Department of Biochemistry, University of Oulu, Oulu, Finland.
Sci Rep. 2012;2:899. doi: 10.1038/srep00899. Epub 2012 Nov 29.
Juxtanodin, also called ermin, is an F-actin-binding protein expressed by oligodendrocytes, the myelin-forming cells of the central nervous system. While juxtanodin carries a short conserved F-actin-binding segment at its C terminus, it otherwise shares no similarity with known protein sequences. We carried out a structural characterization of recombinant juxtanodin in solution. Juxtanodin turned out to be intrinsically disordered, as evidenced by conventional and synchrotron radiation CD spectroscopy. Small-angle X-ray scattering indicated that juxtanodin is a monomeric, highly elongated, unfolded molecule. Ensemble optimization analysis of the data suggested also the presence of more compact forms of juxtanodin. The C terminus was a strict requirement for co-sedimentation of juxtanodin with microfilaments, but juxtanodin had only mild effects on actin polymerization. The disordered nature of juxtanodin may predict functions as a protein interaction hub, although F-actin is its only currently known binding partner.
juxtapodin，也称为ermin，是少突胶质细胞（中枢神经系统中形成髓鞘的细胞）表达的一种 F-actin 结合蛋白。虽然 juxtanodin 在其 C 末端带有一个短的保守 F-actin 结合片段，但它与已知的蛋白质序列没有任何相似之处。我们对重组 juxtanodin 在溶液中的结构进行了表征。如常规和同步辐射 CD 光谱所示，juxtanodin 原来是无规卷曲的。小角度 X 射线散射表明 juxtanodin 是一种单体、高度伸长、无折叠的分子。对数据的集合优化分析还表明存在更紧凑形式的 juxtanodin。C 末端是 juxtanodin 与微丝共沉淀的严格要求，但 juxtanodin 对肌动蛋白聚合只有轻微的影响。juxtanodin 的无规卷曲性质可能预示着其作为蛋白质相互作用枢纽的功能，尽管 F-actin 是其目前已知的唯一结合伴侣。
