Mitochondria make a come back

This review attempts to summarize our present state of knowledge of mitocho ndria in relation to a number of areas of biology, and to indicate where fu ture research might be directed. In the evolution of eukaryotic cells mitoc hondria have for a long time played a prominent role. Nowadays their integr ation into many activities of a cell, and their dynamic behavior as subcell ular organelles within a cell and during cell division are a major focus of attention. The crystal structures of the major complexes of the electron t ransport chain (except complex I) have been established, permitting increas ingly detailed analyses of the important mechanism of proton pumping couple d to electron transport. The mitochondrial genome and its replication and e xpression are beginning to be understood in considerable detail, but more q uestions remain with regard to mutations and their repair, and the segregat ion of the mtDNA in oogenesis and development. Much emphasis and a large ef fort have recently been devoted to understand the role of mitochondria in p rogrammed cell death (apoptosis). The understanding of their central role i n mitochondrial diseases is a major achievement of the past decade. Finally , various drugs have traditionally played a part in understanding biochemic al mechanisms within mitochondria; the repertoire of drugs with novel and i nteresting targets is expanding. (C) 2001 Published by Elsevier Science B.V .