Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1993-4-16
pubmed:abstractText
Oligodendroglial cells express many specific proteins, such as myelin basic protein (MBP), which are physiologically phosphorylated by protein kinase C (PKC). Diacylglycerols are physiological activators of PKC and can be liberated from phospholipids by the direct receptor-mediated activation of phospholipase C (PL-C) or indirectly via the activation of phospholipase D (PL-D). In a well-characterized human oligodendroglioma (HOG) cell line, PL-C (measured by release of [3H]inositol phosphates) and PL-D (formation of [3H]myristoylated or palmitoylated phosphatidylethanol) were activated by both carbachol (blocked by pirenzepine, suggesting an M1 receptor) and histamine (H1 receptor) but not glutamate, bradykinin, or phenylephrine. PL-C stimulation by carbachol or histamine was completely inhibited by short-term treatment (< 30 min) with phorbol ester (TPA), a PKC activator. In contrast, PL-D activation by either carbachol or histamine was stimulated in additive fashion by TPA, suggesting at least two distinct mechanisms for PL-D activation. Down regulation of PKC by prolonged (24 hr) treatment with TPA reversed the inhibitory effects of TPA on PL-C and the stimulatory effects on PL-D. However, the PKC inhibitors H-7 and galactosylsphingosine did not inhibit the TPA-mediated stimulation of PLD while the less-specific PKC inhibitor, staurosporine, was only partially inhibitory. Preexposure of cells to carbachol, greatly reduced both PL-C and PL-D activation by carbachol, suggesting homologous desensitization. Time-course studies indicated that PL-D activation (10 sec or less) was at least as fast as PL-C activation, and the affinity of carbachol and histamine for the receptor coupled to either phospholipase (EC50 = 5-10 microM) was about the same.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0360-4012
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
34
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
324-30
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Regulation of phospholipase D activity in a human oligodendroglioma cell line (HOG).
pubmed:affiliation
Department of Pediatrics, University of Chicago, IL 60637.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.