Sequence analysis and functional studies of interleukin-3 receptor alpha subunit-encoding cDNAs amplified from KG-1 leukemic cells and normal human marrow.
Two partial cDNAs encoding the human interleukin-3 receptor alpha subunit (IL-3R alpha) were cloned from KG-1 leukemic cells using the polymerase chain reaction. Sequence analysis of these cDNAs predicted two single-amino-acid (aa) changes as compared with the published TF-1 leukemic cell IL-3R alpha sequence [Kitamura et al., Cell 66 (1991) 1165-1174]. These changes were confirmed by sequence analysis of a second set of independently derived cDNAs. Identical aa changes were found in the IL-3R alpha encoded by cDNAs cloned from normal CD34+ human marrow cells. Ligation of the partial cDNAs derived from KG-1 cells resulted in a full-length functional IL-3R alpha cDNA clone. Deletion of the extracellular 'LSXWS' consensus sequence resulted in complete loss of detectable [125I]IL-3 binding when this mutant receptor was co-expressed in COS-7 cells with the beta subunit of the IL-3 receptor.
Rapoport
A P
AP
Department of Medicine, University of Rochester School of Medicine and Dentistry, NY 14642.
DiPersio
J F
JF
D001483:Base Sequence; D001853:Bone Marrow / Q000378:metabolism*; D001854:Bone Marrow Cells; D002478:Cells, Cultured; D018076:DNA, Complementary; D006801:Humans; D007938:Leukemia; D008969:Molecular Sequence Data; D009154:Mutation; D016133:Polymerase Chain Reaction; D016185:Receptors, Interleukin-3 / Q000737:chemistry / Q000235:genetics*; D014407:Tumor Cells, Cultured
D018076:DNA, Complementary; D016185:Receptors, Interleukin-3