Partial agonist/antagonist mouse interleukin-2 proteins indicate that a third component of the receptor complex functions in signal transduction.
Some mouse interleukin-2 (mIL-2) proteins with substitutions at residue Gln141 are unable to trigger a maximal biological response. The Asp141 protein induces the lowest maximal response. The Asp141 protein can weakly antagonize the biological activity of mIL-2 and strongly antagonizes the biological activity of active mIL-2 mutant proteins that have defects in interactions with the high affinity receptor. Residue 141 mutant proteins bind with reduced affinity to T cells expressing the high affinity IL-2 receptor, yet bind normally to transfected fibroblasts expressing only the alpha and beta chains of the receptor. These results suggest that a third receptor component is important for both binding and signal transduction.
Zurawski
S M
SM
Department of Molecular Biology, DNAX Research Institute, Palo Alto, CA 94304-1104.
Imler
J L
JL
Zurawski
G
G
D000818:Animals; D001224:Aspartic Acid; D001665:Binding Sites; D001667:Binding, Competitive; D003001:Cloning, Molecular; D005973:Glutamine; D007376:Interleukin-2 / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D007700:Kinetics; D015375:Receptors, Interleukin-2 / Q000187:drug effects / Q000502:physiology*; D015398:Signal Transduction / Q000187:drug effects; D013329:Structure-Activity Relationship
D007376:Interleukin-2; D015375:Receptors, Interleukin-2; D005973:Glutamine; D001224:Aspartic Acid