Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
23
pubmed:dateCreated
1992-9-10
pubmed:abstractText
The mechanism of FK506 immunosuppression has been proposed to proceed by formation of a tight-binding complex with the intracellular 12-kDa FK506-binding protein (FKBP12). The FK506-FKBP12 complex then acts as a specific high-affinity inhibitor of the intracellular protein phosphatase PP2B (calcineurin), interrupting downstream dephosphorylation events required for T-cell activation. Site-directed mutagenesis of many of the surface residues of FKBP12 has no significant effect on its affinity for calcineurin. We have identified, however, three FKBP12 surface residues (Asp-37, Arg-42, and His-87) proximal to a solvent-exposed segment of bound FK506 that may be direct contacts in the calcineurin complex. Site-directed mutagenesis of two of these residues decreases the affinity of FKBP12-FK506 for calcineurin (Ki) from 6 nM for wild-type FKBP12 to 3.7 microM for a R42K/H87V double mutant, without affecting the peptidylprolyl isomerase activity or FK506 affinity of the mutant protein. These FKBP12 mutations along with several substitutions on FK506 known to affect calcineurin binding form a roughly 100-A2 region of the FKBP12-FK506 complex surface that is likely to be within the calcineurin binding site.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
267
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
16029-32
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:1379588-Amino Acid Sequence, pubmed-meshheading:1379588-Animals, pubmed-meshheading:1379588-Binding Sites, pubmed-meshheading:1379588-Calcineurin, pubmed-meshheading:1379588-Calmodulin-Binding Proteins, pubmed-meshheading:1379588-Carrier Proteins, pubmed-meshheading:1379588-Humans, pubmed-meshheading:1379588-Models, Molecular, pubmed-meshheading:1379588-Molecular Conformation, pubmed-meshheading:1379588-Molecular Sequence Data, pubmed-meshheading:1379588-Molecular Weight, pubmed-meshheading:1379588-Mutagenesis, Site-Directed, pubmed-meshheading:1379588-Phosphoprotein Phosphatases, pubmed-meshheading:1379588-Protein Conformation, pubmed-meshheading:1379588-Sequence Homology, Nucleic Acid, pubmed-meshheading:1379588-Structure-Activity Relationship, pubmed-meshheading:1379588-Tacrolimus, pubmed-meshheading:1379588-Tacrolimus Binding Proteins
pubmed:year
1992
pubmed:articleTitle
Charged surface residues of FKBP12 participate in formation of the FKBP12-FK506-calcineurin complex.
pubmed:affiliation
Vertex Pharmaceuticals Inc., Cambridge, Massachusetts 02139-4211.
pubmed:publicationType
Journal Article, Comparative Study