Internalization of interleukin 2 is mediated by the beta chain of the high-affinity interleukin 2 receptor

J Exp Med. 1987 Apr 1;165(4):1201-6. doi: 10.1084/jem.165.4.1201.

Abstract

High-affinity IL-2-R correspond to a membrane receptor complex composed of two different IL-2-binding proteins, the Tac antigen (alpha chain) and a 70-75 kD beta chain. Using cell lines that express either the alpha or the beta protein, we demonstrate that IL-2 internalization occurs when ligand is bound to the isolated beta chain, but not when it is bound to the isolated alpha chain. The kinetics of IL-2 internalization mediated by the intermediate-affinity beta chain were nearly identical to those of the high-affinity alpha/beta heterodimer (t1/2 of 10-15 min), and each type of receptor targeted the bound IL-2 for intracellular degradation in lysosomes. The beta chain thus appeared to provide the essential element necessary for ligand internalization by both types of IL-2-R.

MeSH terms

  • Animals
  • Antigens, Surface / metabolism*
  • Endocytosis
  • Humans
  • Hylobates
  • Interleukin-2 / metabolism*
  • Kinetics
  • Protein Binding
  • Receptors, Immunologic / metabolism*
  • Receptors, Interleukin-2
  • Tumor Necrosis Factor Receptor Superfamily, Member 7

Substances

  • Antigens, Surface
  • Interleukin-2
  • Receptors, Immunologic
  • Receptors, Interleukin-2
  • Tumor Necrosis Factor Receptor Superfamily, Member 7