Department of Molecular and Cellular Biochemistry, The Ohio State University, Columbus, OH 43210, USA.
Nucleic Acids Res. 2012 Jan;40(2):660-9. doi: 10.1093/nar/gkr781. Epub 2011 Sep 29.
Somatic nuclear autoantigenic sperm protein (sNASP) is a human homolog of the N1/N2 family of histone chaperones. sNASP contains the domain structure characteristic of this family, which includes a large acidic patch flanked by several tetratricopeptide repeat (TPR) motifs. sNASP possesses a unique binding specificity in that it forms specific complexes with both histone H1 and histones H3/H4. Based on the binding affinities of sNASP variants to histones H1, H3.3, H4 and H3.3/H4 complexes, sNASP uses distinct structural domains to interact with linker and core histones. For example, one of the acidic patches of sNASP was essential for linker histone binding but not for core histone interactions. The fourth TPR of sNASP played a critical role in interactions with histone H3/H4 complexes, but did not influence histone H1 binding. Finally, analysis of cellular proteins demonstrated that sNASP existed in distinct complexes that contained either linker or core histones.
体细胞核自身抗原性精子蛋白 (sNASP) 是人类组蛋白伴侣 N1/N2 家族的同源物。sNASP 包含该家族的特征结构域，包括由几个四肽重复 (TPR) 基序包围的大酸性斑。sNASP 具有独特的结合特异性，因为它与组蛋白 H1 和 H3/H4 形成特异性复合物。基于 sNASP 变体与组蛋白 H1、H3.3、H4 和 H3.3/H4 复合物的结合亲和力，sNASP 使用不同的结构域与连接子和核心组蛋白相互作用。例如，sNASP 的一个酸性斑对于连接子组蛋白结合是必需的，但对于核心组蛋白相互作用不是必需的。sNASP 的第四个 TPR 在与组蛋白 H3/H4 复合物的相互作用中起着关键作用，但不影响组蛋白 H1 结合。最后，对细胞蛋白的分析表明，sNASP 存在于含有连接子或核心组蛋白的不同复合物中。
