Localization of Rab proteins to peroxisomes: A proteomics and immunofluorescence study

A proteomics screen was initiated to identify Rab proteins regulating transport to and away from peroxisomes. Mass spectrometry-based protein correlation profiling of rat liver organelles and immunofluorescence analysis of the peroxisome candidate Rab proteins revealed Rab6, Rab10, Rab14 and Rab18 to associate with the peroxisomal membrane. While Rab14 localized to peroxisomes predominantly in its dominant-active form, other Rab proteins associated with peroxisomes in both their GTP- and GDP-bound state. In summary, our data suggest that Rab6, Rab10, Rab14 and Rab18 associate with the peroxisomal compartment and similar as previously shown for Rab8, Rab18 in its GDP-bound state favors peroxisome proliferation. Structured summary of protein interactions: bifunctional enzyme, PEX11alpha, Rab-18, Rab-14, Rab-6A, Rab-10 and Rab-2A colocalize by cosedimentation through density gradient (View interaction) Catalase and Rab18 colocalize by fluorescence microscopy (View interaction) Rab14 and Catalase colocalize by fluorescence microscopy (View interaction) Rab6 and Catalase colocalize by fluorescence microscopy (View interaction) Rab10 and Catalase colocalize by fluorescence microscopy (View interaction) (C) 2013 Federation of European Biochemical Societies. Published by Elsevier B. V. All rights reserved.