MITOCHONDRIAL FISSION,FUSION AND APOPTOSIS

Mitochondria are highly dynamic organelles in a living cell,and display continuous movement,fusion and fission to form mitochondrial reticulum.Mitochondrial fission and fusion are highly regulated by a number of proteins.Mitochondrial fission is regulated by several proteins called Dnm1p,Fis1p,Mdv1p and Caf4p in yeast and Drp1,Fis1 in mammalian.On the other hand,mitochondrial fusion is mediated by an out-membrane protein,fuzzy onions(Fzo1p)in yeast,or its homologues mitofusion 1(Mfn1)and Mfn2 in mammalian.An intermembrane protein,Mgm1p in yeast and OPA1 in mammalian,involved in inner membrane fusion.Upon apoptotic stimulation,mitochondrial reticulum become fragmented.Inhibition of this process could partially prevents the release of cytochrome c and consequently cell apoptosis.Maintaining normal mitochondrial morphology is important for mitochondrial function and mitochondrial physiology,and defects in mitochondrial fission and fusion may cause severe diseases.