Understanding Mechanisms of GLI-Mediated Transcription during Craniofacial Development and Disease Using the Ciliopathic Mutant, talpid(2).
Understanding Mechanisms of GLI-Mediated Transcription during Craniofacial Development and Disease Using the Ciliopathic Mutant, talpid(2).
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DOI：
10.3389/fphys.2016.00468
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发表时间：
2016
影响因子：
4
通讯作者：
Brugmann SA
中科院分区：
文献类型：
--
作者：
Chang YT;Chaturvedi P;Schock EN;Brugmann SA
初级纤毛是一种普遍存在的、基于微管的细胞器，细胞利用它来转导分子信号。纤毛病是一组由初级纤毛的结构或功能破坏引起的疾病。超过 30% 的纤毛病主要由颅面部表型定义，通常包括中面部缺陷、唇裂/腭裂、小颌畸形、失语和颅缝早闭。纤毛病中颅面表型的频率和严重程度强调了纤毛在颅面复合体发育过程中的重要性。从分子角度来看，许多纤毛病突变体，包括禽类 talpid2 (ta2)，报告病理学上高水平的全长 GLI3 (GLI3FL)，它可以继续发挥激活剂 (GLIA) 的作用，并且截短的 GLI3 (GLI3T) 的产生减少，它可以继续发挥阻抑剂 (GLIR) 的作用。这些观察结果表明，像 ta2 这样的纤毛突变体的颅面表型是由 GLIA 活性过度或 GLIR 活性降低引起的。为了解释这两种情况，我们检查了 GLI3 在靶基因调控区域的占据情况以及随后的靶基因表达。使用计算机策略，我们确定了鸟类基因组中共有的 GLI 结合区 (GBR)，并通过染色质免疫沉淀 (ChIP) 证实了 GLI3 与其靶标的调节区结合。在 ta2 突变体中，与对照胚胎相比，面部突出表达显着增加的 GLI3 靶基因数量惊人地少，并且与靶基因相关的 GLI3 占用率大大降低。体外 DNA 结合测定进一步支持了 ChIP 结果，表明 ta2 突变体中产生的过量 GLI3FL 不会与 GBR 结合。根据这些结果，我们探讨了 GLI 辅助调节蛋白在 GLI 介导的转录调节机制中发挥作用的可能性。综上所述，我们的研究表明，颅面纤毛病表型是通过减少 GLIT 产生而产生的，从而允许靶基因转录由 GLI 共调节因子的组合密码介导。
The primary cilium is a ubiquitous, microtubule-based organelle that cells utilize to transduce molecular signals. Ciliopathies are a group of diseases that are caused by a disruption in the structure or function of the primary cilium. Over 30% of all ciliopathies are primarily defined by their craniofacial phenotypes, which typically include midfacial defects, cleft lip/palate, micrognathia, aglossia, and craniosynostosis. The frequency and severity of craniofacial phenotypes in ciliopathies emphasizes the importance of the cilium during development of the craniofacial complex. Molecularly, many ciliopathic mutants, including the avian talpid2 (ta2), report pathologically high levels of full-length GLI3 (GLI3FL), which can go on to function as an activator (GLIA), and reduced production of truncated GLI3 (GLI3T), which can go on to function as a repressor (GLIR). These observations suggest that the craniofacial phenotypes of ciliary mutants like ta2 are caused either by excessive activity of the GLIA or reduced activity of GLIR. To decipher between these two scenarios, we examined GLI3 occupation at the regulatory regions of target genes and subsequent target gene expression. Using in silico strategies we identified consensus GLI binding regions (GBRs) in the avian genome and confirmed GLI3 binding to the regulatory regions of its targets by chromatin immunoprecipitation (ChIP). In ta2 mutants, there was a strikingly low number of GLI3 target genes that had significantly increased expression in facial prominences compared to the control embryo and GLI3 occupancy at GBRs associated with target genes was largely reduced. In vitro DNA binding assays, further supported ChIP results, indicated that the excessive GLI3FL generated in ta2 mutants did not bind to GBRs. In light of these results, we explored the possibility of GLI co-regulator proteins playing a role in regulatory mechanism of GLI-mediated transcription. Taken together our studies suggest that craniofacial ciliopathic phenotypes are produced via reduced GLIT production, allowing for target gene transcription to be mediated by the combinatorial code of GLI co-regulators.
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影响因子：
7.3
作者：
Falkenstein, Kristin N.;Vokes, Steven A.
通讯作者：
Vokes, Steven A.
DOI：
10.1242/dev.029835
发表时间：
2008-12
期刊：
Development (Cambridge, England)
影响因子：
--
作者：
Hoover AN;Wynkoop A;Zeng H;Jia J;Niswander LA;Liu A
通讯作者：
Liu A
影响因子：
3.5
作者：
Brugmann, Samantha A.;Allen, Nancy C.;Helms, Jill A.
通讯作者：
Helms, Jill A.
影响因子：
2.9
作者：
Barnfield, PC;Zhang, XY;Hui, CC
通讯作者：
Hui, CC
影响因子：
1.7
作者：
Darnell, D. K.;Kaur, S.;Antin, P. B.
通讯作者：
Antin, P. B.