MITOCHONDRIAL BIOGENESIS IN STRIATED-MUSCLE

Mitochondrial biogenesis (synthesis) has been observed to occur in ske letal muscle in response to chronic use. It also occurs in cardiac mus cle during growth and hypertrophy, and it may be impaired during the a ging process. This review summarizes the literature on the processes o f mitochondrial biogenesis at the biochemical and molecular levels, wi th particular reference to striated muscles. Mitochondrial biogenesis involves the expression of nuclear and mitochondrial genes and the coo rdination of these two genomes, the synthesis of proteins and phosphol ipids and their import into the organelle, and the incorporation of th ese lipids and proteins into their appropriate locations within the ma trix, inner or outer membranes. The emphasis is on the regulation of t hese events, with information derived in part from other cellular syst ems. Although descriptions of mitochondrial content changes in heart a nd skeletal muscle during altered physiological states are plentiful, much work is needed at the molecular level to investigate the regulato ry processes involved. A knowledge of biochemical and molecular biolog y techniques is essential for continued progress in the field. This is a promising area, and potential new avenues for future research are s uggested.