title: Characterization of three related murine interleukin-3 surface receptor proteins.
abstract: Iodinated interleukin-3 (IL-3) can be covalently cross-linked to three specific surface glycoproteins with net molecular masses of 170, 140, and 65-70 kDa under conditions in which ligand internalization and degradation do not occur. These three proteins plus two additional non-ligand-binding proteins of 90 and 55 kDa can be purified by IL-3 affinity chromatography. Comparative two-dimensional analysis of the tryptic digests of these five proteins indicates that the ligand-binding proteins are highly related at the peptide level. Incubation of cells with 125I-IL-3 at 37 degrees C results in rapid time- and energy-dependent internalization and degradation of ligand. Under these conditions only the 140- and 65-70-kDa binding proteins, which can recycle to the surface after internalization, can be identified. The lability of the 170-kDa protein indicates that it may not recycle. Thus, an energy-dependent mechanism is responsible for internalization and may be necessary for any potential interconversion of the higher 170- or 140-kDa proteins to the lower 140- and/or 65-70-kDa binding proteins.
authors.affiliation: Johns Hopkins Oncology Center, Baltimore, Maryland 21231.
authors.forename: D A
authors.initials: DA
authors.lastname: Stevens
authors.forename: J
authors.initials: J
authors.lastname: Schreurs
authors.forename: J N
authors.initials: JN
authors.lastname: Ihle
authors.forename: W S
authors.initials: WS
authors.lastname: May
mesh_terms: D000345:Affinity Labels; D000818:Animals; D003486:Cyanides / Q000494:pharmacology; D003599:Cytoskeleton / Q000187:drug effects; D004705:Endocytosis / Q000187:drug effects; D007377:Interleukin-3 / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000737:chemistry* / Q000302:isolation & purification; D051379:Mice; D008970:Molecular Weight; D010449:Peptide Mapping; D016185:Receptors, Interleukin-3 / Q000737:chemistry* / Q000302:isolation & purification; D013696:Temperature
chemical_list: D000345:Affinity Labels; D003486:Cyanides; D007377:Interleukin-3; D008562:Membrane Glycoproteins; D016185:Receptors, Interleukin-3