Source:http://linkedlifedata.com/resource/pubmed/id/17785468
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
44
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pubmed:dateCreated |
2007-10-29
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pubmed:abstractText |
Adipocyte fatty acid-binding protein (AFABP/aP2) forms a physical complex with the hormone-sensitive lipase (HSL) and AFABP/aP2-null mice exhibit reduced basal and hormone-stimulated lipolysis. To identify the determinants affecting the interaction fluorescence resonance energy transfer (FRET) imaging was used in conjunction with a mutagenesis strategy to evaluate the roles AFABP/aP2 fatty acid binding and HSL phosphorylation have in complex formation as well as determine the HSL binding site on AFABP/aP2. The nonfatty acid binding mutant of AFABP/aP2 (R126Q) failed to form a FRET-competent complex with HSL either under basal or forskolin-stimulated conditions, indicating that lipid binding is required for association. Once bound to HSL and on the surface of the lipid droplet, YFP-AFABP/aP2 (but not YFP-HSL) exhibited energy transfer between the fusion protein and BODIPY-C12-labeled triacylglycerol. Serine to alanine mutations at the two PKA phosphorylation sites of HSL (659 and 660), or at the AMPK phosphorylation sites (565), blocked FRET between HSL and AFABP/aP2. Substitution of isoleucine for lysine at position 21 of AFABP/aP2 (K21I), but not 31 (K31I), resulted in a non-HSL-binding protein indicating that residues on helix alphaI of AFABP/aP2 define a component of the HSL binding site. These results indicate that the ligand-bound form of AFABP/aP2.interacts with the activated, phosphorylated HSL and that the association is likely to be regulatory; either delivering FA to inhibit HSL (facilitating feedback inhibition) or affecting multicomponent complex formation on the droplet surface.
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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 |
Nov
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pubmed:issn |
0021-9258
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
2
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pubmed:volume |
282
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
32424-32
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pubmed:meshHeading |
pubmed-meshheading:17785468-Adipocytes,
pubmed-meshheading:17785468-Amino Acid Substitution,
pubmed-meshheading:17785468-Animals,
pubmed-meshheading:17785468-Cell Line,
pubmed-meshheading:17785468-Cloning, Molecular,
pubmed-meshheading:17785468-Fatty Acid-Binding Proteins,
pubmed-meshheading:17785468-Fatty Acids,
pubmed-meshheading:17785468-Fluorescence Resonance Energy Transfer,
pubmed-meshheading:17785468-Humans,
pubmed-meshheading:17785468-Mice,
pubmed-meshheading:17785468-Models, Molecular,
pubmed-meshheading:17785468-Mutagenesis, Site-Directed,
pubmed-meshheading:17785468-Phosphorylation,
pubmed-meshheading:17785468-Recombinant Fusion Proteins,
pubmed-meshheading:17785468-Sterol Esterase
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pubmed:year |
2007
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pubmed:articleTitle |
Interaction of the adipocyte fatty acid-binding protein with the hormone-sensitive lipase: regulation by fatty acids and phosphorylation.
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pubmed:affiliation |
Department of Biochemistry, Molecular Biology, and Biophysics, Imaging Center, The University of Minnesota, Minneapolis 55455, USA.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't,
Research Support, N.I.H., Extramural
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