Linked Life Data

8518748

Source:http://linkedlifedata.com/resource/pubmed/id/8518748

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1993-7-29
pubmed:abstractText
Proteins of the peroxisomal membrane can be schematically divided into two groups, one being made up of more or less characterized proteins with generally unknown functions and the other consisting of enzyme activities of which the corresponding proteins have not been characterized. In the present report, these proteins and enzymes are described with the addition of unpublished results regarding their induction by peroxisome proliferators at the post-transcriptional level. Integral membrane proteins (IMPs) can be isolated using an alkaline solution of sodium carbonate. A dozen of preponderant IMPs can be seen on sodium dodecyl sulfate polyacrylamide gel electrophoresis, and the major band corresponds to a 70 kDa IMP, of which the corresponding rat cDNA is known. Some IMPs have been characterized by immunoblot analysis. Recently, a cDNA has been cloned for a peroxisome assembly factor (35 kDa IMP). Functions have also been proposed for some IMPs but are not yet firmly settled. Some IMPs (450/520, 70 and 26 kDa) are strongly induced by peroxisome proliferators. Our results extend to cipro- and fenofibrate the observation that the 70 kDa IMP mRNA level is strongly increased in di(2-ethylhexyl)phtalate-treated rats. All the enzyme activities associated with the peroxisomal membrane are involved in lipid metabolism: activation of substrates (fatty acids), ether lipid biosynthesis, and formation of precursors (fatty alcohols). It is believed that the same long-chain acyl-CoA synthetase occurs in the peroxisome as well as in the outer mitochondrial membrane and the endoplasmic reticulum. However, two highly homologous but different cDNAs encoding rat liver and brain long-chain acyl-CoA synthetases have been isolated recently. Evidence has been accumulated for a distinct synthetase that specifically activates very-long chain fatty acids. The first two steps of ether lipid biosynthesis require dihydroxyacetone-phosphate (DHAP) acyltransferase and alkyl-DHAP synthetase, the active sites of which are located on the inner surface of the membrane. In contrast, the catalytic site of the acyl/alkyl-DHAP reductase, which generates sn-1-alkyl-glycerol-3-phosphate, is located on the outer surface. Long-chain fatty alcohols, which are obligate precursors of ether lipids and wax esters, are biosynthetized by the reduction of the corresponding acyl-CoAs via the action of an acyl-CoA reductase. Peroxisome proliferators do not appear to stimulate these enzyme activities specifically. However, we report that feno- and ciprofibrate treatments increase six-fold the palmitoyl-CoA synthetase mRNA level in the rat liver.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0248-4900
pubmed:author
pubmed:issnType
Print
pubmed:volume
77
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
89-104
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Proteins and enzymes of the peroxisomal membrane in mammals.
pubmed:affiliation
Laboratoire de Biologie Moléculaire et Cellulaire, Faculté des Sciences Mirande, Université de Bourgogne, Dijon, France.
pubmed:publicationType
Journal Article, Review, Research Support, Non-U.S. Gov't