Garber E A, Hanafusa H
Proc Natl Acad Sci U S A. 1987 Jan;84(1):80-4. doi: 10.1073/pnas.84.1.80.
Two isolates of recovered avian sarcoma viruses (rASVs), rASV157 and rASV1702, transform cells in culture, but have greatly reduced in vivo tumorigenicity. The src proteins of rASV157 and rASV1702 have alterations within their NH2 termini, are not myristoylated, and have an altered subcellular localization. We have molecularly cloned and determined the nucleotide sequences of the src genes of rASV157 and rASV1702. We found that their src proteins have unusual NH2 termini: the rASV157 src protein NH2 terminus consists of 30 amino acids of the env signal peptide attached to Ser-6 of the src sequence, while the rASV1702 src protein NH2 terminus consists of 45 amino acids of the env signal peptide attached to Ala-76 of the src sequence. Expression of recombinant Rous sarcoma virus constructs containing the molecularly cloned rASV src genes produced src proteins with the same properties as those of the parental viruses. Our results suggest that the NH2-terminal structures are responsible for many unusual properties of the mutant src proteins.
两株恢复性禽肉瘤病毒（rASV），即rASV157和rASV1702，可在培养物中转化细胞，但体内致瘤性大大降低。rASV157和rASV1702的src蛋白在其NH2末端存在改变，未进行肉豆蔻酰化，且亚细胞定位发生改变。我们对rASV157和rASV1702的src基因进行了分子克隆并测定了其核苷酸序列。我们发现它们的src蛋白具有不寻常的NH2末端：rASV157的src蛋白NH2末端由与src序列的Ser-6相连的env信号肽的30个氨基酸组成，而rASV1702的src蛋白NH2末端由与src序列的Ala-76相连的env信号肽的45个氨基酸组成。含有分子克隆的rASV src基因的重组劳斯肉瘤病毒构建体的表达产生了具有与亲本病毒相同特性的src蛋白。我们的结果表明，NH2末端结构导致了突变src蛋白的许多异常特性。
