PROTEIN IMPORT INTO NUCLEUS

蛋白质输入细胞核

• 批准号: 7722185
• 负责人: MICHAEL P ROUT
• 金额: $ 0.44万
• 依托单位: ROCKEFELLER UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-03-01 至 2009-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7722185
• 关键词: Affinity; Cell Nucleus; Cells; Computer Retrieval of Information on Scientific Projects Database; Cytoplasm; Cytoplasmic Protein; Funding; Grant; Institution; Karyopherins; Kinetics; Measures; Methods; Modeling; Nuclear Import; Nuclear Localization Signal; Nuclear Pore Complex; Process; Protein Import; Pump; Rate; Research; Research Personnel; Resources; Sampling; Source; United States National Institutes of Health; Yeasts; in vivo; insight

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Many cargoes destined for nuclear import carry nuclear localization signals that are recognized by karyopherins (Kaps). We present methods to quantitate import rates and measure Kap and cargo concentrations in single yeast cells in vivo, providing new insights into import kinetics. By systematically manipulating the amounts, types, and affinities of Kaps and cargos, we show that import rates in vivo are simply governed by the concentrations of Kaps and their cargo and the affinity between them. These rates fit to a straightforward pump-leak model for the import process. Unexpectedly, we deduced that the main limiting factor for import is the poor ability of Kaps and cargos to find each other in the cytoplasm in a background of overwhelming nonspecific competition, rather than other more obvious candidates such as the nuclear pore complex and Ran. It is likely that most of every import round is taken up by Kaps and nuclear localization signals sampling other cytoplasmic proteins as they locate each other in the cytoplasm.

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 许多用于核进口的货物携带核定位信号，这些信号被核转运蛋白（karyopherins，Kaps）识别。我们目前的方法来定量进口率和测量Kap和货物浓度在体内的单个酵母细胞，提供新的见解进口动力学。通过系统地操纵的数量，类型和亲和力的Kaps和货物，我们表明，在体内的进口率只是由Kaps和他们的货物和它们之间的亲和力的浓度。这些速率适合于进口过程的简单泵泄漏模型。出乎意料的是，我们推断输入的主要限制因素是Kaps和货物在压倒性非特异性竞争的背景下在细胞质中找到对方的能力差，而不是其他更明显的候选者，如核孔复合物和Ran。很可能每一轮输入的大部分都被Kaps占据，并且当其他细胞质蛋白在细胞质中相互定位时，核定位信号会对其他细胞质蛋白进行采样。