L. Van Dyck et T. Langer, ATP-dependent proteases controlling mitochondrial function in the yeast Saccharomyces cerevisiae, CELL MOL L, 56(9-10), 1999, pp. 825-842
Regulated protein degradation by ATP-dependent proteases plays a fundamenta
l role in the biogenesis of mitochondria. Membrane-bound and soluble ATP-de
pendent proteases have been identified in various subcompartments of this o
rganelle. Subunits composing these proteases are evolutionarily conserved f
rom yeast to humans and, in support of an endosymbiotic origin of mitochond
ria, evolved from prokaryotic ancestors: the PIM1/Lon protease is active in
the matrix of mitochondria, while the i-AAA protease and the m-AAA proteas
e mediate the turnover of inner membrane proteins. Most of the knowledge co
ncerning the biogenesis and the physiological role of ATP-dependent proteas
es comes from studies in the yeast Saccharomyces cerevisiae. Proteases were
found to be required for mitochondrial stasis, for the maintenance of the
morphology of the organelle and for mitochondrial genome integrity. ATP-dep
endent proteolysis is crucial for the expression of mitochondrially encoded
subunits of respiratory chain complexes and for the assembly of these comp
lexes. Hence, mitochondrial ATP-dependent proteases exert multiple roles wh
ich are essential for the maintenance of cellular respiratory competence.