The sequences appended to the amyloid core region of the HET-s prion protein determine higher-order aggregate organization in vivo
The sequences appended to the amyloid core region of the HET-s prion protein determine higher-order aggregate organization in vivo
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DOI：
10.1242/jcs.01116
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发表时间：
2004-05-15
影响因子：
4
通讯作者：
Saupe, SJ
中科院分区：
文献类型：
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作者：
Balguerie, A;Dos Reis, S;Saupe, SJ
真菌Podospora anserina的[Het-s]朊病毒作为HET-s蛋白的自我永存淀粉样蛋白形式繁殖。这种蛋白质在与HET-S蛋白（HET-s的等位基因变体）相互作用时触发称为异核体不相容性的细胞死亡反应。HET-s显示两个不同的结构域，N-末端球状结构域和C-末端非结构化朊病毒形成结构域（残基218-289）。在这里，我们描述了HETs（157-289）的特征，HETs是一种截短形式的HET-s，在球状结构域中具有广泛的缺失，但在不相容性和朊病毒繁殖中保留了完整的活性。在体外，HET（157-289）聚合成淀粉样蛋白纤维，显示与全长HET-s纤维相同的核心区域。我们先前已经证明，绿色荧光蛋白（GFP）与HET-s或HET-s（218-289）的融合物在体内转化为朊病毒状态时形成点状聚集体。相比之下，HET-s（157-289）/GFP融合蛋白在体内形成细长的纤维状聚集体。这种细长聚集体的长度可达150 μ m。这些有组织的结构在体内的动力学进行了分析，通过时间推移显微镜。我们发现，大的细长结构生长的横向协会较短的纤维状聚集体。当与HET-s（157-289）共表达时，全长HET-s和HET-s（218-289）可以掺入这样的伸长聚集体中。总之，我们的数据表明，HET-s（157-289）聚集体可以在体内采用有组织的高级结构，并且采用这种超分子组织的能力是由附加到淀粉样蛋白核心区域的序列赋予的。
The [Het-s] prion of the fungus Podospora anserina propagates as a self-perpetuating amyloid form of the HET-s protein. This protein triggers a cell death reaction termed heterokaryon incompatibility when interacting with the HET-S protein, an allelic variant of HET-s. HET-s displays two distinct domains, a N-terminal globular domain and a C-terminal unstructured prion-forming domain (residues 218-289). Here, we describe the characterization of HETs(157-289), a truncated form of HET-s bearing an extensive deletion in the globular domain but retaining full activity in incompatibility and prion propagation. In vitro, HETs(157-289) polymerizes into amyloid fibers displaying the same core region as full-length HET-s fibers. We have shown previously that fusions of green fluorescent protein (GFP) with HET-s or HET-s(218-289) form dot-like aggregates in vivo upon transition to the prion state. By contrast, a HET-s(157-289)/GFP fusion protein forms elongated fibrillar aggregates in vivo. Such elongated aggregates can reach up to 150 mum in length. The in vivo dynamics of these organized structures is analysed by time lapse microscopy. We find that the large elongate structures grow by lateral association of shorter fibrillar aggregates. When co-expressed with HET-s(157-289), full-length HET-s and HET-s(218-289) can be incorporated into such elongated aggregates. Together, our data indicate that HET-s(157-289) aggregates can adopt an organized higher-order structure in vivo and that the, ability to adopt this supramolecular organization is conferred by the sequences appended to the amyloid core region.