Isolation of high-affinity murine interleukin 2 receptors as detergent-resistant membrane complexes.
Murine T cells and T cell lines bearing high- and low-affinity receptors for interleukin (IL) 2 were chemically cross-linked to radiolabeled IL 2 and subjected to differential detergent extractions to evaluate the extent of IL 2 receptor association with the nonionic detergent-resistant framework of the plasma membrane. Low-affinity receptors were readily solubilized by nonionic detergent extraction of whole cross-linked cells, while solubilization of high-affinity receptors required a stronger ionic detergent suggesting their association with a membrane structure that is resistant to nonionic detergents. To achieve physical separation of low- and high-affinity receptors, cells cross-linked to 125I-labeled IL 2 were centrifuged through a sucrose barrier containing Triton X-100. Alternatively, Triton X-114 extracts of plasma membrane fractions were partitioned into aqueous and detergent phases. By either approach, high-affinity receptors differed from low-affinity ones by their increased density and consisted of detergent-resistant complexes containing p55-p75 heterodimers. The low-affinity receptors, on the contrary, were of low density and consisted exclusively of detergent-soluble p55 subunits. High density and resistance to nonionic detergent extraction of high-affinity IL 2 receptors suggest their integration into lateral microdomains of the detergent-resistant framework of the plasma membrane.
Hoessli
D C
DC
Department of Pathology, Faculty of Medicine, University of Geneva, Switzerland.
Poincelet
M
M
Rungger-Brändle
E
E
D000818:Animals; D002458:Cell Fractionation; D002462:Cell Membrane / Q000378:metabolism; D002499:Centrifugation, Density Gradient; D003432:Cross-Linking Reagents; D003902:Detergents; D006801:Humans; D066298:In Vitro Techniques; D007376:Interleukin-2 / Q000378:metabolism; D008970:Molecular Weight; D017830:Octoxynol; D011092:Polyethylene Glycols; D015375:Receptors, Interleukin-2 / Q000302:isolation & purification* / Q000378:metabolism; D012967:Sodium Dodecyl Sulfate; D012995:Solubility; D013329:Structure-Activity Relationship
D003432:Cross-Linking Reagents; D003902:Detergents; D007376:Interleukin-2; D015375:Receptors, Interleukin-2; D012967:Sodium Dodecyl Sulfate; D011092:Polyethylene Glycols; D017830:Octoxynol; C010615:Nonidet P-40