Conversion of the interleukin 1 receptor antagonist into an agonist by site-specific mutagenesis.
Interleukin 1 (IL-1) receptor antagonist (IL-1ra) is a naturally occurring protein that binds to the IL-1 receptor present on T cells, fibroblasts, and other cell types and acts to block IL-1-induced responses. IL-1ra is a pure antagonist and has no agonist activity in in vitro or in vivo systems. By site-specific mutagenesis, an analog of IL-1ra was created that contained a substitution of a single amino acid, Lys-145----Asp. This analog, IL-1ra K145D, exhibited partial agonist activity in the D10.G4.1 cell proliferation assay. The newly acquired agonist activity could not be neutralized by antisera to IL-1 alpha or IL-1 beta, but it could be blocked by a monoclonal antibody to the T-cell IL-1 receptor. The analog also showed agonist activity as assayed by increased prostaglandin E2 synthesis from CHO cells expressing recombinant mouse IL-1 receptor. These results with IL-1ra K145D demonstrate the importance of the region surrounding the corresponding Asp-145 residue in IL-1 beta for triggering the biological response to IL-1.
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G
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Department of Molecular Genetics, Roche Research Center, Hoffmann-La Roche Inc., Nutley, NJ 07110.
Labriola-Tompkins
E
E
Campen
C A
CA
Benjamin
W R
WR
Karas
J
J
Plocinski
J
J
Biondi
D
D
Kaffka
K L
KL
Kilian
P L
PL
Eisenberg
S P
SP
D000818:Animals; D001224:Aspartic Acid; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D015232:Dinoprostone / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics; D006801:Humans; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1 / Q000378:metabolism*; D007700:Kinetics; D008239:Lysine; D051379:Mice; D016297:Mutagenesis, Site-Directed; D011506:Proteins / Q000235:genetics / Q000494:pharmacology*; D011971:Receptors, Immunologic / Q000187:drug effects / Q000502:physiology*; D017472:Receptors, Interleukin-1; D011994:Recombinant Proteins / Q000378:metabolism / Q000494:pharmacology; D012795:Sialoglycoproteins; D013601:T-Lymphocytes / Q000276:immunology; D014162:Transfection
C507763:IL1RN protein, human; C507764:Il1rn protein, mouse; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1; D011506:Proteins; D011971:Receptors, Immunologic; D017472:Receptors, Interleukin-1; D011994:Recombinant Proteins; D012795:Sialoglycoproteins; D001224:Aspartic Acid; D008239:Lysine; D015232:Dinoprostone