedical scientists have come to recognize that mitochondr ia participate in other important processes. Two of these are cell death an d aging which, not surprisingly, are related processes both involving, in p art, the oxidative phosphorylation machinery. This new awareness has sparke d a new and growing area of mitochondrial research, that has become of grea t interest to a wide variety of scientists ranging from those involved in e lucidating the role of mitochondria in cell death and aging to those intere sted in either suppressing or facilitating these processes as it relates to identifying new therapies or drugs for human disease. It is the purpose of this brief introductory review to provide an overview of those mitochondri al events involved in the life and death of animal cells and to indicate ho w these-events might relate to the human aging process. Much more is known, much remains controversial, and even more remains to be learned as indicat ed in the excellent set of minireviews that follow.