We measured total, mitochondrial and peroxisomal capacities for b-oxidation of [1-C]palmitate in homogenates of liver, kidney and heart from pigs within 0.5 h after birth (0 h, unfed) and at 24 h (suckled or unfed), 10 d (suckled or 24-h food-deprived), 21 d (suckled or 24-h food-deprived) and 5 mo (overnight food-deprived) of age. Assays were conducted in the absence (total b-oxidation) or pre...

Peroxisomes are organelles responsible for multiple metabolic pathways including, the biosynthesis of plasmalogens, a class of phospholipids, and the beta-oxidation of very-long-chain fatty acids (VLCFA). Lack of peroxisomes or dysfunction in any of their normal functions is the cellular basis for human peroxisomal disorders. Here we used mouse models to understand and define the biochemical an...

Pex11p family proteins are key players in peroxisomal fission, but their molecular mechanisms remains mostly unknown. In the present study, overexpression of Pex11pβ caused substantial vesiculation of peroxisomes in mammalian cells. This vesicle formation was dependent on dynamin-like protein 1 (DLP1) and mitochondrial fission factor (Mff), as knockdown of these proteins diminished peroxisomal ...

In plants and other eukaryotes, long-chain acyl-CoAs are assumed to be imported into peroxisomes for beta-oxidation by an ATP binding cassette (ABC) transporter. However, two genes in Arabidopsis thaliana, LACS6 and LACS7, encode peroxisomal long-chain acyl-CoA synthetase (LACS) isozymes. To investigate the biochemical and biological roles of peroxisomal LACS, we identified T-DNA knockout mutan...

BACKGROUND Peroxisomal metabolic machinery requires a continuous flow of organic and inorganic solutes across peroxisomal membrane. Concerning small solutes, the molecular nature of their traffic has remained an enigma. METHODS/PRINCIPAL FINDINGS In this study, we show that disruption in mice of the Pxmp2 gene encoding Pxmp2, which belongs to a family of integral membrane proteins with unknow...

We previously reported the cloning of the PAY5 gene of the yeast Yarrowia lipolytica by complementation of the peroxisome assembly mutant pay5-1 (Eitzen, G. A., Titorenko, V. I., Smith, J. J., Veenhuis, M., Szilard, R. K., and Rachubinski, R. A. (1996) J. Biol. Chem. 271, 20300-20306). The peroxisomal integral membrane protein Pay5p is a homologue of mammalian PAF-1 proteins, which are essentia...

Peroxisomes constitute a dynamic compartment in all nucleated cells. They fulfill diverse metabolic tasks in response to environmental changes and cellular demands. This adaptation is implemented by modulation of the enzyme content of the organelles, which is accomplished by dynamically operating peroxisomal protein transport machineries. Soluble import receptors recognize their newly synthesiz...

Epitope tagging is a method of expressing proteins whereby an epitope for a specific monoclonal antibody is fused to a target protein using recombinant DNA techniques. The aim of this study was to sub-clone the peroxisomal protein (PEP) cDNA into a mammalian expression vector leading to the formation of a  chimeric PEP-cDNA containing the FLAG epitope. The FLAG-PEP recombinant cDNA was construc...

Peroxisomes perform many essential functions in eukaryotic cells. The weight of evidence indicates that these organelles divide by budding from preexisting peroxisomes. This process is not understood at the molecular level. Peroxisomal proliferation can be induced in Saccharomyces cerevisiae by oleate. This growth substrate is metabolized by peroxisomal enzymes. We have identified a protein, Pm...

To elucidate unknown mammalian peroxisomal enzymes and functions, we subjected M13 phage expressing fusions between the gene encoding protein VI and a rat liver cDNA library to an immunoaffinity selection process in vitro (biopanning) with the use of antibodies raised against peroxisomal subfractions. In an initial series of biopanning experiments, four different cDNA clones were obtained. Thes...