Molecular cloning and expression of the murine interleukin-5 receptor.
Murine interleukin-5 (IL-5) is known to play an essential role in Ig production of B cells and proliferation and differentiation of eosinophils. Here, we have isolated cDNA clones encoding a murine IL-5 receptor by expression screening of a library prepared from a murine IL-5 dependent early B cell line. A cDNA library was expressed in COS7 cells and screened by panning with the use of anti-IL-5 receptor monoclonal antibodies. The deduced amino acid sequence analysis demonstrates that the receptor is a glycoprotein of 415 amino acids (Mr 45,284), including an N-terminal hydrophobic region (17 amino acids), a glycosylated extracellular domain (322 amino acids), a single transmembrane segment (22 amino acids) and a cytoplasmic tail (54 amino acids). COS7 cells transfected with the cDNA expressed a 60 kd protein that bound IL-5 with a single class of affinity (KD = 2-10 nM). FDC-P1 cells transfected with the cDNA for murine IL-5 receptor showed the expression of IL-5 binding sites with both low (KD = 6 nM) and high affinity (KD = 30 pM) and acquired responsiveness to IL-5 for proliferation, although parental FDC-P1 cells did not show any detectable IL-5 binding. In addition, several cDNA clones encoding soluble forms of the IL-5 receptor were isolated. Northern blot analysis showed that two species of mRNAs (5.0 kb and 5.8 kb) were detected in cell lines that display binding sites for murine IL-5. Homology search for the amino acid sequence of the IL-5 receptor reveals that the IL-5 receptor contains a common motif of a cytokine receptor family that is recently identified.
Takaki
S
S
Department of Biology, Kumamoto University Medical School, Japan.
Tominaga
A
A
Hitoshi
Y
Y
Mita
S
S
Sonoda
E
E
Yamaguchi
N
N
Takatsu
K
K
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000096:biosynthesis / Q000737:chemistry; D015870:Gene Expression; D015698:Genomic Library; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000737:chemistry; D051381:Rats; D011971:Receptors, Immunologic / Q000096:biosynthesis / Q000235:genetics*; D018123:Receptors, Interleukin; D053649:Receptors, Interleukin-5; D012995:Solubility; D014407:Tumor Cells, Cultured
D012333:RNA, Messenger; D011971:Receptors, Immunologic; D018123:Receptors, Interleukin; D053649:Receptors, Interleukin-5; D004247:DNA