THE ROLE OF THE NUCLEAR ENVELOPE IN INTRACELLULAR PROTEIN SORTING

允许蛋白质定位到细胞核和 分泌途径的各种细胞器正在研究中。vbl.使用 水疱性口炎病毒(VSV)的温度敏感突变体 可能使单细胞的细胞内传输同步 病毒的糖蛋白(G蛋白)。突变的G蛋白在体内积聚 核膜(NE)和粗面内质网(RER) 仅在32摄氏度时通过分泌途径进行。 我们已经证明，NE不是运输G所必需的 蛋白。使用的抗血清只识别细胞质域 这种跨膜蛋白，它被路由到的细胞器可能是 采用免疫亲和分离技术进行纯化。 SV-40的大T抗原是一种病毒编码的蛋白质， 在细胞质中合成，但几乎只在细胞核中发现 被感染的细胞。允许这样做的主要顺序要求 最近已经定义了本地化。由这个组成的短肽 序列已经被用来产生抗核的抗血清 大T抗原的定位序列，并正在被用于尝试 确定与蛋白质转位有关的分子 原子核。

The mechanisms which allows localization of proteins to the nucleus and the various organelles of the secretory pathway are under investigation. Using a temperature sensitive mutant of Vesicular Stomatitus Virus (VSV) it is possible to synchronize the intracellular transport of the single glycoprotein of the virus (G protein). The mutant G protein accumulates in the nuclear envelope (NE) and rough endoplasmic reticulum (RER) at 39 degrees C and only proceeds through the secretory pathway at 32 degrees C. We have demonstrated that the NE is not required for transport of G protein. Using an antisera which recognizes only the cytoplasmic domain of this transmembrane protein, the organelles to which it is routed may be purified by immunoaffinity isolation techniques. The large T antigen of SV-40 is a virally encoded protein which is synthesized in the cytoplasm yet is found almost exclusively in the nucleus of infected cells. The primary sequence requirements which allow this localization have recently been defined. Short peptides made up of this sequence have been used to generate antisera against the nuclear localization sequence of the large T antigen and are being used to attempt to identify the molecules involved in translocation of the protein to the nucleus.