Nadler S G, Tritschler D, Haffar O K, Blake J, Bruce A G, Cleaveland J S
Bristol-Myers Squibb Pharmaceutical Research Institute, Seattle, Washington 98121, USA.
J Biol Chem. 1997 Feb 14;272(7):4310-5. doi: 10.1074/jbc.272.7.4310.
The process of nuclear protein transport requires the interaction of several different proteins, either directly or indirectly with nuclear localization or targeting sequences (NLS). Recently, a number of karyopherins alpha, or NLS-binding proteins, have been identified. We have found that the karyopherins hSRP1 and hSRP1alpha are differentially expressed in various leukocyte cell lines and could be induced in normal human peripheral blood lymphocytes. We show that the two karyopherins bind with varied specificities in a sequence specific manner to different NLSs and that the sequence specificity is modulated by other cytosolic proteins. There was a correlation between binding of karyopherins alpha to different NLSs and their ability to be imported into the nucleus. Taken together, these data provide evidence for multiple levels of control of the nuclear import process.
核蛋白转运过程需要几种不同蛋白质直接或间接与核定位或靶向序列（NLS）相互作用。最近，已鉴定出多种核转运蛋白α或NLS结合蛋白。我们发现核转运蛋白hSRP1和hSRP1α在各种白细胞细胞系中差异表达，并且可在正常人外周血淋巴细胞中被诱导。我们表明，这两种核转运蛋白以序列特异性方式与不同的NLS以不同的特异性结合，并且序列特异性受其他胞质蛋白调节。核转运蛋白α与不同NLS的结合与其导入细胞核的能力之间存在相关性。综上所述，这些数据为核输入过程的多层次控制提供了证据。
