title: ATP-driven processes of peroxisomal matrix protein import.
abstract: In peroxisomal matrix protein import two processes directly depend on the binding and hydrolysis of ATP, both taking place at the late steps of the peroxisomal import cycle. First, ATP hydrolysis is required to initiate a ubiquitin-transfer cascade to modify the import (co-)receptors. These receptors display a dual localization in the cytosol and at the peroxisomal membrane, whereas only the membrane bound fraction receives the ubiquitin modification. The second ATP-dependent process of the import cycle is carried out by the two AAA+-proteins Pex1p and Pex6p. These ATPases form a heterohexameric complex, which is recruited to the peroxisomal import machinery by the membrane anchor protein Pex15p. The Pex1p/Pex6p complex recognizes the ubiquitinated import receptors, pulls them out of the membrane and releases them into the cytosol. There the deubiquitinated receptors are provided for further rounds of import. ATP binding and hydrolysis are required for Pex1p/Pex6p complex formation and receptor export. In this review, we summarize the current knowledge on the peroxisomal import cascade. In particular, we will focus on the ATP-dependent processes, which are so far best understood in the model organism Saccharomyces cerevisiae.
authors.affiliation: Abteilung für Systembiochemie, Institut für Biochemie und Pathobiochemie, Medizinische Fakultät der Ruhr-Universität Bochum, Universitätsstr. 150, D-44780 Bochum.
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Schwerter
authors.affiliation: Abteilung für Systembiochemie, Institut für Biochemie und Pathobiochemie, Medizinische Fakultät der Ruhr-Universität Bochum, Universitätsstr. 150, D-44780 Bochum.
authors.forename: Immanuel
authors.initials: I
authors.lastname: Grimm
authors.affiliation: Biochemie Intrazellulärer Transportprozesse, Medizinische Fakultät der Ruhr-Universität Bochum, D-44780 Bochum.
authors.forename: Harald W
authors.initials: HW
authors.lastname: Platta
authors.affiliation: Abteilung für Systembiochemie, Institut für Biochemie und Pathobiochemie, Medizinische Fakultät der Ruhr-Universität Bochum, Universitätsstr. 150, D-44780 Bochum.
authors.forename: Ralf
authors.initials: R
authors.lastname: Erdmann
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D006801:Humans; D020675:Peroxisomes / Q000378:metabolism*; D021381:Protein Transport; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D054875:Ubiquitination
chemical_list: D029701:Saccharomyces cerevisiae Proteins; D000255:Adenosine Triphosphate
keywords: AAA+-ATPase; Pex; peroxin; peroxisome biogenesis; peroxisomes; protein translocation