Peroxisomal Membrane Proteins Contain Common Pex19p-binding Sites that Are an Integral Part of Their Targeting Signals
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- Hanspeter Rottensteiner
- Institut für Physiologische Chemie, Ruhr-Universität Bochum, 44780 Bochum, Germany
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- Achim Kramer
- Institut für Medizinische Immunologie, Universitätsklinikum Charité, 10115 Berlin, Germany
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- Stephan Lorenzen
- Institut für Biochemie, Universitätsklinikum Charité, 10115 Berlin, Germany
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- Katharina Stein
- Institut für Physiologische Chemie, Ruhr-Universität Bochum, 44780 Bochum, Germany
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- Christiane Landgraf
- Institut für Medizinische Immunologie, Universitätsklinikum Charité, 10115 Berlin, Germany
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- Rudolf Volkmer-Engert
- Institut für Medizinische Immunologie, Universitätsklinikum Charité, 10115 Berlin, Germany
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- Ralf Erdmann
- Institut für Physiologische Chemie, Ruhr-Universität Bochum, 44780 Bochum, Germany
説明
<jats:p> Targeting of peroxisomal membrane proteins (PMPs) is a multistep process that requires not only recognition of PMPs in the cytosol but also their insertion into the peroxisomal membrane. As a consequence, targeting signals of PMPs (mPTS) are rather complex. A candidate protein for the PMP recognition event is Pex19p, which interacts with most PMPs. However, the respective Pex19p-binding sites are ill-defined and it is currently disputed whether these sites are contained within mPTS. By using synthetic peptide scans and yeast two-hybrid analyses, we determined and characterized Pex19p-binding sites in Pex11p and Pex13p, two PMPs from Saccharomyces cerevisiae. The sites turned out to be composed of a short helical motif with a minimal length of 11 amino acids. With the acquired data, it proved possible to predict and experimentally verify Pex19p-binding sites in several other PMPs by applying a pattern search and a prediction matrix. A peroxisomally targeted Pex13p fragment became mislocalized to the endoplasmic reticulum in the absence of its Pex19p-binding site. By adding the heterologous binding site of Pex11p, peroxisomal targeting of the Pex13p fragment was restored. We conclude that Pex19p-binding sites are well-defined entities that represent an essential part of the mPTS. </jats:p>
収録刊行物
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- Molecular Biology of the Cell
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Molecular Biology of the Cell 15 (7), 3406-3417, 2004-07
American Society for Cell Biology (ASCB)