Biogenesis of Peroxisomes

Abstract

Peroxisomes are ubiquitous subcellular organelles found in all eukaryotic cells. This paper summarizes the current status of research in the areas of peroxisomal protein import and biogenesis. Much is known about the peroxisomal targeting signals (PTSs) that transport proteins to the peroxisomal matrix and membrane. The use of multiple strategies has led to the isolation and characterization of yeast and mammalian pex mutants deficient in peroxisomal protein import, biogenesis or segregation of the organelle to daughter cells. Biochemical and genetic analyses of wild-type and pex mutant cells has led to the characterization of several PTS receptors, and the peroxisomal docking proteins for these receptors. Details of the translocation of proteins across the peroxisomal membrane remain to be elucidated. An investigation of the early stages of peroxisome biogenesis has revealed some unusual features such as the involvement of vesicles, and perhaps the endoplasmic reticulum, in peroxisome biogenesis. The conservation of many PEX genes between yeasts and mammals is leading to insights about the molecular basis of a number of human peroxisomal disorders.