Faculty of Medicine, Institut für Virologie, Philipps-Universität Marburg, Hans-Meerweinstr, Marburg, Germany.
J Infect Dis. 2011 Nov;204 Suppl 3:S927-33. doi: 10.1093/infdis/jir319.
Phosphorylation of the Marburg virus nucleoprotein NP is distributed over 7 regions (I-VII) in its C-terminus. The exact localization of phosphorylated amino acids and function of NP phosphorylation are unknown. Here, we show that the major phosphate acceptor sites in NP region II are serine 446 and serines 453-455; the latter are located in a cluster of 6 serine residues (aa 450-455). The function of phosphorylation in region II was tested using an infectious virus-like particle assay. Phosphorylation influenced reporter gene activity that reflects viral transcription and replication. An NP mutant mimicking 3 phosphorylated serine residues at position 453-455 supported reporter gene activity better than wild-type NP. Negative charges at positions 450-452 and when the serine cluster was completely substituted by alanine inhibited reporter gene activity significantly. These data support the idea that phosphorylation of NP region II modulates viral RNA synthesis in transcription and/or replication.
马尔堡病毒核蛋白 NP 的磷酸化分布在其 C 末端的 7 个区域（I-VII）。磷酸化氨基酸的确切定位和 NP 磷酸化的功能尚不清楚。在这里，我们表明 NP 区域 II 中的主要磷酸受体位点是丝氨酸 446 和丝氨酸 453-455；后者位于 6 个丝氨酸残基（aa 450-455）的簇中。使用感染性病毒样颗粒测定法测试了区域 II 中的磷酸化功能。磷酸化影响反映病毒转录和复制的报告基因活性。模拟位置 453-455 的 3 个磷酸化丝氨酸的 NP 突变体比野生型 NP 支持报告基因活性更好。位置 450-452 的负电荷以及当丝氨酸簇完全被丙氨酸取代时，显著抑制报告基因活性。这些数据支持这样一种观点，即 NP 区域 II 的磷酸化调节转录和/或复制中的病毒 RNA 合成。
