Prasad Megana K, Reed Xylena, Gorkin David U, Cronin Julia C, McAdow Anthony R, Chain Kristopher, Hodonsky Chani J, Jones Erin A, Svaren John, Antonellis Anthony, Johnson Stephen L, Loftus Stacie K, Pavan William J, McCallion Andrew S
McKusick-Nathans Institute of Genetic Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
BMC Dev Biol. 2011 Jun 14;11:40. doi: 10.1186/1471-213X-11-40.
The ERBB3 gene is essential for the proper development of the neural crest (NC) and its derivative populations such as Schwann cells. As with all cell fate decisions, transcriptional regulatory control plays a significant role in the progressive restriction and specification of NC derived lineages during development. However, little is known about the sequences mediating transcriptional regulation of ERBB3 or the factors that bind them.
In this study we identified three transcriptional enhancers at the ERBB3 locus and evaluated their regulatory potential in vitro in NC-derived cell types and in vivo in transgenic zebrafish. One enhancer, termed ERBB3_MCS6, which lies within the first intron of ERBB3, directs the highest reporter expression in vitro and also demonstrates epigenetic marks consistent with enhancer activity. We identify a consensus SOX10 binding site within ERBB3_MCS6 and demonstrate, in vitro, its necessity and sufficiency for the activity of this enhancer. Additionally, we demonstrate that transcription from the endogenous Erbb3 locus is dependent on Sox10. Further we demonstrate in vitro that Sox10 physically interacts with that ERBB3_MCS6. Consistent with its in vitro activity, we also show that ERBB3_MCS6 drives reporter expression in NC cells and a subset of its derivative lineages in vivo in zebrafish in a manner consistent with erbb3b expression. We also demonstrate, using morpholino analysis, that Sox10 is necessary for ERBB3_MCS6 expression in vivo in zebrafish.
Taken collectively, our data suggest that ERBB3 may be directly regulated by SOX10, and that this control may in part be facilitated by ERBB3_MCS6.
ERBB3基因对于神经嵴（NC）及其衍生细胞群体（如施万细胞）的正常发育至关重要。与所有细胞命运决定一样，转录调控在发育过程中对NC衍生谱系的逐步限制和特化起着重要作用。然而，关于介导ERBB3转录调控的序列或与之结合的因子知之甚少。
在本研究中，我们在ERBB3基因座鉴定出三个转录增强子，并在体外NC衍生细胞类型中以及在体内转基因斑马鱼中评估了它们的调控潜力。其中一个增强子称为ERBB3_MCS6，位于ERBB3的第一个内含子内，在体外指导最高的报告基因表达，并且还表现出与增强子活性一致的表观遗传标记。我们在ERBB3_MCS6内鉴定出一个共有SOX10结合位点，并在体外证明了其对于该增强子活性的必要性和充分性。此外，我们证明内源性Erbb3基因座的转录依赖于Sox10。进一步地，我们在体外证明Sox10与ERBB3_MCS6发生物理相互作用。与其体外活性一致，我们还表明ERBB3_MCS6以与erbb3b表达一致的方式在体内驱动斑马鱼NC细胞及其部分衍生谱系中的报告基因表达。我们还使用吗啉代分析证明，Sox10对于斑马鱼体内ERBB3_MCS6的表达是必需的。
总体而言，我们的数据表明ERBB3可能受SOX10直接调控，并且这种调控可能部分由ERBB3_MCS6促成。
