A Novel Role for the AAA ATPase Spastin as a HOXA10 Transcriptional Corepressor in Ishikawa Endometrial Cells
A Novel Role for the AAA ATPase Spastin as a HOXA10 Transcriptional Corepressor in Ishikawa Endometrial Cells
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DOI：
10.1210/me.2011-0001
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发表时间：
2011-09-01
影响因子：
--
通讯作者：
Taylor, Hugh S.
中科院分区：
文献类型：
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作者：
Daftary, Gaurang S.;Tetrault, Amy M.;Taylor, Hugh S.
同源异型框A10（HOXA 10）是子宫发育和胚胎容受性所必需的转录因子，在子宫内膜中的功能位于雌激素和孕激素的下游。HOXA 10抑制空气门同源框2（EMX 2）的子宫内膜表达，EMX 2是果蝇空气门的人类直系同源物。与各种细胞活动相关的ATP酶（AAA）ATP酶痉挛素在神经递质运输中具有良好的特征作用。在这项研究中，我们描述了一个新的作用痉挛在转录调控。我们通过免疫沉淀和质谱法鉴定了Spastin作为石川核提取物中HOXA 10转录复合物的新组分。使用EMX 2作为子宫内膜HOXA 10靶基因的模型，我们发现HOXA 10-spastin辅阻遏物复合物在染色质免疫沉淀试验中结合EMX 2启动子。HOXA 10以前已经显示抑制子宫内膜EMX 2表达。我们进一步观察到，虽然HOXA 10和spastin的共转染继续抑制子宫内膜EMX 2-荧光素酶的表达，当spastin小干扰RNA与HOXA 10共转染时，抑制被逆转。Spastin核定位信号序列的突变不仅废除了其核转位，而且还废除了其与HOXA 10的共定位以及逆转EMX 2-荧光素酶抑制。在这里，我们描述了一个新的作用AAA ATP酶痉挛在石川细胞作为HOXA 10辅抑制剂EMX 2。子宫EMX 2水平与胚胎着床率呈负相关。HOXA 10作用于孕酮的下游，并已显示通过调节子宫内膜EMX 2表达促进胚胎着床。因此，子宫内膜痉挛蛋白可能作为HOXA 10的辅因子在着床生物学中具有雌激素和孕激素下游的新功能。（分子内分泌学25：1539-1549，2011）
Homeobox A10 (HOXA10), a transcription factor required for uterine development and embryo receptivity, functions downstream of estrogen and progesterone in uterine endometrium. HOXA10 represses endometrial expression of empty spiracles homeobox 2 (EMX2), the human ortholog of Drosophila empty spiracles. The ATPases associated with various cellular activities (AAA) ATPase spastin has a well-characterized role in neurotransmitter trafficking. In this study, we characterize a novel role of spastin in transcriptional regulation. We identified spastin as a novel component of the HOXA10 transcriptional complex in Ishikawa nuclear extracts by immunoprecipitation and mass spectrophotometry. Using EMX2 as a model endometrial HOXA10 target gene, we show that the HOXA10-spastin corepressor complex bound the EMX2 promoter in chromatin immunoprecipitation assays. HOXA10 has been previously shown to repress endometrial EMX2 expression. We further observed that, although cotransfection of HOXA10 and spastin continued to repress endometrial EMX2-luciferase expression, the repression was reversed when spastin small interfering RNA was cotransfected with HOXA10. Mutations in the nuclear localization signal sequences of spastin abrogated not only its nuclear translocation but also its colocalization with HOXA10 as well as reversed EMX2-luciferase repression. Here, we describe a novel role for the AAA ATPase spastin in Ishikawa cells as a HOXA10 corepressor of EMX2. Uterine EMX2 levels are inversely related to embryo implantation rates. HOXA10 acts downstream of progesterone and has been shown to facilitate embryo implantation through regulation of endometrial EMX2 expression. Endometrial spastin, therefore, likely has a novel function downstream of estrogen and progesterone in implantation biology as a cofactor of HOXA10. (Molecular Endocrinology 25: 1539-1549, 2011)