Sun J M, Chen H Y, Davie J R
Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Manitoba, Winnipeg, Canada.
J Cell Biochem. 1994 Jun;55(2):252-63. doi: 10.1002/jcb.240550212.
Chicken histone H5 is an H1-like linker histone that is expressed only in nucleated erythrocytes. The histone H5 promoter has binding sites for Sp1 (a high affinity site) and UPE-binding protein, while the 3' erythroid-specific enhancer has binding sites for Sp1 (one moderate and three weak affinity), GATA-1, and NF1. In this study we investigated whether trans-acting factors that bind to the chicken histone H5 promoter or enhancer are associated with adult chicken immature and mature erythrocyte nuclear matrices. We show that NF1, but not Sp1, GATA-1, or UPE-binding protein, is associated with the internal nuclear matrices of these erythroid cells. Further, we found that a subset of the NF1 family of proteins is bound to the mature erythrocyte nuclear matrix. These results suggest that in chicken erythrocytes NF1 may mediate an interaction between the histone H5 enhancer and the erythroid internal nuclear matrix. NF1 was also present in the internal nuclear matrices of chicken liver and trout liver. The observations of this study provide evidence that NF1 may have a role in a variety of cell types in targeting specific DNA sequences to the nuclear matrix.
鸡组蛋白H5是一种类H1连接组蛋白，仅在有核红细胞中表达。组蛋白H5启动子具有Sp1（一个高亲和力位点）和UPE结合蛋白的结合位点，而3'红系特异性增强子具有Sp1（一个中等亲和力和三个弱亲和力）、GATA-1和NF1的结合位点。在本研究中，我们调查了与鸡组蛋白H5启动子或增强子结合的反式作用因子是否与成年鸡未成熟和成熟红细胞核基质相关。我们发现，与这些红系细胞的内核基质相关的是NF1，而非Sp1、GATA-1或UPE结合蛋白。此外，我们发现NF1蛋白家族的一个亚群与成熟红细胞核基质结合。这些结果表明，在鸡红细胞中，NF1可能介导组蛋白H5增强子与红系内核基质之间的相互作用。NF1也存在于鸡肝和鳟鱼肝的内核基质中。本研究的观察结果提供了证据，表明NF1可能在多种细胞类型中发挥作用，将特定DNA序列靶向核基质。
