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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
44
|
| pubmed:dateCreated |
1995-12-21
|
| pubmed:abstractText |
Integrin-ligand interactions are known to be dependent on divalent cations, although the precise role of cations in ligand binding is still unclear. Using the interaction between alpha 5 beta 1 and fibronectin as a model system, we have performed a comprehensive analysis of the effects of Mn2+, Mg2+, and Ca2+ on ligand binding. Each cation had distinct effects on the ligand-binding capacity of alpha 5 beta 1:Mn2+ promoted high levels of ligand binding, Mg2+ promoted low levels of binding, and Ca2+ failed to support binding. Studies of the effects of different combinations of cations on ligand binding indicated that the cation-binding sites within alpha 5 beta 1 are not all identical, or of broad specificity, but instead each site shows a distinct preference for one or more cations. Ca2+ strongly inhibited Mn(2+)-supported ligand binding, but this inhibition was noncompetitive, suggesting that Ca2+ recognizes different cation-binding sites to Mn2+. In contrast, Ca2+ acted as a direct competitive inhibitor of Mg(2+)-supported ligand binding, implying that Ca2+ can displace Mg2+ from the integrin. However, low concentrations of Ca2+ greatly increased the apparent affinity of Mg2+ for its binding site, suggesting the existence of a distinct high affinity Ca(2+)-binding site. Taken together, our results imply that the ligand-binding capacity of alpha 5 beta 1 can be regulated in a complex manner through separate classes of binding sites for Mn2+, Mg2+, and Ca2+.
|
| pubmed:grant | |
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Calcium,
http://linkedlifedata.com/resource/pubmed/chemical/Cations, Divalent,
http://linkedlifedata.com/resource/pubmed/chemical/Fibronectins,
http://linkedlifedata.com/resource/pubmed/chemical/Ligands,
http://linkedlifedata.com/resource/pubmed/chemical/Magnesium,
http://linkedlifedata.com/resource/pubmed/chemical/Manganese,
http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Fibronectin
|
| pubmed:status |
MEDLINE
|
| pubmed:month |
Nov
|
| pubmed:issn |
0021-9258
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
3
|
| pubmed:volume |
270
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
26270-7
|
| pubmed:dateRevised |
2009-9-29
|
| pubmed:meshHeading |
pubmed-meshheading:7592835-Animals,
pubmed-meshheading:7592835-Binding Sites,
pubmed-meshheading:7592835-Calcium,
pubmed-meshheading:7592835-Cations, Divalent,
pubmed-meshheading:7592835-Cell Adhesion,
pubmed-meshheading:7592835-Cell Line,
pubmed-meshheading:7592835-Chromatography, Affinity,
pubmed-meshheading:7592835-Female,
pubmed-meshheading:7592835-Fibronectins,
pubmed-meshheading:7592835-Humans,
pubmed-meshheading:7592835-Kinetics,
pubmed-meshheading:7592835-Leukemia, Erythroblastic, Acute,
pubmed-meshheading:7592835-Leukocytes, Mononuclear,
pubmed-meshheading:7592835-Ligands,
pubmed-meshheading:7592835-Magnesium,
pubmed-meshheading:7592835-Manganese,
pubmed-meshheading:7592835-Placenta,
pubmed-meshheading:7592835-Pregnancy,
pubmed-meshheading:7592835-Rats,
pubmed-meshheading:7592835-Receptors, Fibronectin,
pubmed-meshheading:7592835-Tumor Cells, Cultured
|
| pubmed:year |
1995
|
| pubmed:articleTitle |
Regulation of integrin alpha 5 beta 1-fibronectin interactions by divalent cations. Evidence for distinct classes of binding sites for Mn2+, Mg2+, and Ca2+.
|
| pubmed:affiliation |
Wellcome Trust Centre for Cell-Matrix Research, School of Biological Sciences, University of Manchester, United Kingdom.
|
| pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
|