Wang Huanyu, Walsh Scott T R, Parthun Mark R
Department of Molecular and Cellular Biochemistry, The Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA.
Nucleic Acids Res. 2008 Oct;36(18):5763-72. doi: 10.1093/nar/gkn574. Epub 2008 Sep 9.
NASP (nuclear autoantigenic sperm protein) has been reported to be an H1-specific histone chaperone. However, NASP shares a high degree of sequence similarity with the N1/N2 family of proteins, whose members are H3/H4-specific histone chaperones. To resolve this paradox, we have performed a detailed and quantitative analysis of the binding specificity of human NASP. Our results confirm that NASP can interact with histone H1 and that this interaction occurs with high affinity. In addition, multiple in vitro and in vivo experiments, including native gel electrophoresis, traditional and affinity chromatography assays and surface plasmon resonance, all indicate that NASP also forms distinct, high specificity complexes with histones H3 and H4. The interaction between NASP and histones H3 and H4 is functional as NASP is active in in vitro chromatin assembly assays using histone substrates depleted of H1.
据报道，核自身抗原性精子蛋白（NASP）是一种H1特异性组蛋白伴侣。然而，NASP与N1/N2蛋白家族具有高度的序列相似性，该家族成员是H3/H4特异性组蛋白伴侣。为了解决这一矛盾，我们对人NASP的结合特异性进行了详细的定量分析。我们的结果证实，NASP可以与组蛋白H1相互作用，并且这种相互作用以高亲和力发生。此外，多项体外和体内实验，包括非变性凝胶电泳、传统和亲和层析分析以及表面等离子体共振，均表明NASP也与组蛋白H3和H4形成独特的、高特异性复合物。NASP与组蛋白H3和H4之间的相互作用具有功能性，因为NASP在使用不含H1的组蛋白底物进行的体外染色质组装试验中具有活性。
