Sun J M, Penner C G, Davie J R
Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Manitoba, Winnipeg, Canada.
FEBS Lett. 1993 Sep 27;331(1-2):141-4. doi: 10.1016/0014-5793(93)80313-j.
During the final stages of erythroid maturation, the expression of the chicken histone H5 gene ceases. The histone H5 promoter has binding sites for Sp1 and UPE-binding protein. The 3' histone H5 enhancer has binding sites for Sp1, GATA-1 and NF1. Here, we show that the DNA-binding activities of transcription factors Sp1 and GATA-1 is reduced 5- to 10-fold in mature cells, while the activities of UPE-binding protein and NF1 remain the same in mature and immature erythrocytes. The reduced activities of Sp1 and GATA-1 may contribute to the inactivation of the histone H5 gene in mature erythrocytes.
在红细胞成熟的最后阶段，鸡组蛋白H5基因的表达停止。组蛋白H5启动子具有Sp1和上游元件结合蛋白（UPE-binding protein）的结合位点。组蛋白H5的3'增强子具有Sp1、GATA-1和NF1的结合位点。在此，我们表明，转录因子Sp1和GATA-1的DNA结合活性在成熟细胞中降低了5至10倍，而UPE结合蛋白和NF1的活性在成熟和未成熟红细胞中保持不变。Sp1和GATA-1活性的降低可能导致成熟红细胞中组蛋白H5基因的失活。
