Identification and cellular distribution of distinct proteins forming human GM-CSF receptor.
Two proteins forming the receptor for human granulocyte-macrophage colony-stimulating factor (GM-CSF)1 were identified and characterized. One with apparent Mr of about 80,000 was defined as alpha-chain and has Kd of 0.7-2.8 nM. The other binding molecule with apparent Mr of about 135,000 was defined as beta-chain and is related to the high-affinity binding with Kd of 10-40 pM. The binding kinetic studies confirmed that the 125I-GM-CSF associated slower to and dissociated more rapidly from the alpha-chain than the beta-chain. The alpha-chain is expressed not only on hemopoietic cells but also on full-term placental tissues, choriocarcinoma cells, and other solid tumor cells. In contrast, the distribution of the beta-chain is restricted on hemopoietic cells. The alpha-chain probably corresponds to the low-affinity GM-CSF receptor whose cDNA has been cloned and sequenced.
Chiba
S
S
Department of Internal Medicine, Faculty of Medicine, University of Tokyo, Japan.
Shibuya
K
K
Piao
Y F
YF
Tojo
A
A
Sasaki
N
N
Matsuki
S
S
Miyagawa
K
K
Miyazono
K
K
Takaku
F
F
D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000378:metabolism*; D006412:Hematopoietic Stem Cells / Q000737:chemistry; D006801:Humans; D007700:Kinetics; D008970:Molecular Weight; D009363:Neoplasm Proteins / Q000032:analysis; D009928:Organ Specificity; D011485:Protein Binding; D016187:Receptors, Granulocyte-Macrophage Colony-Stimulating Factor / Q000032:analysis*; D014407:Tumor Cells, Cultured / Q000737:chemistry
D009363:Neoplasm Proteins; D016187:Receptors, Granulocyte-Macrophage Colony-Stimulating Factor; D016178:Granulocyte-Macrophage Colony-Stimulating Factor