Linked Life Data

10824686

Source:http://linkedlifedata.com/resource/pubmed/id/10824686

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2000-8-10
pubmed:abstractText
This study was undertaken to characterize the biochemical properties of rat pancreatic phospholipase D (PLD). Based on Western blot analysis of pancreas subcellular fractions, PLD1 was detected as a protein of 120 kDa associated with the microsomal fraction, whereas PLD2 appeared as a 105-kDa protein enriched in the microvesicular fraction. In these fractions, a low level of PLD activity was measured with an exogenous substrate containing phosphatidylinositol-4,5-bisphosphate (PIP2), unresponsive to guanosine triphosphate (GTP)gammaS and adenosine diphosphate (ADP)-ribosylation factor (ARF). Addition of unsaturated but not saturated fatty acids stimulated an oleate-dependent PLD activity that colocalized with the PLD1 enzyme in the crude plasma membrane and microsomal fractions. The transphosphatidylation reaction was maximal with either 200-400 mM (1.2-2.3%) ethanol or 25 mM (0.23%) 1-butanol, with an optimal pH between 6.5 and 7.2. Lipids extracted from the pancreatic membranes were potent inhibitors of the HL60 cell PLD activity when compared with those isolated from HL60 cells. Oleate-dependent PLD activity was less susceptible to these inhibitions. A phospholipase A1 (PLA1) activity hydrolyzing phosphatidylethanol also was found in the pancreatic membrane fractions and was nearly absent in the HL60 cells. This activity was completely inhibited by 400 nM tetrahydrolipstatin (THL), a lipase inhibitor. Pancreatic PLD1 and PLD2 activities could be measured after a chromatographic separation from microsomal membranes and high-speed supernatants, respectively. Activities of both enzymes were inhibited by oleate and required the presence of PIP2 in the substrate vesicles. ARF1 strongly activated PLD1 in a dose-dependent manner, and PLD2 was slightly responsive. Indirect immunofluorescence revealed that PLD2 is distributed throughout the pancreas, with a more intense staining in the islets. This study presents for the first time biochemical characteristics of the pancreatic PLD activities and shows the presence of oleate-dependent PLD1 and PLD2 activities, as well as PLD1 and PLD2 proteins in this gland.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0885-3177
pubmed:author
pubmed:issnType
Print
pubmed:volume
20
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
323-36
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed-meshheading:10824686-Animals, pubmed-meshheading:10824686-Cell Line, pubmed-meshheading:10824686-Cell Membrane, pubmed-meshheading:10824686-Enzyme Activation, pubmed-meshheading:10824686-Enzyme Inhibitors, pubmed-meshheading:10824686-Guanosine 5'-O-(3-Thiotriphosphate), pubmed-meshheading:10824686-Hydrogen-Ion Concentration, pubmed-meshheading:10824686-Immunohistochemistry, pubmed-meshheading:10824686-Isoenzymes, pubmed-meshheading:10824686-Microsomes, pubmed-meshheading:10824686-Molecular Weight, pubmed-meshheading:10824686-Oleic Acid, pubmed-meshheading:10824686-Pancreas, pubmed-meshheading:10824686-Phosphatidylinositol 4,5-Diphosphate, pubmed-meshheading:10824686-Phospholipase D, pubmed-meshheading:10824686-Phospholipases A, pubmed-meshheading:10824686-Phospholipases A1, pubmed-meshheading:10824686-Rats, pubmed-meshheading:10824686-Subcellular Fractions
pubmed:year
2000
pubmed:articleTitle
Subcellular distribution and characterization of rat pancreatic phospholipase D isoforms.
pubmed:affiliation
Service de Gastroentérologie, Département de Médecine, Faculté de Médecine, Université de Sherbrooke, Québec, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't