Naso R B, Karshin W L, Wu Y H, Arlinghaus R B
J Virol. 1979 Oct;32(1):187-98. doi: 10.1128/JVI.32.1.187-198.1979.
Under steady-state labeling conditions, Rauscher murine leukemia virus-infected NIH Swiss mouse cells contain at least three major polyproteins derived from the viral gag gene. They have molecular weights of 65,000, 40,000, and 25,000. They have been termed pPr65gag, Pr40gag, and pPr25gag. pPr65gag has been shown by a number of laboratories to be composed of all four core proteins (p15, pp12, p30, and p10). In this paper, Pr40gag was found to contain p30 and p10 antigenic determinants and peptide sequences, whereas pPr25gag was found to contain p15 and pp12. Pr40gag and pPr25gag are rapidly labeled precursor proteins that were detectable early in pulse-chase experiments. Both precursors disappeared during the later stages of the chase period concurrent with the appearance of the mature viral core proteins. pPr65gag and pPr25gag were found to be phosphorylated, pPr25 having a higher specific activity of 32P than pPr65. In spite of this, peptide mapping studies, as well as the identification of the phosphorylated amino acid residues of pPr65, and pPr25, and pp12, indicated that the same sites are phosphorylated regardless of whether the precursors or the mature pp12 are examined.
在稳态标记条件下，劳舍尔鼠白血病病毒感染的NIH瑞士小鼠细胞含有至少三种源自病毒gag基因的主要多蛋白。它们的分子量分别为65,000、40,000和25,000。它们被称为pPr65gag、Pr40gag和pPr25gag。许多实验室已证明pPr65gag由所有四种核心蛋白（p15、pp12、p30和p10）组成。在本文中，发现Pr40gag含有p30和p10抗原决定簇及肽序列，而pPr25gag含有p15和pp12。Pr40gag和pPr25gag是快速标记的前体蛋白，在脉冲追踪实验早期即可检测到。在追踪期后期，随着成熟病毒核心蛋白的出现，这两种前体蛋白均消失。发现pPr65gag和pPr25gag被磷酸化，pPr25的32P比活性高于pPr65。尽管如此，肽图谱研究以及对pPr65、pPr25和pp12磷酸化氨基酸残基的鉴定表明，无论检测的是前体蛋白还是成熟的pp12，磷酸化位点相同。
