Rapoport A P, DiPersio J F
Department of Medicine, University of Rochester School of Medicine and Dentistry, NY 14642.
Gene. 1993 Dec 31;137(2):333-7. doi: 10.1016/0378-1119(93)90030-7.
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.
利用聚合酶链反应从KG-1白血病细胞中克隆出两个编码人白细胞介素-3受体α亚基（IL-3Rα）的部分cDNA。与已发表的TF-1白血病细胞IL-3Rα序列[北村等人，《细胞》66（1991）1165 - 1174]相比，这些cDNA的序列分析预测有两个单氨基酸（aa）变化。通过对第二组独立获得的cDNA进行序列分析证实了这些变化。在从正常CD34 +人骨髓细胞克隆的cDNA所编码的IL-3Rα中发现了相同的aa变化。连接来自KG-1细胞的部分cDNA产生了一个全长功能性IL-3Rα cDNA克隆。当这种突变受体与IL-3受体的β亚基在COS-7细胞中共表达时，细胞外“LSXWS”共有序列的缺失导致可检测到的[125I]IL-3结合完全丧失。
