Comparison of nonphosphorylated and phosphorylated species of polyomavirus major capsid protein VP1 and identification of the major phosphorylation region
Comparison of nonphosphorylated and phosphorylated species of polyomavirus major capsid protein VP1 and identification of the major phosphorylation region
复制标题
多瘤病毒主要衣壳蛋白VP1非磷酸化和磷酸化种类的比较及主要磷酸化区域的鉴定
DOI：
10.1128/jvi.48.1.206-217.1983
复制
发表时间：
1983
影响因子：
5.4
通讯作者：
R. Consigli
中科院分区：
文献类型：
--
作者：
D. G. Anders;R. Consigli
多瘤病毒的主要病毒体蛋白VP1由约六种等电点物质组成，命名为A至F。次要物质D、E和F被磷酸化，被认为是病毒受体。我们首先想要区分所有VP 1物种是否都是通过翻译后修饰从共同的氨基酸序列衍生而来，或者一个或多个物种是否包含由替代mRNA加工产生的改变的氨基酸序列区域。我们比较了VP1物种的详细肽图谱与特定的蛋白酶和放射性同位素标记的几种组合。这种方法使我们能够检查超过80%的预测VP1序列，包括氨基和羧基末端。我们没有发现任何VP1物种之间存在序列差异的证据。发现32Pi的特异性掺入对于所有磷酸化物质是相同的。通过肽图比较体内32Pi标记的D、E和F的磷酸化位点，结果表明它们是相同的。每个磷酸化的物种含有一个主要的磷酸肽和几个次要的磷酸肽。通过酸水解鉴定的主要磷酸氨基酸是磷酸苏氨酸，也存在磷酸丝氨酸。通过使用化学切割方法，我们将主要的磷酸化区域定位到VP1序列的中心部分。我们讨论了这个区域的一些功能，并将这些信息与磷酸化的功能影响。
The major virion protein of polyomavirus, VP1, consists of about six isoelectric species designated A through F. The minor species D, E, and F are phosphorylated and are thought to serve as viral receptors. We first wanted to distinguish whether all VP1 species are derived by post-translational modification from a common amino acid sequence or whether one or more of the species contain a region(s) of altered amino acid sequence resulting from alternate mRNA processing. We compared the VP1 species by detailed peptide mapping with several combinations of specific protease and radioisotopic labels. This approach enabled us to examine more than 80% of the predicted VP1 sequence, including the amino-and carboxy-termini. We found no evidence of sequence differences among any of the VP1 species. The specific incorporation of 32Pi was found to be the same for all of the phosphorylated species. Comparison of the phosphorylation sites of in vivo 32Pi-labeled D, E, and F by peptide mapping showed them to be identical. Each phosphorylated species contained a single major phosphopeptide and several minor phosphopeptides. The major phosphoamino acid, identified by acid hydrolysis, was phosphothreonine, with phosphoserine also present. By using chemical cleavage methods, we localized the major phosphorylation region to a central portion of the VP1 sequence. We discuss some features of this region and relate this information to functional implications of phosphorylation.