A KARYOPHILIC PROTEIN FORMS A STABLE COMPLEX WITH CYTOPLASMIC COMPONENTS PRIOR TO NUCLEAR-PORE BINDING
A KARYOPHILIC PROTEIN FORMS A STABLE COMPLEX WITH CYTOPLASMIC COMPONENTS PRIOR TO NUCLEAR-PORE BINDING
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DOI：
10.1074/jbc.270.15.8559
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发表时间：
1995-04-14
影响因子：
4.8
通讯作者：
YONEDA, Y
中科院分区：
文献类型：
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作者：
IMAMOTO, N;TACHIBANA, T;YONEDA, Y
亲核蛋白靶向核孔需要几种细胞质因子，包括核定位信号结合蛋白。利用洋地黄素通透性的无细胞转运实验，我们获得了含有与亲核蛋白特异结合的因子的细胞质组分，并支持转运的核结合步骤。该组分中的组分通过与核定位信号相互作用，与亲核分子形成稳定的络合物。由于这种复合体在没有其他胞液因子的情况下，在进入细胞核之前就表现出核孔结合活性，我们称之为核孔靶向复合体。它由亲核蛋白和54、56、66和90 kDa的四种蛋白组成。在我们的重建实验中，一个由54和90 kDa蛋白质组成的复合体能够将亲核细胞靶向核孔。
Targeting of karyophilic proteins to nuclear pores is known to require several cytoplasmic factors, including the nuclear location signal-binding protein. Using a digitonin-permeabilized cell-free transport assay, we have obtained a cytoplasmic fraction containing factors that specifically bind to karyophilic protein and support the nuclear binding step of the transport. Components in this fraction form a stable complex with the karyophile through interaction with nuclear location signal. Since this complex shows nuclear pore binding activity prior to nuclear entry in the absence of other cytosolic factors, we call it nuclear pore-targeting complex. It consists of karyophilic protein and four proteins of 54, 56, 66, and 90 kDa. In our reconstitution experiments, a complex with 54 and 90 kDa proteins is capable of targeting karyophiles to the nuclear pores.