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rdf:type |
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lifeskim:mentions |
umls-concept:C0007634,
umls-concept:C0008354,
umls-concept:C0040162,
umls-concept:C0043167,
umls-concept:C0079469,
umls-concept:C0089795,
umls-concept:C0279023,
umls-concept:C0441712,
umls-concept:C0596235,
umls-concept:C0851827,
umls-concept:C1515877,
umls-concept:C1701901,
umls-concept:C1879547
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pubmed:issue |
6
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pubmed:dateCreated |
1986-3-28
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pubmed:abstractText |
Numerous hormones are known to rapidly activate polyphosphoinositide turnover in target cells by promoting phosphodiesteratic cleavage of the phospholipids; however, little is known about the enzymology of receptor-mediated phosphoinositide breakdown. In the present study, thyrotropin-releasing hormone (TRH) stimulation of polyphosphoinositide turnover has been characterized in electrically permeabilized, [3H]myoinositol-labeled GH3 cells. The permeable cells allow the influence of small molecular weight (Mr less than or equal to 1000) cofactors to be determined. We present evidence for the following: 1) TRH stimulates inositol phosphate generation in permeable cells; 2) optimal hormone-stimulated inositol phosphate generation requires Mg2+, ATP, and Ca2+; 3) Mg2+ and ATP requirements reflect polyphosphoinositide kinase reactions; 4) in the absence of MgATP, TRH stimulates the phosphodiesteratic breakdown of pre-existing polyphosphoinositides in a reaction which requires only low Ca2+ (10(-7) M); 5) hormone activation is potentiated in the presence of the stable guanine nucleotide, GTP gamma S; neither TRH-stimulated nor GTP gamma S-potentiated hydrolysis is inhibited by cholera or pertussis toxin treatment. These results demonstrate that hormone-induced phospholipid hydrolysis involves activation of a phosphoinositide phosphodiesterase; activation results in lowering the Ca2+ requirement of the phosphodiesterase such that maximal activity is observed at Ca2+ levels characteristic of a resting cell (10(-7) M). Furthermore, TRH regulation of polyphosphoinositide hydrolysis is modulated by guanine nucleotides; however, nucleotide regulation appears to involve a GTP-binding factor (Np) other than Ns or Ni.
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pubmed:grant |
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pubmed:language |
eng
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pubmed:journal |
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pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Adenine Nucleotides,
http://linkedlifedata.com/resource/pubmed/chemical/Adenosine Triphosphate,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium,
http://linkedlifedata.com/resource/pubmed/chemical/Cholera Toxin,
http://linkedlifedata.com/resource/pubmed/chemical/Guanosine 5'-O-(3-Thiotriphosphate),
http://linkedlifedata.com/resource/pubmed/chemical/Guanosine Triphosphate,
http://linkedlifedata.com/resource/pubmed/chemical/Inositol Phosphates,
http://linkedlifedata.com/resource/pubmed/chemical/Lithium,
http://linkedlifedata.com/resource/pubmed/chemical/Pertussis Toxin,
http://linkedlifedata.com/resource/pubmed/chemical/Phosphoinositide Phospholipase C,
http://linkedlifedata.com/resource/pubmed/chemical/Phosphoric Diester Hydrolases,
http://linkedlifedata.com/resource/pubmed/chemical/Protein Kinases,
http://linkedlifedata.com/resource/pubmed/chemical/Thionucleotides,
http://linkedlifedata.com/resource/pubmed/chemical/Thyrotropin-Releasing Hormone,
http://linkedlifedata.com/resource/pubmed/chemical/Virulence Factors, Bordetella
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pubmed:status |
MEDLINE
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pubmed:month |
Feb
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pubmed:issn |
0021-9258
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:day |
25
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pubmed:volume |
261
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
2918-27
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pubmed:dateRevised |
2009-11-19
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pubmed:meshHeading |
pubmed-meshheading:3005271-Adenine Nucleotides,
pubmed-meshheading:3005271-Adenosine Triphosphate,
pubmed-meshheading:3005271-Animals,
pubmed-meshheading:3005271-Calcium,
pubmed-meshheading:3005271-Cell Line,
pubmed-meshheading:3005271-Cell Membrane Permeability,
pubmed-meshheading:3005271-Cholera Toxin,
pubmed-meshheading:3005271-Dose-Response Relationship, Drug,
pubmed-meshheading:3005271-Electric Stimulation,
pubmed-meshheading:3005271-Enzyme Activation,
pubmed-meshheading:3005271-Guanosine 5'-O-(3-Thiotriphosphate),
pubmed-meshheading:3005271-Guanosine Triphosphate,
pubmed-meshheading:3005271-Hydrolysis,
pubmed-meshheading:3005271-Inositol Phosphates,
pubmed-meshheading:3005271-Lithium,
pubmed-meshheading:3005271-Pertussis Toxin,
pubmed-meshheading:3005271-Phosphoinositide Phospholipase C,
pubmed-meshheading:3005271-Phosphoric Diester Hydrolases,
pubmed-meshheading:3005271-Pituitary Neoplasms,
pubmed-meshheading:3005271-Protein Kinases,
pubmed-meshheading:3005271-Rats,
pubmed-meshheading:3005271-Thionucleotides,
pubmed-meshheading:3005271-Thyrotropin-Releasing Hormone,
pubmed-meshheading:3005271-Virulence Factors, Bordetella
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pubmed:year |
1986
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pubmed:articleTitle |
Thyrotropin-releasing hormone activates a Ca2+-dependent polyphosphoinositide phosphodiesterase in permeable GH3 cells. GTP gamma S potentiation by a cholera and pertussis toxin-insensitive mechanism.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
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