Structures of non-prion amyloids

我们已经研究了几种对各自生物体具有正常功能的非Prion淀粉样蛋白：PMel17，一种哺乳动物黑素细胞蛋白，正常情况下形成参与黑色素生物合成的淀粉样蛋白；以及Curli，一种参与黏附的大肠杆菌细胞表面淀粉样蛋白。我们发现，人PMel17的重复结构域能够形成一种淀粉样蛋白结构，该结构在黑素细胞典型的中等酸性pH下容易形成，并在中性pH(1)下迅速溶解。小鼠和斑马鱼的PMel17同源物的重复结构域几乎没有序列保守性，但确实保存了在黑素小体的酸性pH下形成淀粉样蛋白的能力(2)。我们用卷曲蛋白表征了淀粉样蛋白的形态，发现它们不在酵母蛋白淀粉样蛋白典型的寄存器内平行结构中(3)。与Frank Shewaker(USUHS)合作，我们还研究了发现聚集在肌萎缩侧索硬化症患者神经元胞浆中的FUS蛋白。我们发现FUS在酵母细胞中聚集，产生明显的生长抑制(4)。如同在ALS神经元中一样，当在酵母中共表达时，FUS倾向于与TDP-43共聚集(4)。 1.McGlinchey RP，Shewaker F，McPhie P，蒙特罗索B，瑟伯KR&Wickner RB(2009)黑素小体原纤维蛋白PMel17的重复结构域形成促进黑色素合成的淀粉样核。程序娜塔莉。阿卡德。SCI。美国106：13731-6。 2.McGlinchey，R.，Shewaker，F.，Hu，K.H.，McPhie，P.，Tycko，R.，Wickner，Rb(2011)黑素体基质蛋白PMel17的重复结构域在酸性黑素体pH下形成淀粉样纤维。J.Biol.化学。286：8385-93。 3.Shewaker F，McGlinchey R，Theber KR，McPhie P，Dyda F，Tycko R&Wickner RB(2009)功能性卷曲淀粉样蛋白不是基于寄存器内平行的β-折叠结构。J.Biol.化学。284：25065-25076。 4.在肌萎缩侧索硬化症酵母模型中，Kryndushkin DS、Wickner Rb、Shewaker F.fus/TLS形成细胞质聚集体，抑制细胞生长并与TDP-43相互作用。蛋白质细胞2011；2：223-36。

We have studied several non-prion amyloids that have normal functions for their respective organisms: Pmel17, a mammalian melanocyte protein that normally forms amyloid involved in melanin biosynthesis and curli, a cell-surface amyloid of E. coli that is involved in adhesion. We found that the repeat domain of human Pmel17 is able to form an amyloid structure that forms readily at the mildly acid pH typical of the melanocyte, and rapidly dissolves at neutral pH (1). The repeat domains of Pmel17 homologs from mouse and zebrafish have little conservation of sequence, but do conserve the ability to form amyloid specifically at the acid pH of the melanosome (2). We characterized the amyloid form by curli proteins and found that they are not in the in-register parallel architecture typical of the yeast prion amyloids (3). In collaboration with the Frank Shewmaker (USUHS), we also studied the FUS protein that is found aggregated in the cytoplasm of neurons of patients with amyotrophic lateral sclerosis. We found that FUS aggregates in yeast cells, producing a marked growth inhibition (4). As in ALS neurons, FUS tends to co-aggregate with TDP-43 when co-expressed in yeast (4). 1. McGlinchey RP, Shewmaker F, McPhie P, Monterroso B, Thurber KR & Wickner RB (2009) The repeat domain of the melanosome fibril protein Pmel17 forms the amyloid core promoting melanin synthesis. Proc. Natl. Acad. Sci. USA 106: 13731-6. 2. McGlinchey, R., Shewmaker, F., Hu, K. H., McPhie, P., Tycko, R., Wickner, RB (2011) Repeat domains of melanosome matrix protein Pmel17 orthologs form amyloid fibrils at the acidic melanosomal pH. J. Biol. Chem. 286: 8385-93. 3. Shewmaker F, McGlinchey R, Thurber KR, McPhie P, Dyda F, Tycko R & Wickner RB (2009) The functional curli amyloid is not based on in-register parallel beta-sheet structure. J. Biol. Chem. 284: 25065 - 25076. 4. Kryndushkin DS, Wickner RB, Shewmaker F. FUS/TLS forms cytoplasmic aggregates, inhibits cell growth and interacts with TDP-43 in a yeast model of amyotrophic lateral sclerosis. Protein Cell 2011; 2:223 - 36.