ALTERNATE SPLICING IN A PARVOVIRAL NONSTRUCTURAL GENE LINKS A COMMON AMINO-TERMINAL SEQUENCE TO DOWNSTREAM DOMAINS WHICH CONFER RADICALLY DIFFERENT LOCALIZATION AND TURNOVER CHARACTERISTICS
ALTERNATE SPLICING IN A PARVOVIRAL NONSTRUCTURAL GENE LINKS A COMMON AMINO-TERMINAL SEQUENCE TO DOWNSTREAM DOMAINS WHICH CONFER RADICALLY DIFFERENT LOCALIZATION AND TURNOVER CHARACTERISTICS
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DOI：
10.1016/0042-6822(90)90512-p
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发表时间：
1990-08-01
期刊：
影响因子：
3.7
通讯作者：
TATTERSALL, P
中科院分区：
文献类型：
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作者：
COTMORE, SF;TATTERSALL, P
小鼠细小病毒（MVM）编码两组非结构蛋白，83-kDa NS-1多肽编码从一个连续的序列在基因组的左半部分和25-kDa NS-2多肽，共享一个共同的氨基末端结构域与NS-1，但多剪接。使用肽特异性抗体证明，当用MVM的原型菌株MVM（p）感染同步化A9细胞时，合成了NS-2的三种可变剪接形式，并且由于磷酸化和非磷酸化形式的存在，这些种类中的每一种在十二烷基硫酸钠凝胶电泳上以两条带迁移。虽然大多数NS-1分子位于细胞核中，但所有三种NS-2主要位于细胞质中，并且它们的磷酸化形式仅在细胞质中。尽管NS-1和NS-2分子在感染早期都被合成，但所有形式的NS-2的合成和积累速度是NS-1分子的三到四倍，使它们成为此时所有细胞中主要的病毒编码蛋白。尽管它们具有共同的氨基末端结构域，但NS-2分子迅速翻转，而NS-1多肽持续数小时。除了三种NS-2基因产物以不同的摩尔量合成的事实之外，我们无法检测到各种分子形式的表达、稳定性、分布或磷酸化的任何差异，这表明后者的这些特征是由它们共同的内部外显子介导的。
Minute virus of mice (MVM) encodes two groups of nonstructural proteins, the 83-kDa NS-1 polypeptides encoded from a contiguous sequence in the left half of the genome and the 25-kDa NS-2 polypeptides, which shares a common amino-terminal domain with NS-1 but are multiply spliced. Peptide-specific antibodies were used to demonstrate that three alternatively spliced forms of NS-2 are synthesized when synchronized A9 cells are infected with the prototype strain of MVM, MVM(p), and that each of these species migrates as two bands on sodium dodecyl sulfate-gel electrophoresis, due to the presence of both phosphorylated and unphosphorylated forms. While most NS-1 molecules are located in the nucleus, all three species of NS-2 are predominantely cytoplasmic, and their phosphorylated forms are exclusively cytoplasmic. Although both NS-1 and NS-2 molecules are synthesized early in infection, all forms of NS-2 are synthesized and accumulate three to four times as fast as NS-1 molecules, making them the predominant virally coded proteins in all the cell at this time. Despite their common amino-terminal domain, NS-2 molecules turn over rapidly while NS-1 polypeptides persist for many hours. Apart from the fact that the three NS-2 gene products are synthesized in different molar amounts, we were unable to detect any differences in the expression, stability, distribution, or phosphorylation of the various molecular forms, suggesting that these latter characteristics are mediated by their common internal exon.