van Pelt-Heerschap H, Verbeek H, Huisman M J, Sue Loesch-Fries L, Van Vloten-Doting L
Agrigenetics Advanced Research Laboratory, 5649 East Buckeye Road, Madison, Wisconsin 53716, USA.
Virology. 1987 Nov;161(1):190-7. doi: 10.1016/0042-6822(87)90185-1.
Three proteins, reacting specifically with sera raised against synthetic peptides identical to C-terminal amino acid sequences in alfalfa mosaic virus (AIMV) proteins P1, P2, and P3 translated in vitro from the AIMV RNAs 1, 2, and 3, respectively, were for the first time observed in tobacco and cowpea protoplasts. Part of P2 is post-translationally modified in protoplasts, because the anti-P2 serum reacted also with a protein migrating slower than P2 itself. The modification reported for P3 in infected tobacco leaves (T. Godefroy-Colburn et al. (1986) J. Gen. Virol. 67, 2233-2241) was observed in AIMV-infected bean leaves but not in AIMV-infected protoplasts and is apparently not essential for viral replication. Time course experiments showed that all nonstructural proteins could be detected 6 hr postinoculation. The two largest proteins P1 and P2 disappeared when virus production had reached a plateau, while the smallest nonstructural protein P3 remained at a constant level. Cell fractionation experiments showed that minus-strand RNA as well as all viral-encoded proteins were found in the 1000 g subcellular fraction. This location differs from the location of the nonstructural proteins in infected tobacco leaves (A. Berna et al. (1986) J. Gen. Virol. 67, 1135-1147).
首次在烟草和豇豆原生质体中观察到三种蛋白质，它们分别与针对从苜蓿花叶病毒（AIMV）RNA 1、2和3体外翻译的AIMV蛋白P1、P2和P3中与C末端氨基酸序列相同的合成肽产生的抗血清发生特异性反应。P2的一部分在原生质体中进行了翻译后修饰，因为抗P2血清也与一种迁移速度比P2本身慢的蛋白质发生反应。在感染AIMV的菜豆叶片中观察到了在感染烟草叶片中报道的P3修饰（T. Godefroy-Colburn等人（1986年）《病毒学杂志》67卷，2233 - 2241页），但在感染AIMV的原生质体中未观察到，并且这种修饰显然对病毒复制不是必需的。时间进程实验表明，接种后6小时可以检测到所有非结构蛋白。当病毒产量达到平台期时，两种最大的蛋白P1和P2消失，而最小的非结构蛋白P3保持在恒定水平。细胞分级分离实验表明，负链RNA以及所有病毒编码蛋白都存在于1000 g亚细胞组分中。这个位置与感染烟草叶片中非结构蛋白的位置不同（A. Berna等人（1986年）《病毒学杂志》67卷，1135 - 1147页）。
