Identification and analysis of nucleocytoplasmic transport pathway using our novel assay system

以往的研究表明，由Importin β家族成员介导的常规核质转运在细胞应激条件下下调，而分子伴侣Hsc 70/Hsp 70在热休克反应中迅速积聚到细胞核中。然而，这种转移到细胞核中的机制仍然难以捉摸。在这项研究中，我们纯化的细胞溶质蛋白，是必不可少的核进口的Hsc 70/Hsp 70。我们的数据表明，该分子是一种新的核输入受体Hsc 70/Hsp 70。

Previous studies suggest that the conventional nucleocytoplasmic transport, which is mediated by members of Importin β family, is down-regulated under cellular stress conditions, whereas molecular chaperones Hsc70/Hsp70 is well known to accumulate rapidly into the nucleus in response to heat shock. However, this mechanisms translocating into the nucleus remain elusive. In this study, we purified biochemically a cytosolic protein that is essential for nuclear import of Hsc70/Hsp70. Our data suggest that this molecule is a novel nuclear import receptor for Hsc70/Hsp70.