The long-standing paradigm that all peroxisomal proteins are imported post-translationally into pre-existing peroxisomes has been challenged by the detection of peroxisomal membrane proteins (PMPs) inside the endoplasmic reticulum (ER). In mammals, the mechanisms of ER entry and exit of PMPs are completely unknown. We show that the human PMP PEX3 inserts co-translationally into the mammalian ER...

The peroxisome is an organelle with essential roles in lipid metabolism, maintenance of reactive oxygen species homeostasis, and anaplerotic replenishment of tricarboxylic acid cycle intermediates destined for mitochondria (Islinger et al., 2012; Beach and Titorenko, 2013; Wanders, 2014). Peroxisomes constitute a dynamic endomembrane system. The homeostatic state of this system is upheld via tw...

Previously it has been shown that the endogenous Arabidopsis peroxin, AtPEX16, coexisted at steady state in membranes of the endoplasmic reticulum (ER) and peroxisomes. Herein, an ER-to-peroxisome trafficking pathway and the requisite molecular targeting signals for mycAtPEX16 transiently expressed in Arabidopsis and tobacco BY-2 suspension cells are described. Immunofluorescent mycAtPEX16 was ...

In the filamentous fungus Neurospora crassa, glyoxysomes and Woronin bodies coexist in the same cell. Because several glyoxysomal matrix proteins and also HEX1, the dominant protein of Woronin bodies, possess typical peroxisomal targeting signals, the question arises as to how protein targeting to these distinct yet related types of microbodies is achieved. Here we analyzed the function of the ...

SI-1 The PEX11 family: Deciphering a key player of peroxisomal proliferation Kornelija Pranjić, Johannes Koch, Anja Huber, Andreas Hartig, Cécile Brocard and Friedrich Kragler* # University of Vienna, Department of Biochemistry, Center of Molecular Biology, MFPL, Austria; * Max Planck Institute of Molecular Plant Physiology, Golm, Germany In plants, peroxisomes are involved in a variety of esse...

To investigate peroxisome assembly and human peroxisome biogenesis disorders (PBDs) such as Zellweger syndrome, thirteen different complementation groups (CGs) of Chinese hamster ovary (CHO) cell mutants defective in peroxisome biogenesis have been isolated and established as a model research system. Successful gene-cloning studies by a forward genetic approach utilized a rapid functional compl...

Peroxisomal matrix proteins carry peroxisomal targeting signals (PTSs), PTS1 or PTS2, and are imported into the organelle with the assistance of peroxin (PEX) proteins. From a microscopy-based screen to identify Arabidopsis (Arabidopsis thaliana) mutants defective in matrix protein degradation, we isolated unique mutations in PEX2 and PEX10, which encode ubiquitin-protein ligases anchored in th...