Nehrbass U, Blobel G
Laboratory of Cell Biology, Howard Hughes Medical Institute, Rockefeller University, New York 10021, USA.
Science. 1996 Apr 5;272(5258):120-2. doi: 10.1126/science.272.5258.120.
The nuclear import factor p10 was cloned from Saccharomyces cerevisiae and found to be essential. The protein p10 can bind directly to several peptide repeat-containing nucleoporins. It also binds to the guanosine triphosphatase (GTPase) Ran in its guanosine diphosphate (GDP)-bound form and to karyopherin beta. Assembly of the karyopherin heterodimer on immobilized nucleoporin yielded cooperative binding of p10 and Ran-GDP. Addition of GTP to this pentameric complex led to dissociation of karyopherin (chi, presumably via in situ formation of Ran-GTP from Ran-GDP. Thus, p10 appears to coordinate the Ran-dependent association and dissociation reactions underlying nuclear import.
核输入因子p10是从酿酒酵母中克隆出来的，发现它是必不可少的。蛋白质p10可以直接与几种含有肽重复序列的核孔蛋白结合。它还以其二磷酸鸟苷（GDP）结合形式与鸟苷三磷酸酶（GTPase）Ran以及核转运蛋白β结合。核转运蛋白异二聚体在固定化核孔蛋白上的组装产生了p10和Ran-GDP的协同结合。向这种五聚体复合物中添加GTP会导致核转运蛋白（χ）解离，推测可能是通过Ran-GDP原位形成Ran-GTP实现的。因此，p10似乎协调了核输入过程中依赖Ran的结合和解离反应。
