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AJNR. American Journal of Neuroradiology 1992
Review
Topics: Child; Child, Preschool; Diffuse Cerebral Sclerosis of Schilder; Female; Humans; Infant; Infant, Newborn; Lysosomal Storage Diseases; Magnetic Resonance Imaging; Male; Microbodies; Mitochondria; Tomography, X-Ray Computed
PubMed: 1566722
DOI: No ID Found -
The Journal of Biological Chemistry Aug 1995
Review
Topics: Cytochrome P-450 Enzyme System; Enzyme Induction; Hydrocarbons; Microbodies; Phenobarbital; Steroids; Transcription, Genetic; Xenobiotics
PubMed: 7629130
DOI: 10.1074/jbc.270.31.18175 -
The EMBO Journal Dec 1985To determine how microbody enzymes enter microbodies, we are studying the genes for cytosolic and glycosomal (microbody) isoenzymes in Trypanosoma brucei. We have found... (Comparative Study)
Comparative Study
To determine how microbody enzymes enter microbodies, we are studying the genes for cytosolic and glycosomal (microbody) isoenzymes in Trypanosoma brucei. We have found three genes (A, B and C) coding for phosphoglycerate kinase (PGK) in a tandem array in T. brucei. Gene B codes for the cytosolic and gene C for the glycosomal isoenzyme. Genes B and C are 95% homologous, and the predicted protein sequences share approximately 45% amino acid homology with other eukaryote PGKs. The microbody isoenzyme differs from the cytosolic form and other PGKs in two respects: a high positive charge and a carboxy-terminal extension of 20 amino acids. Our results show that few alterations are required to redirect a protein from cytosol to microbody. From a comparison of our results with the unpublished data for three other glycosomal glycolytic enzymes we infer that the high positive charge represents the major topogenic signal for uptake of proteins into glycosomes.
Topics: Amino Acid Sequence; Animals; Base Sequence; Cytosol; DNA Restriction Enzymes; Genes; Humans; Isoenzymes; Microbodies; Phosphoglycerate Kinase; Sequence Homology, Nucleic Acid; Species Specificity; Trypanosoma brucei brucei
PubMed: 3004970
DOI: 10.1002/j.1460-2075.1985.tb04152.x -
Plant Molecular Biology Sep 1998Peroxisomes are small organelles with a single boundary membrane. All of their matrix proteins are nuclear-encoded, synthesized on free ribosomes in the cytosol, and... (Review)
Review
Peroxisomes are small organelles with a single boundary membrane. All of their matrix proteins are nuclear-encoded, synthesized on free ribosomes in the cytosol, and post-translationally transported into the organelle. This may sound familiar, but in fact, peroxisome biogenesis is proving to be surprisingly unique. First, there are several classes of plant peroxisomes, each specialized for a different metabolic function and sequestering specific matrix enzymes. Second, although the mechanisms of peroxisomal protein import are conserved between the classes, multiple pathways of protein targeting and translocation have been defined. At least two different types of targeting signals direct proteins to the peroxisome matrix. The most common peroxisomal targeting signal is a tripeptide limited to the carboxyl terminus of the protein. Some peroxisomal proteins possess an amino-terminal signal which may be cleaved after import. Each targeting signal interacts with a different cytosolic receptor; other cytosolic factors or chaperones may also form a complex with the peroxisomal protein before it docks on the membrane. Peroxisomes have the unusual capacity to import proteins that are fully folded or assembled into oligomers. Although at least 20 proteins (mostly peroxins) are required for peroxisome biogenesis, the role of only a few of these have been determined. Future efforts will be directed towards an understanding of how these proteins interact and contribute to the complex process of protein import into peroxisomes.
Topics: Membrane Proteins; Microbodies; Plant Cells; Plant Development; Plant Proteins; Plants
PubMed: 9738966
DOI: No ID Found -
Environmental Health Perspectives Nov 1982The phthalate ester di(2-ethylhexyl) phthalate is both a peroxisome proliferator and a hepatic carcinogen. Peroxisome proliferators as a class are hepatocarcinogenic in... (Review)
Review
The phthalate ester di(2-ethylhexyl) phthalate is both a peroxisome proliferator and a hepatic carcinogen. Peroxisome proliferators as a class are hepatocarcinogenic in rodent species. However, none of the peroxisome proliferators tested to date including the phthalate esters and related alcohol and acid analogs have demonstrated mutagenic or DNA-damaging activity in the in vitro Salmonella typhimurium/microsomal or the lymphocyte 3H-thymidine assays. A working hypothesis is proposed that peroxisome proliferation itself initiates neoplastic transformation of hepatic parenchymal cells by increasing intracellular rates of DNA-damaging reactive oxygen production. Evidence which supports such a hypothesis includes increased fatty acid beta-oxidation, elevated H2O2 levels, accumulation of peroxidized lipofuscin, disproportionately small increase in catalase, and elevated peroxisomal uricase activity which accompany peroxisome proliferation in hepatocytes. Direct testing of this hypothesis will provide insight into mechanisms of phthalate ester carcinogenicity and cytotoxicity.
Topics: Animals; Carcinogens; Liver; Liver Neoplasms; Microbodies; Neoplasms, Experimental; Organoids; Phthalic Acids; Salmonella typhimurium
PubMed: 6754363
DOI: 10.1289/ehp.824535 -
Die Naturwissenschaften Feb 1999Peroxisomes are organelles that perform a variety of functions, including the metabolism of hydrogen peroxide and the oxidation of fatty acids. Peroxisomes do not... (Review)
Review
Peroxisomes are organelles that perform a variety of functions, including the metabolism of hydrogen peroxide and the oxidation of fatty acids. Peroxisomes do not possess organellar DNA; all peroxisomal matrix proteins are post-translationally translocated into the organelle. The mechanism of peroxisomal protein translocation has been the subject of vigorous research in the past decade. Many of the proteins (peroxins, abbreviated Pex) that play critical roles in peroxisome biogenesis have been identified through functional complementation of yeast strains and of Chinese hamster ovary cell lines that are defective in peroxisome biogenesis. Researchers are now turning towards biochemical and genetic analyses of these peroxins to define their roles in peroxisome biogenesis and to discover interacting protein partners. Evidence suggests that some of the interacting partners include molecular chaperones. Several current models for peroxisomal protein import are presented.
Topics: Animals; CHO Cells; Cell Line; Cricetinae; Genetic Complementation Test; Humans; Membrane Proteins; Microbodies; Molecular Chaperones; Protein Folding; Protein Processing, Post-Translational; Proteins
PubMed: 10084148
DOI: 10.1007/s001140050572 -
Current Biology : CB Apr 1998Proteins are targeted to the membrane and matrix of peroxisomes by distinct pathways. Recent observations suggest a further route: a subset of peroxisomal membrane... (Review)
Review
Proteins are targeted to the membrane and matrix of peroxisomes by distinct pathways. Recent observations suggest a further route: a subset of peroxisomal membrane proteins might be targeted first to the endoplasmic reticulum, and from there to peroxisomes by vesicle-mediated transport.
Topics: Animals; Biological Transport, Active; Coatomer Protein; Endoplasmic Reticulum; Glycosylation; Humans; Liver; Membrane Proteins; Microbodies; Models, Biological; Phosphoproteins; Protein Binding; Saccharomyces cerevisiae Proteins
PubMed: 9560335
DOI: 10.1016/s0960-9822(98)70191-5 -
FEMS Microbiology Reviews Nov 2004In trypanosomatids (Trypanosoma and Leishmania), protozoa responsible for serious diseases of mankind in tropical and subtropical countries, core carbohydrate metabolism... (Review)
Review
In trypanosomatids (Trypanosoma and Leishmania), protozoa responsible for serious diseases of mankind in tropical and subtropical countries, core carbohydrate metabolism including glycolysis is compartmentalized in peculiar peroxisomes called glycosomes. Proper biogenesis of these organelles and the correct sequestering of glycolytic enzymes are essential to these parasites. Biogenesis of glycosomes in trypanosomatids and that of peroxisomes in other eukaryotes, including the human host, occur via homologous processes involving proteins called peroxins, which exert their function through multiple, transient interactions with each other. Decreased expression of peroxins leads to death of trypanosomes. Peroxins show only a low level of sequence conservation. Therefore, it seems feasible to design compounds that will prevent interactions of proteins involved in biogenesis of trypanosomatid glycosomes without interfering with peroxisome formation in the human host cells. Such compounds would be suitable as lead drugs against trypanosomatid-borne diseases.
Topics: Animals; Drug Design; Glycolysis; Humans; Leishmania; Microbodies; Models, Molecular; Peroxisomes; Protozoan Proteins; Trypanocidal Agents; Trypanosoma
PubMed: 15539076
DOI: 10.1016/j.femsre.2004.06.004 -
Biological Chemistry Feb 2023Oxalyl-CoA synthetase from is one of the most abundant peroxisomal proteins in yeast and hence has become a model to study peroxisomal translocation. It contains a...
Oxalyl-CoA synthetase from is one of the most abundant peroxisomal proteins in yeast and hence has become a model to study peroxisomal translocation. It contains a C-terminal Peroxisome Targeting Signal 1, which however is partly dispensable, suggesting additional receptor bindings sites. To unravel any additional features that may contribute to its capacity to be recognized as peroxisomal target, we determined its assembly and overall architecture by an integrated structural biology approach, including X-ray crystallography, single particle cryo-electron microscopy and small angle X-ray scattering. Surprisingly, it assembles into mixture of concentration-dependent dimers, tetramers and hexamers by dimer self-association. Hexameric particles form an unprecedented asymmetric horseshoe-like arrangement, which considerably differs from symmetric hexameric assembly found in many other protein structures. A single mutation within the self-association interface is sufficient to abolish any higher-level oligomerization, resulting in a homogenous dimeric assembly. The small C-terminal domain of yeast Oxalyl-CoA synthetase is connected by a partly flexible hinge with the large N-terminal domain, which provides the sole basis for oligomeric assembly. Our data provide a basis to mechanistically study peroxisomal translocation of this target.
Topics: Saccharomyces cerevisiae; Amino Acid Sequence; Cryoelectron Microscopy; Microbodies; Saccharomyces cerevisiae Proteins; Ligases
PubMed: 36694962
DOI: 10.1515/hsz-2022-0273 -
European Journal of Biochemistry Nov 1975Profuse appearance of microbodies was observed in the cells of methanol-utilizing yeasts in connection with the enhanced catalase activity. These microbodies were...
Profuse appearance of microbodies was observed in the cells of methanol-utilizing yeasts in connection with the enhanced catalase activity. These microbodies were isolated successfully by means of sucrose gradient centrifugation from the methanol-grown cells of Kloeckera sp. no. 2201. Localization of a flavin-dependent alcohol oxidase as well as characteristic microbody enzymes (catalase and D-amino acid oxidase) were ascertained in the isolated microbodies, whereas formaldehyde and formate dehydrogenases were detected in the cytoplasmic region. Localization of catalase in the isolated microbody was also demonstrated by the cytochemical technique with 3,3'-diaminobenzidine.
Topics: Alcohol Oxidoreductases; Catalase; Cytoplasm; Electron Transport Complex IV; Methanol; Microbodies; Microscopy, Electron; Mitosporic Fungi; Organoids
PubMed: 173538
DOI: 10.1111/j.1432-1033.1975.tb02482.x