Influence of a steroid receptor DNA-binding domain on transcriptional regulatory functions.
We have isolated two independent mutations in the DNA-binding domain of the rat glucocorticoid receptor, P493R and S459A, that implicate DNA binding in the control of attached transcriptional activation domains, either that of the receptor itself or of VP16. The mutants are capable of activating transcription normally, but unlike wild-type receptors, they interfere with particular transcriptional activators in yeast and mammalian cells, and inhibit growth when overexpressed in yeast. The mutant residues reside at positions within the three-dimensional structure of the receptor that could, in principle, transduce structural changes from the DNA-binding surface of the receptor to other functional domains. These findings, together with the salt dependence of specific and nonspecific DNA binding by these receptors, suggest that specific DNA acts as an allosteric effector that directs the functional interaction of the receptor with targets of transcriptional activation and that the P493R and S459A mutants mimic the allosteric effect of specific DNA, allowing the receptor to interact with regulatory targets even in the absence of specific DNA binding.
Lefstin
J A
JA
Department of Pharmacology, University of California at San Francisco 94143-0450.
Thomas
J R
JR
Yamamoto
K R
KR
D000494:Allosteric Regulation; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D005075:Biological Evolution; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009690:Nucleic Acid Conformation; D010957:Plasmids; D017354:Point Mutation; D017433:Protein Structure, Secondary; D051381:Rats; D011965:Receptors, Glucocorticoid / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013724:Teratoma; D014158:Transcription, Genetic; D014162:Transfection; D014407:Tumor Cells, Cultured; D016335:Zinc Fingers
D017931:DNA Primers; D004268:DNA-Binding Proteins; D011965:Receptors, Glucocorticoid; D004247:DNA