TY - JOUR
T1 - Binding of interleukin 2 to its 75-kDa intermediate affinity receptor is sufficient to activate Na+/H+ exchange
AU - Mills, G. B.
AU - May, C.
N1 - Copyright:
Copyright 2004 Elsevier B.V., All rights reserved.
PY - 1987
Y1 - 1987
N2 - High affinity interleukin 2 (IL-2) binding sites are composed of two IL-2 binding molecules: one of 55 kDa, commonly called TaC, and another of 75 kDa. In the absence of the other IL-2-binding molecule, the 55-kDa molecule binds IL-2 with a relatively low affinity and the 75 kDa molecule binds IL-2 with an intermediate affinity. One of the earliest events following interaction of IL-2 with its receptor on the surface of cells is an increase in intracellular pH due to activation of the Na+/H+ antiport. In contrast to IL-2 induced proliferation of human IL-2-sensitive T cells, interaction of IL-2 with a low affinity binding site was sufficient to activate the Na+/H+ antiport. By determining the effect of IL-2 on cytosolic pH in cells that express one of the two IL-2-binding molecules in the absence of the other IL-2-binding molecule, we have demonstrated that interaction of IL-2 with the 75 kDa IL-2 binding molecule is sufficient to activate the Na+/H+ antiport and thus induce cytosolic alkalinization. This indicates that the 75-kDa IL-2-binding molecule, in the absence of the 55-kDa IL-2-binding molecule, forms a functional receptor that can transduce an activation signal across the cell membrane.
AB - High affinity interleukin 2 (IL-2) binding sites are composed of two IL-2 binding molecules: one of 55 kDa, commonly called TaC, and another of 75 kDa. In the absence of the other IL-2-binding molecule, the 55-kDa molecule binds IL-2 with a relatively low affinity and the 75 kDa molecule binds IL-2 with an intermediate affinity. One of the earliest events following interaction of IL-2 with its receptor on the surface of cells is an increase in intracellular pH due to activation of the Na+/H+ antiport. In contrast to IL-2 induced proliferation of human IL-2-sensitive T cells, interaction of IL-2 with a low affinity binding site was sufficient to activate the Na+/H+ antiport. By determining the effect of IL-2 on cytosolic pH in cells that express one of the two IL-2-binding molecules in the absence of the other IL-2-binding molecule, we have demonstrated that interaction of IL-2 with the 75 kDa IL-2 binding molecule is sufficient to activate the Na+/H+ antiport and thus induce cytosolic alkalinization. This indicates that the 75-kDa IL-2-binding molecule, in the absence of the 55-kDa IL-2-binding molecule, forms a functional receptor that can transduce an activation signal across the cell membrane.
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M3 - Article
C2 - 2826580
AN - SCOPUS:0023571193
SN - 0022-1767
VL - 139
SP - 4083
EP - 4087
JO - Journal of Immunology
JF - Journal of Immunology
IS - 12
ER -