The conserved lymphokine element-0 in the IL5 promoter binds to a high mobility group-1 protein.
The conserved lymphokine elements-0 (CLE0) in the IL5 promoter is essential for the expression of IL-5. Here, we report the cloning and expression of a cDNA encoding a novel CLE0-binding protein, CLEBP-1 from a mouse Th2 clone, D10.G4.1. Interestingly, it was found that the CLEBP1 cDNA sequence was almost identical to the sequences of known high mobility group-1 (HMG1) cDNAs. When expressed as a recombinant fusion protein in Escherichia coli, CLEBP-1 was shown to bind to the IL5-CLE0 element in electrophoretic mobility-shift assays (EMSA) and southwestern blot analysis. The CLEBP-1 fusion protein cross-reacts with and-HMG-1/2 in Western blot analysis. It also binds to the CLE0 elements of IL4, GMCSF and GCSF genes. CLEBP-1 and closely related HMG-1 and HMG-2 proteins may play key roles in facilitating the expression of the lymphokine genes that contain CLE0 elements.
Marrugo
J
J
Division of Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore, MD 21224, U.S.A.
Marsh
D G
DG
Ghosh
B
B
D000818:Animals; D003001:Cloning, Molecular; D017124:Conserved Sequence / Q000276:immunology*; D018076:DNA, Complementary / Q000032:analysis; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000378:metabolism*; D006609:High Mobility Group Proteins / Q000378:metabolism*; D015848:Interleukin-5 / Q000235:genetics* / Q000378:metabolism*; D008222:Lymphokines / Q000235:genetics*; D051379:Mice; D011401:Promoter Regions, Genetic / Q000276:immunology*; D011485:Protein Binding / Q000276:immunology; D013945:Thymoma; D014407:Tumor Cells, Cultured
D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D006609:High Mobility Group Proteins; D015848:Interleukin-5; D008222:Lymphokines