Degradation of excess peroxisomes in mammalian liver cells by autophagy and other mechanisms.
Here we discuss the mechanisms for the degradation of excess peroxisomes in mammalian hepatocytes which include (a) autophagy, (b) the action of peroxisomal Lon protease and (c) the membrane disrupting effect of 15-lipoxygenase. A recent study using Atg7 conditional-knock-out mice revealed that 70-80% of excess peroxisomes are degraded by the autophagic process. The remaining 20-30% of excess peroxisomes is most probably degraded by the action of peroxisomal Lon protease. Finally, a selective disruption of the peroxisomal membrane has been shown to be mediated by 15-lipoxygenase activity which is followed by diffusion of matrix proteins into the cytoplasm and cytoplasmic proteolysis.
Yokota
Sadaki
S
Section of Functional Morphology, Faculty of Pharmaceutical Sciences, Nagasaki International University, Huis Ten Bosch 2825-7, Sasebo, Nagasaki 859-3298, Japan. syokota@niu.ac.jp
Dariush Fahimi
H
H
D000818:Animals; D001093:Arachidonate 15-Lipoxygenase / Q000378:metabolism; D001343:Autophagy / Q000502:physiology*; D003593:Cytoplasm / Q000378:metabolism / Q000648:ultrastructure; D022781:Hepatocytes / Q000502:physiology* / Q000648:ultrastructure; D007425:Intracellular Membranes / Q000502:physiology*; D051379:Mice; D020675:Peroxisomes / Q000502:physiology*; D049070:Protease La / Q000378:metabolism
D001093:Arachidonate 15-Lipoxygenase; D049070:Protease La