Phi van L
Institute for Small Animal Research, Federal Research Center for Agriculture, Molecular Genetics Reseach Unit, Celle, Federal Republic of Germany.
Biochem J. 1996 Jan 1;313 ( Pt 1)(Pt 1):39-44. doi: 10.1042/bj3130039.
The lysozyme gene is expressed at a low level in myeloblasts and is progressively activated to constitutively high expression in mature macrophages. The binding activity of the newly defined NF-kappa B/Rel family of transcription factors increases during the terminal differentiation of macrophages. In this study, I show that NF-kappa B/Rel-like proteins bind to the nuclear factor kappa B (kappa B)-like sequence of the lysozyme promoter. These binding activities were induced by treatment of HD11 cells with lipopolysaccharide. Immunomobility shift assays show that c-Rel is possibly a factor in the complexes that bind to the kappa B-like sequence lys kappa B. Binding activity to one of the protein complexes seems to be regulated by phosphorylation. In fact, overexpression of p65 and c-Rel stimulates expression of the chloramphenicol acetyltransferase gene controlled by the lysozyme promoter. Furthermore, co-transfection experiments reveal that the kappa B-like sequence within the lysozyme promoter mediates the transactivation by p65 and c-Rel. These results indicate that the p65 and c-Rel could be components of the protein complexes that bind to the kappa B-like sequence and this binding could contribute to the progressively activated expression of the lysozyme gene during the terminal differentiation of macrophages.
溶菌酶基因在成髓细胞中低水平表达，并在成熟巨噬细胞中逐渐被激活至组成型高表达。新定义的转录因子NF-κB/Rel家族的结合活性在巨噬细胞终末分化过程中增加。在本研究中，我发现NF-κB/Rel样蛋白与溶菌酶启动子的核因子κB（κB）样序列结合。用脂多糖处理HD11细胞可诱导这些结合活性。免疫迁移率变动分析表明，c-Rel可能是与κB样序列lys κB结合的复合物中的一个因子。对其中一种蛋白质复合物的结合活性似乎受磷酸化调节。事实上，p65和c-Rel的过表达刺激了由溶菌酶启动子控制的氯霉素乙酰转移酶基因的表达。此外，共转染实验表明，溶菌酶启动子内的κB样序列介导了p65和c-Rel的反式激活。这些结果表明，p65和c-Rel可能是与κB样序列结合的蛋白质复合物的组成成分，这种结合可能有助于溶菌酶基因在巨噬细胞终末分化过程中逐渐被激活表达。
