Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P04040 (Catalase)
 3,577 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In rat liver, peroxisome proliferators induce profound changes in the number and protein composition of peroxisomes, which upon subcellular fractionation is reflected in heterogeneity in sedimentation properties of peroxisome populations. In this study we have investigated the time course of induction of the peroxisomal proteins catalase, acyl-CoA oxidase (ACO) and the 70 kDa peroxisomal membrane protein (PMP70) in different subcellular fractions. Rats were fed a di(2-ethylhexyl)phthalate (DEHP) containing diet for 8 days and livers were removed at different time-points, fractionated by differential centrifugation into nuclear, heavy and light mitochondrial, microsomal and soluble fractions, and organelle marker enzymes were measured. Catalase was enriched mainly in the light mitochondrial and soluble fractions, while ACO was enriched in the nuclear fraction (about 30%) and in the soluble fraction. PMP70 was found in all fractions except the soluble fraction. DEHP treatment induced ACO, catalase and PMP70 activity and immunoreactive protein, but the time course and extent of induction was markedly different in the various subcellular fractions. All three proteins were induced more rapidly in the nuclear fraction than in the light mitochondrial or microsomal fractions, with catalase and PMP70 being maximally induced in the nuclear fraction already at 2 days of treatment. Refeeding a normal diet quickly normalized most parameters. These results suggest that induction of a heavy peroxisomal compartment is an early event and that induction of 'small peroxisomes', containing PMP70 and ACO, is a late event. These data are compatible with a model where peroxisomes initially proliferate by growth of a heavy, possibly reticular-like, structure rather than formation of peroxisomes by division of pre-existing organelles into small peroxisomes that subsequently grow. The various peroxisome populations that can be separated by subcellular fractionation may represent peroxisomes at different stages of biogenesis.
 ...
PMID:Differential induction of peroxisomal populations in subcellular fractions of rat liver. 1134 45

Peroxisomes are ubiquitous organelles required for several metabolic functions. Their dysfunction is responsible for a group of human inherited disorders. In the search for endogenous factors regulating the peroxisomal compartment in normal liver, we treated female rats with dehydroepiandrosterone (DHEA) and 25-hydroxycholecalciferol for 1 and 6 days. Relative transcription levels of 39 selected genes were evaluated by real-time quantitative RT-PCR analysis. Catalase (peroxisomal marker)-specific activity was assayed in total liver homogenate and peroxisomes were visualized by catalase localization. DHEA induced peroxisome proliferation and raised catalase specific activity. Expression levels of 16 (of which 11 were peroxisomal) genes were altered. Pex 11, acyl-CoA oxidase,l - andd -multifunctional enzyme, thiolase 1, phytanoyl-CoA hydroxylase, 70 kDa peroxisomal membrane protein and very long chain acyl-CoA synthetase were upregulated, three others were downregulated. Vitamin D caused downregulation of six genes. Administration of vitamin D to peroxisomal disorder patients may be contraindicated. The adrenocortical hormone DHEA is a potential natural regulator of the peroxisomal compartment. Its therapeutic use in X-linked adrenoleukodystrophy, some other beta-oxidation defects and classical Refsum should be considered.
 ...
PMID:Modulation of the peroxisomal gene expression pattern by dehydroepiandrosterone and vitamin D: therapeutic implications. 1247 88