Creation of "super" glucocorticoid receptors by point mutations in the steroid binding domain.
Almost all modifications of the steroid binding domain of glucocorticoid receptors are known to cause a reduction or loss of steroid binding activity. Nonetheless, we now report that mutations of cysteine 656 of the rat receptor, which was previously suspected to be a crucial amino acid for the binding process, have produced "super" receptors. These receptors displayed an increased affinity for glucocorticoid steroids and a decreased relative affinity for cross-reacting steroids such as progesterone and aldosterone. The increased in vitro affinity of the super receptors was maintained in a whole cell bioassay. These results indicate that additional modifications of the glucocorticoid receptor, and probably the other steroid receptors, may further increase the binding affinity and/or specificity.
Chakraborti
P K
PK
Steroid Hormones Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892.
Garabedian
M J
MJ
Yamamoto
K R
KR
Simons
S S
SS
D000818:Animals; D000911:Antibodies, Monoclonal; D001665:Binding Sites; D015153:Blotting, Western; D002460:Cell Line; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D003907:Dexamethasone / Q000494:pharmacology; D007700:Kinetics; D016297:Mutagenesis, Site-Directed; D011965:Receptors, Glucocorticoid / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013256:Steroids / Q000378:metabolism* / Q000494:pharmacology; D014162:Transfection
D000911:Antibodies, Monoclonal; D011965:Receptors, Glucocorticoid; D011993:Recombinant Fusion Proteins; D013256:Steroids; D003907:Dexamethasone; D015500:Chloramphenicol O-Acetyltransferase