Peroxisomal Membrane and Matrix Protein Import Using a Semi-Intact Mammalian Cell System
Peroxisomes are essential intracellular organelles that catalyze a number of essential metabolic pathways including β-oxidation of very long chain fatty acids, synthesis of plasmalogen, bile acids, and generation and degradation of hydrogen peroxide. These peroxisomal functions are accomplished by strictly and spatiotemporally regulated compartmentalization of the enzymes catalyzing these reactions. Defects in peroxisomal protein import result in inherited peroxisome biogenesis disorders in humans. Peroxisomal matrix and membrane proteins are synthesized on free ribosomes and transported to peroxisomes in a manner dependent on their specific targeting signals and their receptors. Peroxisomal protein import can be analyzed using a semi-intact assay system, in which targeting efficiency is readily monitored by immunofluorescence microscopy. Furthermore, cytosolic factors required for peroxisomal protein import can be manipulated, suggesting that the semi-intact system is a useful and convenient system to uncover the molecular mechanisms of peroxisomal protein import.
Key wordsImport receptors Peroxisome Peroxisome targeting signals Protein import Semi-intact cells
This work was supported in part by Grants-in-Aid for Scientific Research (24247038, 25112518, 25116717, 26116007, and 15K14511 to Y.F.; 26440032 to K.O.) from the Ministry of Education, Culture, Sports, Science and Technology of Japan, and grants from the Takeda Science Foundation, the Naito Foundation, and the Japan Foundation for Applied Enzymology.
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