A mechanism of nucleocytoplasmic trafficking for the homeodomain protein PRH.
A mechanism of nucleocytoplasmic trafficking for the homeodomain protein PRH.
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DOI：
10.1007/s11010-009-0188-0
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发表时间：
2009-12
影响因子：
4.3
通讯作者：
Radu, Aurelian
中科院分区：
文献类型：
--
作者：
Ploski, Jonathan E.;Topisirovic, Ivan;Park, Kevin W.;Borden, Katherine L. B.;Radu, Aurelian
PRH/Hex是一种同源结构域蛋白，在早期胚胎构型和造血过程中发挥重要作用。PRH既可以作为肿瘤抑制因子，也可以作为癌基因，其表达在某些类型的淋巴系和髓系白血病中表达失调。PRH从细胞核中异常排除与甲状腺癌、乳腺癌和部分髓系白血病有关。因此，发现PRH的核定位对于抑制eIF4E依赖的转化是必要的。由于PRH的核浆定位与肿瘤转化有关，我们试图更好地了解PRH是如何运输到核室的。在这里，我们报道了控制PRH核质转运机制的一个基本元件，即它是通过Karyopherin/Importin 7进入细胞核的。Kap7在HeLa细胞蛋白裂解物的GST下拉中被鉴定为PRH的结合伙伴，随后进行了质谱分析。Kap7-PrH复合体在RanGTP存在下解离，正如核进口复合体所预期的那样。在GST-down实验中，KAP7可以直接与PRH结合，在洋地黄素通透性细胞实验中，KAP7还可以介导PRH向核间室的转运。最后，Kap7在体内的耗尽显著减少了PRH在细胞核中的积累。我们的数据为研究扰动的PRH在肿瘤中定位的机制和可能的治疗干预开辟了道路。
PRH/Hex is a homeodomain protein that plays an important role in early embryonic patterning and hematopoiesis. PRH can act as either a tumor suppressor or an oncogene and its expression is dysregulated in certain types of lymphoid and myeloid leukemias. Aberrant exclusion of PRH from the nuclei has been associated with thyroid and breast cancers and a subset of myeloid leukemias. Accordingly, nuclear localization of PRH was found to be necessary for the inhibition of eIF4E dependent transformation. Since PRH’s nuclear-cytoplasmic localization has been associated with neoplastic transformation we sought to better understand how PRH is transported to the nuclear compartment. Here we report an essential element that controls the mechanism of PRH nucleocytoplasmic trafficking, namely that it is imported into the nuclei by Karyopherin/Importin 7. Kap7 was identified as a binding partner for PRH in a GST pulldown from a HeLa cell protein lysate, followed by mass spectrometry. The Kap7-PRH complex is dissociated in the presence of RanGTP, as expected for a nuclear import complex. Kap7 can bind directly to PRH in a GST-pull down assay with purified proteins, as well as mediates the transport of PRH to the nuclear compartment in a digitonin permeabilized cells assay. Lastly, in vivo depletion of Kap7 dramatically reduces accumulation of PRH in the nucleus. Our data open the way for investigations of the mechanism of perturbed PRH localization in tumors and possible therapeutic interventions.
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DOI：
10.1083/jcb.138.1.65
发表时间：
1997-07-14
期刊：
The Journal of cell biology
影响因子：
--
作者：
Görlich D;Dabrowski M;Bischoff FR;Kutay U;Bork P;Hartmann E;Prehn S;Izaurralde E
通讯作者：
Izaurralde E
影响因子：
8
作者：
George, A;Morse, HC;Justice, MJ
通讯作者：
Justice, MJ
影响因子：
16
作者：
Chuderland, Dana;Konson, Alexander;Seger, Rony
通讯作者：
Seger, Rony
影响因子：
4.8
作者：
Fu, Xinrong;Choi, Yuk-Kwan;Qi, Robert Z.
通讯作者：
Qi, Robert Z.
影响因子：
11.4
作者：
BISCHOFF, FR;KREBBER, H;PONSTINGL, H
通讯作者：
PONSTINGL, H