Nrl and Sp nuclear proteins mediate transcription of rod-specific cGMP-phosphodiesterase β-subunit gene -: Involvement of multiple response elements
Nrl and Sp nuclear proteins mediate transcription of rod-specific cGMP-phosphodiesterase β-subunit gene -: Involvement of multiple response elements
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DOI：
10.1074/jbc.m103301200
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发表时间：
2001-09-14
影响因子：
4.8
通讯作者：
Farber, DB
中科院分区：
文献类型：
--
作者：
Lerner, LE;Gribanova, YE;Farber, DB
cGMP-磷酸二酯酶（PDE）是视杆细胞信号转导的关键效应子。编码其催化β亚基（β-PDE）的基因突变会导致视网膜变性，从而导致失明.我们报道，该基因上游区域的短-93至+53序列足以在离体保存的Y 79人视网膜母细胞瘤细胞和爪蟾胚胎头部中进行β-PDE转录。该序列在转基因非洲爪蟾蝌蚪中也起着最小的杆状特异性启动子的作用。Nrl转录因子在体外与位于该区域内的β Ap 1/NRE调节元件结合，并且当在非视网膜293胚胎肾细胞中过表达时将其反式激活。我们还发现了一个G/C丰富的激活元件，β/GC，在Y 79视网膜母细胞瘤细胞和非洲爪蟾胚胎的启动子活性的重要。普遍存在的Sp1和中枢神经系统特异性Sp 4转录因子都在视网膜中表达，并在体外与该元件相互作用。β/GC-Y 79核蛋白复合物的电泳迁移率被针对Sp1和Sp 4的抗体改变。因此，我们的研究结果牵连Nr 1，Sp1，和Sp 4在杆特异性最小β-PDE启动子的转录调控。我们还得出结论，非洲爪蟾是一个有效的系统，用于分析人类β-PDE启动子，并可用于研究其他人类视网膜基因离体和体内。
cGMP-phosphodiesterase (PDE) is the key effector in rod photoreceptor signal transduction. Mutations in the gene encoding its catalytic, beta -subunit (beta -PDE) cause retinal degenerations leading to blindness. We report that the short -93 to +53 sequence in the upstream region of this gene is sufficient for beta -PDE transcription in both Y79 human retinoblastoma cells and Xenopus embryo heads maintained ex vivo. This sequence also functions as a minimal rod-specific promoter in transgenic Xenopus tadpoles. The Nrl transcription factor binds in vitro to the beta Ap1/NRE regulatory element located within this region and transactivates it when overexpressed in non-retinal 293 embryonic kidney cells. We also found a G/C-rich activator element, beta /GC, important for promoter activity in Y79 retinoblastoma cells and Xenopus embryos. Both the ubiquitous Sp1 and the central nervous system-specific Sp4 transcription factors are expressed in retina and interact with this element in vitro. Electrophoretic mobilities of beta /GC-Y79 nuclear protein complexes are altered by antibodies against Sp1 and Sp4. Thus, our results implicate Nr1, Sp1, and Sp4 in transcriptional regulation of the rod-specific minimal beta -PDE promoter. We also conclude that Xenopus laevis is an efficient system for analyzing the human beta -PDE promoter and may be used to study other human retinal genes ex vivo and in vivo.