Peroxisomes are ubiquitous organelles which participate in a variety of essential biochemical pathways. An intimate interrelationship between peroxisomes and mitochondria is emerging in mammals, where both organelles cooperate in fatty acid β-oxidation and cellular lipid homeostasis. As mitochondrial fatty acid β-oxidation is lacking in yeast and plants, suitable genetically accessible model sy...

Here we examine peroxisomes in living plant cells using transgenic Arabidopsis thaliana plants expressing the green fluorescent protein (GFP) fused to the peroxisome targeting signal 1 (PTS1). Using time-lapse laser scanning confocal microscopy we find that plant peroxisomes exhibit fast directional movement with peak velocities approaching 10 microm s(-1). Unlike mammalian peroxisomes which mo...

Very recently, autophagy has been recognized as an important degradation pathway for quality control of peroxisomes in Arabidopsis plants. To further characterize the role of autophagy in plant peroxisome degradation, we generated stable transgenic suspension-cultured cell lines of heterotrophic Nicotiana tabacum L. cv. Bright Yellow 2 expressing a peroxisome-targeted version of enhanced yellow...

Aspergillus nidulans is able to synthesize penicillin and serves as a model to study the regulation of its biosynthesis. Only three enzymes are required to form the beta lactam ring tripeptide, which is comprised of l-cysteine, l-valine and l-aminoadipic acid. Whereas two enzymes, AcvA and IpnA localize to the cytoplasm, AatA resides in peroxisomes. Here, we tested a novel strategy to improve p...

Pex11p (formerly Pmp27) has been implicated in peroxisomal proliferation (Erdmann, R., and G. Blobel. 1995. J. Cell Biol. 128; 509-523; Marshall, P.A., Y.I. Krimkevich, R.H. Lark, J.M. Dyer, M. Veenhuis, and J.M. Goodman, 1995. J. Cell Biol. 129; 345-355). In its absence, peroxisomes in Saccharomyces cerevisiae fail to proliferate in response to oleic acid; instead, one or two large peroxisomes...

The peroxin Pex19p functions in peroxisomal membrane assembly. Here we mapped functional domains of human Pex19p comprising 299 amino acids. Pex19p mutants deleted in the C-terminal CAAx farnesylation motif, the C-terminal 38 amino acid residues and the N-terminal 11 residues, maintained peroxisome-restoring activity in pex19 cells. The sequence 12-261 was essential for re-establishing peroxiso...

Tomato bushy stunt virus (TBSV), a positive-strand RNA virus, causes extensive inward vesiculations of the peroxisomal boundary membrane and formation of peroxisomal multivesicular bodies (pMVBs). Although pMVBs are known to contain protein components of the viral membrane-bound RNA replication complex, the mechanisms of protein targeting to peroxisomal membranes and participation in pMVB bioge...

Peroxisomes are arguably the most biochemically versatile of all eukaryotic organelles. Their metabolic functions vary between different organisms, between different tissue types of the same organism and even between different developmental stages or in response to changed environmental conditions. New functions for peroxisomes are still being discovered and their importance is underscored by t...

Sec16 plays a key role in the formation of coat protein II vesicles, which mediate protein transport from the endoplasmic reticulum (ER) to the Golgi apparatus. Mammals have two Sec16 isoforms: Sec16A, which is a longer primary ortholog of yeast Sec16, and Sec16B, which is a shorter distant ortholog. Previous studies have shown that Sec16B, as well as Sec16A, defines ER exit sites, where coat p...

Reduction-oxidation or "redox" reactions are an integral part of a broad range of cellular processes such as gene expression, energy metabolism, protein import and folding, and autophagy. As many of these processes are intimately linked with cell fate decisions, transient or chronic changes in cellular redox equilibrium are likely to contribute to the initiation and progression of a plethora of...