We have cloned PEX15 which is required for peroxisome biogenesis in Saccharomyces cerevisiae. pex15Delta cells are characterized by the cytosolic accumulation of peroxisomal matrix proteins containing a PTS1 or PTS2 import signal, whereas peroxisomal membrane proteins are present in peroxisomal remnants. PEX15 encodes a phosphorylated, integral peroxisomal membrane protein (Pex15p). Using multi...

Peroxisomal oxidation yields metabolites that are more efficiently utilized by mitochondria. This is of potential clinical importance because reduced fatty acid oxidation is suspected to promote excess lipid accumulation in obesity-associated insulin resistance. Our purpose was to assess peroxisomal contributions to mitochondrial oxidation in mixed gastrocnemius (MG), liver, and left ventricle ...

Zellweger syndrome and related disorders represent a group of lethal, genetically heterogeneous diseases. These peroxisome biogenesis disorders (PBDs) are characterized by defective peroxisomal matrix protein import and comprise at least 10 complementation groups. The genes defective in seven of these groups and more than 90% of PBD patients are now known. Here we examine the distribution of pe...

Zellweger syndrome (ZS) is a peroxisomal disorder with a multiple congenital anomalies, characterized by stereotypical facies, profound hypotonia, organ involvement including cerebral, retinal, hepatic, and renal. Herein, a 3-month-old female with ZS is presented who was referred because of increased liver enzymes (subclinical hepatitis), which was detected in work-up of her neck cyst, severe h...

Peroxisomes are subcellular organelles and are present in virtually all eukaryotic cells. Characteristic features of these organelles are their inducibility and their functional versatility. Their importance in the intermediary metabolism of cells is exemplified by the discovery of several inborn, fatal peroxisomal errors in man, the so-called peroxisomal disorders. Recent findings in research ...

A specific function for peroxisomal β-oxidation in inflorescence development in Arabidopsis thaliana is suggested by the mutation of the abnormal inflorescence meristem 1 gene, which encodes one of two peroxisomal multifunctional proteins. Therefore, it should be possible to identify other β-oxidation mutants that recapitulate the aim1 phenotype. Three genes encode peroxisomal 3-ketoacyl-CoA th...

We have identified and purified six subforms of peroxisomes, designated P1 to P6, from the yeast, Yarrowia lipolytica. An analysis of trafficking of peroxisomal proteins in vivo suggests the existence of a multistep peroxisome assembly pathway in Y. lipolytica. This pathway operates by conversion of peroxisomal subforms in the direction P1, P2-->P3-->P4-->P5-->P6 and involves the import of vari...

1. The induction of peroxisomal beta-oxidation activities by bezafibrate in cultured rat hepatocytes and in the rat in vivo was prevented by inhibitors of carnitine acyltransferase, e.g. 2-bromopalmitate, 2-[5-(4-chlorophenyl)pentyl]oxirane-2-carboxylate or 2-tetradecylglycidic acid. 2. The prevention of peroxisomal proliferation by carnitine palmitoyltransferase inhibitors could not be account...

Most proteins destined for the peroxisomal matrix depend on the peroxisomal targeting signals (PTSs), which require the PTS receptor PEX5, whose deficiency causes fatal human peroxisomal biogenesis disorders (PBDs). TRIM37 gene mutations cause muscle-liver-brain-eye (mulibrey) nanism. We found that TRIM37 localizes in peroxisomal membranes and ubiquitylates PEX5 at K464 by interacting with its ...