Intracellular transport of SV40 large tumor antigen: a mutation which abolishes migration to the nucleus does not prevent association with the cell surface.
Intracellular transport of SV40 large tumor antigen: a mutation which abolishes migration to the nucleus does not prevent association with the cell surface.
复制标题
SV40 大肿瘤抗原的细胞内转运：消除向细胞核迁移的突变不会阻止与细胞表面的结合。
DOI：
10.1016/0042-6822(82)90074-5
复制
发表时间：
1982
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：
Lanford,RE;Butel,JS
SV40-腺病毒7杂交病毒PARA的cT突变，消除了SV40 t抗原（T-ag）向细胞核的转运，导致T-ag在感染和转化细胞的细胞质中积累。在PARA（cT）感染的猴细胞中检测了cT突变对T-ag与细胞表面关联的影响。通过免疫荧光、乳酸过氧化物酶催化的细胞表面碘化和细胞分离检测表面相关T-ag。与SV40和野生型PARA [PARA(nT)]感染的细胞相比，PARA（cT）感染的细胞表面碘化更容易标记表面相关T-ag。对照实验排除了PARA（cT）感染细胞中T-ag检测增强的可能性，这是由于细胞内T-ag被乳过氧化物酶标记或T-ag从死细胞泄漏并粘附在细胞表面所致。代谢标记和细胞分离证实了PARA（cT）感染细胞中表面相关T-ag水平升高，表明表面相关T-ag碘化增加是由于表面上T-ag多肽数量增加，而不是酪氨酸残基暴露增加。脉冲追踪实验表明，PARA（cT）感染细胞中表面相关T-ag水平升高并非由于表面相关T-ag的长期稳定性。cT突变为研究控制细胞内蛋白质运输的机制提供了一个有用的工具。
The cT mutation of PARA, an SV40-adenovirus 7 hybrid virus, abolishes the transport of SV40 T-antigen (T-ag) to the nucleus and results in the accumulation of T-ag in the cytoplasm of infected and transformed cells. The effect of the cT mutation on the association of T-ag with the cell surface was examined in PARA(cT)-infected monkey cells. Surface-associated T-ag was detected by immunofluorescence,lactoperoxidase-catalyzed cell-surface iodination, and cellular fractionation. Surface-associated T-ag was more readily labeled by cell-surface iodination with PARA(cT)-infected cells than with SV40 and wild-type PARA [PARA(nT)]-infected cells. Control experiments eliminated the possibility that the enhanced detection of T-ag in PARA(cT)-infected cells was due to the labeling of intracellular T-ag by lactoperoxidase or to T-ag leaking from dead cells and adhering to the cell surface. The elevated level of surface-associated T-ag in PARA(cT)-infected cells was confirmed by metabolic labeling and cellular fractionation, indicating that the increased iodination of surface-associated T-ag was due to a greater number of T-ag polypeptides on the surface rather than a greater exposure of tyrosine residues. Pulse-chase experiments demonstrated that the elevated level of surface-associated T-ag in PARA(cT)-infected cells was not due to a prolonged stability of surface-associated T-ag. The cT mutation provides a useful tool for studies of mechanisms governing intracellular protein transport.