Protein translocation machineries of peroxisomes

Targeting of peroxisomal matrix and membrane proteins is performed by disti nct transport machineries and requires the concerted action of at least 23 peroxins, Cargo recognition takes place in the cytosol and the multiple bin ding sites for peroxisomal signal sequence receptors at the peroxisomal mem brane reflect the existence of an import cascade where the cargo-loaded rec eptors successively interact with different components of the import machin ery. These interactions are likely to trigger conformational changes of the proteins within the import cascade which are required for the consecutive steps of peroxisomal protein import: docking, translocation, cargo release and receptor recycling. (C) 2001 Federation of European Biochemical Societi es. Published by Elsevier Science B.V. All rights reserved.