Expression analyses and transcriptional regulation of mouse nucleolar spindle-associated protein gene in erythroid cells: essential role of NF-Y
Expression analyses and transcriptional regulation of mouse nucleolar spindle-associated protein gene in erythroid cells: essential role of NF-Y
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DOI：
10.1111/j.1365-2141.2006.06340.x
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发表时间：
2006-11-01
影响因子：
6.5
通讯作者：
Sasaki, Takeshi
中科院分区：
文献类型：
--
作者：
Fujiwara, Tohru;Harigae, Hideo;Sasaki, Takeshi
核仁纺锤体相关蛋白（NuSAP）是一种最近鉴定的微管相关蛋白，似乎参与细胞周期调节。已经证明NuSAP优先在造血细胞的红系中表达。为了证实其在红细胞生成中的作用，我们检测了NuSAP基因的表达谱。在分级分离的小鼠成红细胞中，NuSAP mRNA在对应于未成熟成红细胞的亚群（TER 119（+）CD 71（高））中比成熟成红细胞（TER 119（+）CD 71（低））显著更丰富，并且与对照小鼠相比，其在来自体内放血小鼠的TER 119（+）细胞中显著增加。此外，在二甲基亚砜诱导的小鼠红白血病（MEL）细胞红系成熟过程中，NuSAP mRNA在24-72 h增加。这些结果表明，NuSAP基因可能有助于未成熟成红细胞池的扩增。利用MEL细胞研究NuSAP基因的调控机制。序列分析表明，NuSAP启动子含有4个CCAAT盒、一个Sp1元件、一个GATA样元件、一个CACCC元件和一个Myb元件，缺少一个TATA盒。启动子分析表明，位于-81/-85和-30/-34的重复CCAAT盒是启动子活性所必需的。此外，启动子通过这些元件被NF-YA反式激活。提示NuSAP可能在NF-γ调控的红系细胞增殖中起重要作用。
Nucleolar spindle-associated protein (NuSAP), a recently characterised microtubule-associated protein, appears to participate in cell cycle regulation. It has been demonstrated that NuSAP is expressed preferentially in the erythroid lineage in haematopoietic cells. To characterise its role in erythropoiesis, we examined the expression profile of the NuSAP gene. In fractionated murine erythroblasts, NuSAP mRNA was remarkably more abundant in the subset corresponding to immature erythroblasts (TER119(+)CD71(high)) than mature erythroblasts (TER119(+)CD71(low)), and it was significantly increased in TER119(+) cells from in vivo phlebotomised mice compared with control mice. Furthermore, during erythroid maturation of mouse erythroleukaemia (MEL) cells by dimethylsulfoxide, NuSAP mRNA was increased at 24-72 h. These results suggested that the NuSAP gene might contribute to the expansion of immature erythroblast pool. The regulatory mechanism of NuSAP gene was investigated using MEL cells. Sequence analysis revealed that NuSAP promoter has four CCAAT boxes, an Sp1 element, a GATA-like element, a CACCC element, a Myb element and lacks a TATA box. Promoter analyses demonstrated that duplicated CCAAT boxes located at -81/-85 and -30/-34 were essential for promoter activity. Furthermore, the promoter was trans-activated by NF-YA through these elements. These results suggest that NuSAP might play an important role in erythroid proliferation under the control of NF-Y.