The function of RCC1/Ran complex.

RCC1/Ran 复合物的功能。

• 批准号: 05044134
• 负责人: NISHIMOTO Takeharu
• 金额: $ 1.92万
• 依托单位: Kyushu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for international Scientific Research
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 无数据
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-05044134/
• 关键词: RCC1; Ran; Eukaryotic Nuclei; G-protein; GNRF-activity; Alanine-scanning; cell cycle; tsBN2

The RCC1 gene was cloned as the human gene complementing tsBN2 cells, a temperature sensitive(ts)mutant of the BHK21 cell line derived from golden hamsters which show the cell cycle defect ; G1 arrest, and premature initiation of mitosi at the restrictive temperature. Its homologes have been isolated from both buddings (SRM1/PRP20/MTR1)and fission yeasts(pim1)and Drosophila(BJ1)in addition to hamster and Xenopus RCC1. Bischoff and Ponstingle have shown that RCC1 function as GNRP(Duanine nucleotide releasing protein)on the nuclear small G protein, Ran/TC4. According to the model of G protein, it pick up a signal from the receptor, in case of a signal transduction from the cell surface, and transfer to the downstream. Thus, some factors corresponding to the receptor should locate upstream of the RCC1/Ran system. The idea that such factor may be DNA molecule is very interesting and apparently reasonable, since RCC1 locates on chromosome abundantly ; one RCC1 molecule per one to ten nucleo … More somes. Our model is the following. The replication state of DNA molecule, such as ; its initiation, elongation and completion, will be transfer through the RCC1 : Ran system to the downstream, including a regulator of MPF, a central cell cycle engine. Based on this model, we suppose that the RCC1 has at least two domains : to bind with the chromosome or with Ran/TC4. These binding domains should locate in the repeat, since the RCC1 protein deleted in the N-terminal side outside of the repeat did complement tsBN2 cells. The identification of such a domain in the RCC1 will be a key step to clarify the function of the RCC1/Ran system on the cell cycle. Thus, we made the RCC1 mutants according to the alanine scanning method. Since in tsBN2 cells, endogeous RCC1 proteins disappear due to the mutation at 39.5ﾟC, we could investigate the functions of mutated RCC1, in vivo, by constructing transformants of tsBN2 cells expressing mutated RCC1 protein. We found that the GNRF activity of mutated RCC1 is correlated with its ability complimentating tsBN2 cells. Less

RCC1基因是与金黄地鼠BHK21细胞系的温度敏感(Ts)突变体tsBN2细胞互补的人类基因，在限制性温度下表现为细胞周期缺陷、G1期停滞和过早启动有丝分裂。除了从仓鼠和非洲爪哇RCC1中分离到它的同源物外，还从芽生酵母(SRM1/PRP20/MTR1)、分裂酵母(Pim1)和果蝇(BJ1)中分离出了它的同源物。Bischoff和Ponstingle已经证明RCC1在核小G蛋白RAN/TC4上作为GNRP(Duanine核苷酸释放蛋白)发挥作用。根据G蛋白的模型，在细胞表面信号转导的情况下，它从受体那里获得信号，并转移到下游。因此，与受体相对应的一些因子应该位于RCC1/RAN系统的上游。这种因素可能是dna分子的想法是非常有趣的，而且显然是合理的，因为rcc1丰富地位于染色体上；每一到十个核…中就有一个rcc1分子。再来点。我们的模式如下。DNA分子的复制状态，如其起始、延长和完成，将通过RCC1：RAN系统转移到下游，包括中央细胞周期引擎MPF的调节因子。基于这个模型，我们推测RCC1至少有两个结构域：与染色体结合或与RAN/TC4结合。这些结合结构域应该位于重复序列中，因为在重复序列外的N-末端缺失的RCC1蛋白确实补充了tsBN2细胞。在RCC1中识别这样一个结构域将是阐明RCC1/RAN系统在细胞周期中功能的关键一步。因此，我们根据丙氨酸扫描的方法获得了RCC1突变体。在tsBN_2细胞中，内源性RCC1蛋白由于在39.5C的突变而消失，因此我们可以通过构建表达突变的ﾟ_1蛋白的转化子来研究突变的RCC_1在体内的功能。我们发现突变的RCC1的GNRF活性与其对tsBN2细胞的互补能力有关。较少