Two enhancers control transcription of Drosophila muscleblind in the embryonic somatic musculature and in the central nervous system.
Two enhancers control transcription of Drosophila muscleblind in the embryonic somatic musculature and in the central nervous system.
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DOI：
10.1371/journal.pone.0093125
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发表时间：
2014
期刊：
影响因子：
3.7
通讯作者：
Artero R
中科院分区：
文献类型：
--
作者：
Bargiela A;Llamusi B;Cerro-Herreros E;Artero R
系统发育保守的Muscleblind蛋白家族是参与多种基因表达过程的RNA结合因子，包括选择性剪接调节、RNA稳定性和亚细胞定位以及miRNA生物发生，通常有助于细胞类型特异性分化。在人类中，肌盲样蛋白MBNL1和MBNL2的隔离与退行性疾病有关，特别是扩张性疾病，如1型和2型肌强直性营养不良。果蝇肌肉盲症先前被证明在胚胎体细胞和内脏肌肉亚型以及中枢神经系统中表达，并依赖Mef2进行转录激活。基因组学方法已经指出了候选基因启动子和组织特异性增强子，但缺乏对其调控作用的实验证实。在我们的研究中，在S2细胞中荧光素酶报告基因检测证实P1 （515 bp）和P2 （573 bp）区域，分别涉及外显子1和外显子2的开始，能够启动RNA转录。同样，携带增强子报告结构的转基因果蝇胚胎支持两个调控区域的存在，这些区域控制着中枢神经索（NE，神经增强子；830 bp）和体细胞（骨骼）肌肉组织（ME，肌肉增强子；3.3 kb）的肌肉盲的胚胎表达。NE和ME均能促进Hsp70异源启动子的表达。在S2细胞试验中，大多数ME增强子的激活可以进一步缩小到1200 bp的亚区（ME.3），该区域包含Mef2转录因子的预测结合位点。目前的研究构成了肌盲增强子的第一个特征，并将有助于更深入地了解该基因的转录调控。
The phylogenetically conserved family of Muscleblind proteins are RNA-binding factors involved in a variety of gene expression processes including alternative splicing regulation, RNA stability and subcellular localization, and miRNA biogenesis, which typically contribute to cell-type specific differentiation. In humans, sequestration of Muscleblind-like proteins MBNL1 and MBNL2 has been implicated in degenerative disorders, particularly expansion diseases such as myotonic dystrophy type 1 and 2. Drosophila muscleblind was previously shown to be expressed in embryonic somatic and visceral muscle subtypes, and in the central nervous system, and to depend on Mef2 for transcriptional activation. Genomic approaches have pointed out candidate gene promoters and tissue-specific enhancers, but experimental confirmation of their regulatory roles was lacking. In our study, luciferase reporter assays in S2 cells confirmed that regions P1 (515 bp) and P2 (573 bp), involving the beginning of exon 1 and exon 2, respectively, were able to initiate RNA transcription. Similarly, transgenic Drosophila embryos carrying enhancer reporter constructs supported the existence of two regulatory regions which control embryonic expression of muscleblind in the central nerve cord (NE, neural enhancer; 830 bp) and somatic (skeletal) musculature (ME, muscle enhancer; 3.3 kb). Both NE and ME were able to boost expression from the Hsp70 heterologous promoter. In S2 cell assays most of the ME enhancer activation could be further narrowed down to a 1200 bp subregion (ME.3), which contains predicted binding sites for the Mef2 transcription factor. The present study constitutes the first characterization of muscleblind enhancers and will contribute to a deeper understanding of the transcriptional regulation of the gene.
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影响因子：
4.5
作者：
Cunha PM;Sandmann T;Gustafson EH;Ciglar L;Eichenlaub MP;Furlong EE
通讯作者：
Furlong EE
影响因子：
2.7
作者：
Artero, R;Prokop, A;Baylies, MK
通讯作者：
Baylies, MK
影响因子：
3.5
作者：
JAGLA, K;GEORGEL, P;BELLARD, M
通讯作者：
BELLARD, M
影响因子：
1.2
作者：
Kanadia, RN;Urbinati, CR;Swanson, MS
通讯作者：
Swanson, MS
影响因子：
2.7
作者：
De Graeve, F;Jagla, T;Jagla, K
通讯作者：
Jagla, K