The myeloid leukemia factor interacts with COP9 signalosome subunit 3 in Drosophila melanogaster
The myeloid leukemia factor interacts with COP9 signalosome subunit 3 in Drosophila melanogaster
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DOI：
10.1111/j.1742-4658.2007.06229.x
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发表时间：
2008-02
期刊：
影响因子：
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通讯作者：
Wakana Sugano;K. Ohno;N. Yoneda‐Kato;J. Kato;M. Yamaguchi
中科院分区：
文献类型：
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作者：
Wakana Sugano;K. Ohno;N. Yoneda‐Kato;J. Kato;M. Yamaguchi
人髓性白血病因子1（human myeloid leukemia factor 1，hMLF 1）基因是由染色体易位产生的NPM-hMLF 1融合基因。在果蝇中，dMLF已被鉴定为与hMLF 1和hMLF 2同源的蛋白质，其与参与转录调控的各种因子相互作用。然而，dMLF的精确细胞功能仍不清楚。为了产生进一步的见解，我们首先使用dMLF特异性抗体检查了dMLF蛋白的行为。免疫组化分析表明，dMLF定位于细胞核中的早期胚胎和培养细胞。使用无眼GAL 4驱动器在发育中的眼胚盘中异位表达dMLF导致小眼表型，细胞周期蛋白E的共表达挽救了小眼表型，表明dMLF参与细胞周期调控。因此，我们分析了dMLF和dMLF相互作用蛋白dCSN 3之间相互作用的分子机制，dCSN 3是COP 9信号体的一个亚基，它调节多种信号传导和细胞周期途径。生化和遗传分析显示，dMLF与dCSN 3在体内相互作用，谷胱甘肽S-转移酶下拉试验显示，dCSN 3蛋白的PCI结构域足以发生这种相互作用，可能充当COP 9信号体复合物组装的结构支架。从这些数据中，我们提出了dMLF在COP 9信号体复合物的组装中起负面作用的可能性。
The human myeloid leukemia factor 1 (hMLF1) gene was first identified as an NPM–hMLF1 fusion gene produced by chromosomal translocation. In Drosophila, dMLF has been identified as a protein homologous to hMLF1 and hMLF2, which interacts with various factors involved in transcriptional regulation. However, the precise cellular function of dMLF remains unclear. To generate further insights, we first examined the behavior of dMLF protein using an antibody specific to dMLF. Immunostaining analyses showed that dMLF localizes in the nucleus in early embryos and cultured cells. Ectopic expression of dMLF in the developing eye imaginal disc using eyeless‐GAL4 driver resulted in a small‐eye phenotype and co‐expression of cyclin E rescued the small‐eye phenotype, suggesting the involvement of dMLF in cell‐cycle regulation. We therefore analyzed the molecular mechanism of interactions between dMLF and a dMLF‐interacting protein, dCSN3, a subunit of the COP9 signalosome, which regulates multiple signaling and cell‐cycle pathways. Biochemical and genetic analyses revealed that dMLF interacts with dCSN3 in vivo and glutathione S‐transferase pull‐down assays revealed that the PCI domain of the dCSN3 protein is sufficient for this to occur, possibly functioning as a structural scaffold for assembly of the COP9 signalosome complex. From these data we propose the possibility that dMLF plays a negative role in assembly of the COP9 signalosome complex.