Galarza J M, Sowa A, Hill V M, Skorko R, Summers D F
Department of Cellular, Viral and Molecular Biology, University of Utah School of Medicine, Salt Lake City 84132.
Virus Res. 1992 Jun;24(1):91-106. doi: 10.1016/0168-1702(92)90033-6.
Influenza A virus NP protein, the phosphoprotein associated with viral RNA in ribonucleoprotein (RNP) complexes, has been expressed at high levels (approximately 100 mg/liter cells) in insect (Sf9) cells by a baculovirus recombinant, and was localized almost entirely in the nuclei of these cells. NP was purified by immuno-affinity chromatography, and purified NP was shown to autophosphorylate and to phosphorylate casein in a cAMP-independent reaction. Furthermore, purified NP was able to bind to ssRNA as demonstrated by a mobility shift of ssRNA in non-denaturing gels. The binding of NP to ssRNA caused a diminution of its kinase activity in proportion to binding.
甲型流感病毒核蛋白（NP）是核糖核蛋白（RNP）复合物中与病毒RNA相关的磷蛋白，通过杆状病毒重组体在昆虫（Sf9）细胞中高水平表达（约100毫克/升细胞），并且几乎完全定位于这些细胞的细胞核中。NP通过免疫亲和层析进行纯化，纯化后的NP在不依赖cAMP的反应中显示出自身磷酸化以及对酪蛋白进行磷酸化的能力。此外，如非变性凝胶中ssRNA迁移率变化所示，纯化后的NP能够与单链RNA（ssRNA）结合。NP与ssRNA的结合导致其激酶活性按比例降低。
