Source:http://linkedlifedata.com/resource/pubmed/id/10464307
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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
36
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pubmed:dateCreated |
1999-10-7
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pubmed:abstractText |
AMP deaminase (AMPD) converts AMP to IMP and is a diverse and highly regulated enzyme that is a key component of the adenylate catabolic pathway. In this report, we identify the high affinity interaction between AMPD and phosphoinositides as a mechanism for regulation of this enzyme. We demonstrate that endogenous rat brain AMPD and the human AMPD3 recombinant enzymes specifically bind inositide-based affinity probes and to mixed lipid micelles that contain phosphatidylinositol 4,5-bisphosphate. Moreover, we show that phosphoinositides specifically inhibit AMPD catalytic activity. Phosphatidylinositol 4,5-bisphosphate is the most potent inhibitor, effecting pure noncompetitive inhibition of the wild type human AMPD3 recombinant enzyme with a K(i) of 110 nM. AMPD activity can be released from membrane fractions by in vitro treatment with neomycin, a phosphoinositide-binding drug. In addition, in vivo modulation of phosphoinositide levels leads to a change in the soluble and membrane-associated pools of AMPD activity. The predicted human AMPD3 sequence contains pleckstrin homology domains and (R/K)X(n)(R/K)XKK sequences, both of which are characterized phosphoinositide-binding motifs. The interaction between AMPD and phosphoinositides may mediate membrane localization of the enzyme and function to modulate catalytic activity in vivo.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Sep
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pubmed:issn |
0021-9258
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
3
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pubmed:volume |
274
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
25701-7
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:10464307-AMP Deaminase,
pubmed-meshheading:10464307-Amino Acid Sequence,
pubmed-meshheading:10464307-Animals,
pubmed-meshheading:10464307-Binding Sites,
pubmed-meshheading:10464307-Brain,
pubmed-meshheading:10464307-Enzyme Activation,
pubmed-meshheading:10464307-Humans,
pubmed-meshheading:10464307-Molecular Sequence Data,
pubmed-meshheading:10464307-Phosphatidylinositols,
pubmed-meshheading:10464307-Protein Binding,
pubmed-meshheading:10464307-Rats,
pubmed-meshheading:10464307-Sequence Alignment,
pubmed-meshheading:10464307-Substrate Specificity
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pubmed:year |
1999
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pubmed:articleTitle |
Regulation of AMP deaminase by phosphoinositides.
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pubmed:affiliation |
Departments of Neurobiology and Cell Biology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
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