THE ROLE OF THE NUCLEAR ENVELOPE IN INTRACELLULAR PROTEIN SORTING

蛋白质定位于细胞核的机制和蛋白质在细胞内的定位机制， 正在研究分泌途径的各种细胞器。 使用 它是水泡性口炎病毒（VSV）的温度敏感突变体， 可以同步单个细胞的细胞内转运， 病毒的糖蛋白（G蛋白）。 突变的G蛋白在 核被膜（NE）和粗面内质网（RER）在39 只有在32 ℃时才能通过分泌途径。 我们已经证明，NE不是G的运输所必需的。 蛋白 使用仅识别胞质结构域的抗血清， 这种跨膜蛋白，它所到达的细胞器可能是 通过免疫亲和分离技术纯化。 SV-40的大T抗原是病毒编码的蛋白质， 在细胞质中合成，但几乎只在细胞核中发现 感染的细胞。 主要的顺序要求，允许这一点， 最近已经定义了本地化。 由这种蛋白质组成的短肽 序列已被用来产生抗血清的核 大T抗原的定位序列，并被用来尝试 以确定参与蛋白质易位到 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.