Research Institute of Microbial Diseases, Osaka University, Yamadaoka, Suita, Japan.
Genes Cells. 2011 May;16(5):545-56. doi: 10.1111/j.1365-2443.2011.01510.x. Epub 2011 Apr 1.
We report a new type of interaction between two yeast prion proteins, Sup35 and New1. New1 consists of an N-terminal prion region (New1N) and a C-terminal region homologous to a translation elongation factor with two ATP-binding motifs. Amyloid formation of the Sup35 prion region (Sup35NM) was accelerated by a small amount of sonicated New1N amyloid (New1N-seeds) to produce Sup35NM[New1] amyloid. New1N amyloid formation was accelerated by Sup35NM[New1]-seeds but not by spontaneously generated Sup35NM-seeds, indicating that the structural features of the New1N amyloid were transmitted via the Sup35NM amyloid. Surprisingly, full-length New1 broke the Sup35NM amyloid fibrils in an ATP-dependent manner. This activity of New1 was independent from Hsp104. It was lost by a mutation in the second ATP-binding motif, by the truncation of the N-terminal prion region of New1 and by the pre-incubation of New1 with New1N-seeds. When New1 was overproduced in yeast [PSI(+)] cells carrying GFP-fused Sup35NM, diverse morphological changes in fluorescent foci occurred. Thus, New1 potentially has a regulatory role in prion state in yeast, working independently of the Hsp104 system.
我们报告了两种酵母朊病毒蛋白Sup35 和 New1 之间的一种新型相互作用。New1 由一个 N 端朊病毒区（New1N）和一个与两个 ATP 结合基序的翻译延伸因子同源的 C 端区组成。少量超声处理的 New1N 淀粉样蛋白（New1N-种子）加速了 Sup35 朊病毒区（Sup35NM）的淀粉样形成，从而产生 Sup35NM[New1]淀粉样蛋白。New1N 淀粉样形成被 Sup35NM[New1]-种子加速，但不受自发产生的 Sup35NM-种子的影响，表明 New1N 淀粉样的结构特征通过 Sup35NM 淀粉样蛋白传递。令人惊讶的是，全长 New1 以 ATP 依赖性方式破坏 Sup35NM 淀粉样纤维。New1 的这种活性与 Hsp104 无关。它通过第二个 ATP 结合基序的突变、New1 N 端朊病毒区的截断以及 New1 与 New1N-种子的预孵育而丧失。当 New1 在携带 GFP 融合 Sup35NM 的酵母 [PSI(+)]细胞中过量产生时，荧光焦点发生了不同的形态变化。因此，New1 可能在酵母朊病毒状态中具有调节作用，与 Hsp104 系统独立工作。
