A restricted cytoplasmic region of IL-2 receptor beta chain is essential for growth signal transduction but not for ligand binding and internalization.
The functional, high affinity form of interleukin-2 receptor (IL-2R) is composed of two receptor components, the IL-2R alpha (p55) and IL-2R beta (p70-75) chains. Unlike the IL-2R alpha chain, the IL-2R beta chain contains a large cytoplasmic domain that shows no obvious tyrosine kinase motif. In the present study, we report the establishment of a system in which the cDNA-directed human IL-2R beta allows growth signal transduction in a mouse pro-B cell line. This system enabled us to identify a unique region within the cytoplasmic domain of the human IL-2R beta chain essential for ligand-mediated signal transduction. We also demonstrate that certain cytoplasmic deletion mutants in the IL-2R beta chain, although deficient in signal transduction, can still form high affinity IL-2R in conjunction with endogenous mouse IL-2R alpha chain; the mutants are still able to internalize the ligand as well.
Hatakeyama
M
M
Institute for Molecular and Cellular Biology, Osaka University, Japan.
Mori
H
H
Doi
T
T
Taniguchi
T
T
D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies; D001402:B-Lymphocytes; D001665:Binding Sites; D002455:Cell Division; D002460:Cell Line; D003593:Cytoplasm / Q000378:metabolism; D004261:DNA Replication; D006801:Humans; D007376:Interleukin-2 / Q000378:metabolism; D007700:Kinetics; D008024:Ligands; D046911:Macromolecular Substances; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D010957:Plasmids; D015375:Receptors, Interleukin-2 / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D015398:Signal Transduction; D014162:Transfection
D000906:Antibodies; D007376:Interleukin-2; D008024:Ligands; D046911:Macromolecular Substances; D015375:Receptors, Interleukin-2