Abelson murine leukemia virus transformation-defective mutants with impaired P120-associated protein kinase activity
Abelson murine leukemia virus transformation-defective mutants with impaired P120-associated protein kinase activity
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P120 相关蛋白激酶活性受损的 Abelson 鼠白血病病毒转化缺陷突变体
DOI：
10.1128/jvi.36.2.374-386.1980
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发表时间：
1980
影响因子：
5.4
通讯作者：
J. Stephenson
中科院分区：
文献类型：
--
作者：
F. Reynolds;W. V. D. Van de Ven;J. Stephenson
描述了Abelson鼠白血病病毒（AbLV）的几种转化缺陷（td）突变体。细胞nonproductively感染这样的突变体表现出高度的生长接触抑制，未能在软琼脂中形成菌落，缺乏可挽救的转化病毒，和未感染的对照细胞一样容易转化野生型（wt）AbLV假型病毒。此外，发现分析的几个td AbLV非生产性感染的细胞克隆中的每一个在体内是非致瘤性的。td突变体AbLV感染的克隆的生化分析揭示了主要AbLV翻译产物P120和高度相关的80，000-Mr AbLV编码的蛋白P80的表达水平，其浓度类似于野生型AbLV转化的细胞中的浓度。尽管在td突变体AbLV感染的克隆中表达的AbLV特异性120，000-Mr多蛋白在分子量和[35 S]甲硫氨酸胰蛋白酶肽组成方面与wt AbLV转化系中的那些没有区别，但它们各自在其翻译后磷酸化模式方面与wt AbLV P120不同。先前描述的AbLV相关蛋白激酶活性显示识别作为底物的主要酪氨酸特异性受体位点，所述受体位点包含在AbLV P120和P80两者共有的单个良好分辨的胰蛋白酶肽内。在体外[γ-32 P] ATP介导的标记，这个磷酸化位点减少到低于检测水平，在td突变nonproductively感染的细胞克隆。这些发现证实了AbLV编码的多聚蛋白P120及其相关的蛋白激酶活性参与了AbLV肿瘤发生。
Several transformation-defective (td) mutants of Abelson murine leukemia virus (AbLV) are described. Cells nonproductively infected with such mutants exhibited a high degree of growth contact inhibition, failed to form colonies in soft agar, lacked rescuable transforming virus, and were as susceptible as uninfected control cells to transformation by wild-type (wt) AbLV pseudotype virus. In addition, each of several td AbLV nonproductively infected cell clones analyzed was found to be nontumorigenic in vivo. Biochemical analysis of td mutant AbLV-infected clones revealed levels of expression of the major AbLV translational product, P120, and a highly related 80,000-Mr AbLV-encoded protein, P80, at concentrations analogous to those in wt AbLV-transformed cells. Although the AbLV-specific 120,000-Mr polyproteins expressed in td mutant AbLV-infected clones were indistinguishable from those in wt AbLV-transformed lines with respect to molecular weight and [35S]methionine tryptic peptide composition, they each differed from wt AbLV P120 in their patterns of post-translational phosphorylation. A previously described AbLV-associated protein kinase activity is shown to recognize as substrate a major tyrosine-specific acceptor site(s) contained within a single well-resolved tryptic peptide common to both AbLV P120 and P80. In vitro [gamma-32P]ATP-mediated labeling of this phosphorylation site was reduced to below detectable levels in td mutant nonproductively infected cell clones. These findings establish that the AbLV-encoded polyprotein P120 and its associated protein kinase activity are involved in AbLV tumorigenesis.