Identification of a direct interaction between interleukin 2 and the p64 interleukin 2 receptor gamma chain.
The interleukin 2 receptor (IL-2R) consists of at least two subunits, alpha and beta, both of which can bind interleukin 2 (IL-2). Recent studies have demonstrated the existence of a third subunit, a 64-kDa molecule termed IL-2R gamma chain, and have suggested that gamma chain functions to regulate the rate of IL-2 dissociation from the receptor. In the present report we have addressed whether the gamma chain modulates IL-2R affinity by contributing contact sites for IL-2 binding. Using reagents that allow the IL-2R complex to be immunoprecipitated through the IL-2 molecule itself, we demonstrate the existence of a stable IL-2-IL-2R gamma-chain complex. These studies thus establish that the IL-2R gamma chain directly contributes to the IL-2-binding site, consistent with the hypothesis that gamma chain influences IL-2R affinity through its direct interaction with IL-2.
Voss
S D
SD
Department of Human Oncology, University of Wisconsin Clinical Sciences Center, Madison 53792.
Leary
T P
TP
Sondel
P M
PM
Robb
R J
RJ
D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D000939:Epitopes / Q000032:analysis; D006801:Humans; D007376:Interleukin-2 / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D008223:Lymphoma; D046911:Macromolecular Substances; D008961:Models, Structural; D008969:Molecular Sequence Data; D015375:Receptors, Interleukin-2 / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D013953:Thymus Neoplasms; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D000939:Epitopes; D007376:Interleukin-2; D046911:Macromolecular Substances; D015375:Receptors, Interleukin-2; D011994:Recombinant Proteins