BIODYNAMICS OF NUCLEAR MEMBRANE AND MATRIX

外膜蛋白质流动性和膜蛋白质不流动性的观察 大鼠肝细胞核的内膜表明，这些膜可能在 事实上是两个功能不同的隔间。 一个动态的外膜 可能是扩散途径的一部分，对核糖蛋白很重要 混合功能单加氧酶组分的生物合成和再分配 内质网（E.R.）和核隔间。 一 含有拓扑限制的非动态内核膜 蛋白质表明，这种膜在需要有机 蛋白质结构和稳定的多酶复合物，例如转录， 复制、mRNA易位。 未来的实验旨在追求 这些结果通过使用横向迁移率作为核结构的探针， 并作为一种手段来评估机制的有效性， 核内通讯 细胞色素P-450抗体和 P-450还原酶，两者都是外核膜蛋白，提供特异性 用于评价外膜作为二维组织的作用的标记物 细胞室之间的通讯途径。 内部调查 核膜将寻求探讨膜相关的作用 结构，例如核纤层蛋白、染色质和核糖核蛋白 内膜蛋白 能够特异性改变每种 膜相关组分，例如DNA酶I，微球菌核酸酶，RNA酶， 蛋白酶，盐，将被检查方面的影响， 迁移率 核扩散的另一个研究方向是 由核孔复合物介导的跨核膜转运。 模型葡聚糖化合物的核质转运速率和 将比较大小相等的核蛋白和非核蛋白。 这些研究可能有助于确定能量需求和蛋白质 三维结构或序列增强跨膜 运输 细胞核-细胞内 通信现在是可能的，因为观察到核 糖蛋白含有独特的寡糖部分。 以此为 标记，这将是可能的探索是否核膜和 细胞骨架糖蛋白在细胞核合成，或在细胞核后合成。 更传统的内质网-高尔基体途径。 人们希望 这些不同的方法将提供重要的新信息， 核结构的各个方面， 核-细胞内-质膜通讯。

The observation of protein mobility on the outer membrane and immobility on the inner membrane of rat liver nuclei suggests that these membranes may in fact be two functionally different compartments. A dynamic outer membrane may be part of a diffusion pathway, important for nuclear glycoprotein biosynthesis and redistribution of mixed function monooxygenase components between endoplasmic reticulum (E.R.) and nuclear compartments. A non-dynamic inner nuclear membrane containing topologically restrained proteins suggests a role for this membrane in processes requiring organic protein structures and stable multi-enzyme complexes, e.g. - transcription, replication, mRNA translocation. Future experiments are designed to pursue these results by using lateral mobility as a probe for nuclear structure, and as a means to evaluate the validity of mechanisms explaining nuclear-intracellular communication. Antibodies to cytochrome P-450 and P-450 reductase, both outer nuclear membrane proteins, provide specific markers for evaluating the role of outer membrane as a two dimensional communication pathway between cell compartments. Investigations of inner nuclear membrane will seek to explore the role of membrane associated structures, e.g. lamins, chromatin, and ribonucleoproteins in anchoring inner membrane proteins. Substances capable of specifically altering each membrane associated component, e.g. DNAase I, micrococcal nuclease, RNAase, proteases, salts, will be examined with regard to effects on lateral mobility. Another aspect of nuclear diffusion to be investigated will be trans-nuclear membrane transport mediated by the nuclear pore complex. Rates of nucleocytoplasmic transport for model dextran compounds and nuclear and non-nuclear proteins of equivalent size will be compared. These investigations may help define energetic requirements and protein three dimensional structure or sequence that enhance transmembrane transport. A new biochemical perspective on nuclear-intracellular communication is now possible because of the observation that nuclear glycoproteins contain a unique oligosaccharide moiety. Using this as a marker it will be possible to explore whether nuclear membrane and cytoskeletal glycoproteins are synthesized at the nucleus or follow the more conventional endoplasmic reticulum-Golgi pathways. It is hoped that these diverse approaches will provide significant new information relating various aspects of nuclear structure to mechanisms of nuclear-intracellular-plasma membrane communication.