Patched1 interacts with cyclin B1 to regulate cell cycle progression
Patched1 interacts with cyclin B1 to regulate cell cycle progression
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DOI：
10.1093/emboj/20.9.2214
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发表时间：
2001-05-01
期刊：
影响因子：
11.4
通讯作者：
Donoghue, DJ
中科院分区：
文献类型：
--
作者：
Barnes, EA;Kong, M;Donoghue, DJ
有丝分裂的开始需要m期促进因子（MPF）的激活。MPF激活及其亚细胞定位依赖于其组分cdc2和细胞周期蛋白B1的磷酸化状态。在使用诱饵蛋白模拟磷酸化的细胞周期蛋白B1的双杂交筛选中，我们发现了细胞周期蛋白B1和patched1 （ptc1）之间的一种新的相互作用，ptc1是一种与基底细胞癌（BCC）相关的肿瘤抑制因子。Ptc1特异性地与组成磷酸化的细胞周期蛋白B1衍生物相互作用，并能够改变其正常的亚细胞定位。此外，ptc1配体、音猬（shh）的加入破坏了这种相互作用，并允许细胞周期蛋白B1定位到细胞核。ptc1在293T细胞中的表达对细胞增殖有抑制作用；这种抑制可以通过细胞周期蛋白B1衍生物的共表达来缓解，该衍生物组成部分定位于细胞核，由于Ala的磷酸化位点突变而不能与ptc1相互作用。此外，我们证明内源性ptc1和内源性细胞周期蛋白B1在体内相互作用。本文报道的研究结果表明，ptc1参与决定细胞周期蛋白B1的亚细胞定位，并提示ptc1的肿瘤抑制活性与细胞分裂调节之间存在联系。因此，我们提出ptc1通过调控MPF的定位参与G(2)/M检查点。
The initiation of mitosis requires the activation of M-phase promoting factor (MPF). MPF activation and its subcellular localization are dependent on the phosphorylation state of its components, cdc2 and cyclin B1. In a two-hybrid screen using a bait protein to mimic phosphorylated cyclin B1, we identified a novel interaction between cyclin B1 and patched1 (ptc1), a tumor suppressor associated with basal cell carcinoma (BCC). Ptc1 interacted specifically with constitutively phosphorylated cyclin B1 derivatives and was able to alter their normal subcellular localization. Furthermore, addition of the ptc1 ligand, sonic hedgehog (shh), disrupts this interaction and allows cyclin B1 to localize to the nucleus. Expression of ptc1 in 293T cells was inhibitory to cell proliferation; this inhibition could be relieved by coexpression of a cyclin B1 derivative that constitutively localizes to the nucleus and that could not interact with ptc1 due to phosphorylation-site mutations to Ala. In addition, we demonstrate that endogenous ptc1 and endogenous cyclin B1 interact in vivo. The findings reported here demonstrate that ptc1 participates in determining the subcellular localization of cyclin B1 and suggest a link between the tumor suppressor activity of ptc1 and the regulation of cell division. Thus, we propose that ptc1 participates in a G(2)/M checkpoint by regulating the localization of MPF.