Structural comparisons of wild-type and nuclear transport-defective simian virus 40 large tumor antigens.
Structural comparisons of wild-type and nuclear transport-defective simian virus 40 large tumor antigens.
复制标题
野生型和核转运缺陷型猿猴病毒 40 种大肿瘤抗原的结构比较。
DOI：
10.1016/0042-6822(84)90282-4
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发表时间：
1984
期刊：
影响因子：
3.7
通讯作者：
Butel,JS
中科院分区：
文献类型：
--
作者：
Jarvis,DL;Lanford,RE;Butel,JS
帕拉（nT）是一种缺陷型SV 40-腺病毒7杂交病毒，其含有SV 40基因组的整个早期区域，并编码合成SV 40大肿瘤抗原（T-ag）。该杂交体的转运缺陷变体帕拉（cT）编码不被转运至细胞核但在细胞质中积累的T-ag。通过肽图谱比较从野生型（WT）SV 40-、帕拉（nT）-和帕拉（cT）-感染的细胞中提取的T-ags的结构。所有三种类型的T-ag进行了相当大的降解时，提取使用Tris缓冲Nonidet P-40在pH 8.0。向提取缓冲液中加入200 μM亮抑酶肽可显著抑制该降解。含甲硫氨酸的胰蛋白酶肽的比较显示T-ags之间没有差异，这表明它们的一级结构相似或相同。磷酸肽图谱显示SV 40和帕拉（nT）编码的T-ags之间没有差异。相比之下，帕拉（cT）编码的T-ag缺乏一个突出的磷酸肽，在其他两个。这种差异的磷酸化运输缺陷的可能相关性进行了讨论。
PARA(nT) is a defective SV40-adenovirus 7 hybrid virus which contains the entire early region of the SV40 genome and codes for the synthesis of SV40 large tumor antigen (T-ag). A transport-defective variant of this hybrid, PARA(cT), encodes T-ag that is not transported to the nucleus, but accumulates in the cytoplasm. The structures of T-ags extracted from wild-type (WT) SV40-, PARA(nT)-, and PARA(cT)-infected cells were compared by peptide mapping. All three types of T-ag underwent considerable degradation when extracted using Tris-buffered Nonidet P-40 at pH 8.0. The addition of 200 μM leupeptin to the extraction buffer significantly inhibited this degradation. Comparison of methionine-containing tryptic peptides revealed no differences among the T-ags, suggesting that their primary structures are similar or identical. Phosphopeptide mapping revealed no differences between SV40- and PARA(nT)-encoded T-ags. In contrast, PARA(cT)-encoded T-ag lacked a prominent phosphopeptide that was present in both of the others. The possible relevance of this difference in phosphorylation to the transport defect is discussed.