Boppana Sridhar, Scheglov Alexander, Geffers Robert, Tarabykin Victor
Max-Planck-Institute for Experimental Medicine, Hermann-Rein Strasse 3, 37075 Göttingen, Germany.
Biochim Biophys Acta. 2012 Feb;1820(2):151-6. doi: 10.1016/j.bbagen.2011.09.015. Epub 2011 Oct 4.
Transcription factor Pax6 plays an essential role in the expression of other transcription factors, cell adhesion molecules and is crucial for neurogenesis in the developing forebrain. Analysis of gene expression profiles through microarray experiments in Pax6 mutants allowed us to focus on CRALBP, one of the many genes that were downregulated.
We studied the expression of CRALBP in wt and Pax6-/- mutants through in situ hybridization and immunohistochemistry. ChIP assay and luciferase reporter assay were performed to show the regulatory role of Pax6 on CRALBP promoter.
RNA and protein expression data show that CRALBP expression was completely abolished in Pax6 mutants. In vivo binding assays and in vitro reporter assays indicate that Pax6 not only binds the promoter of CRALBP but also positively regulates protein expression.
This work provides evidence supporting that CRALBP is a direct downstream target of Pax6. However, the role of CRALBP in the cortex is yet to be elucidated.
Pax6 is a marker expressed on neural stem cells and progenitor cells. Understanding Pax6-dependent gene regulatory mechanisms unravels signaling cascades that occur early during development.
转录因子Pax6在其他转录因子、细胞黏附分子的表达中起重要作用，对发育中的前脑神经发生至关重要。通过对Pax6突变体进行微阵列实验分析基因表达谱，使我们能够聚焦于众多下调基因之一的CRALBP。
我们通过原位杂交和免疫组织化学研究了野生型和Pax6基因敲除突变体中CRALBP的表达。进行了染色质免疫沉淀分析和荧光素酶报告基因分析，以显示Pax6对CRALBP启动子的调控作用。
RNA和蛋白质表达数据表明，CRALBP表达在Pax6突变体中完全消失。体内结合分析和体外报告基因分析表明，Pax6不仅结合CRALBP的启动子，还正向调节蛋白质表达。
这项工作提供了证据支持CRALBP是Pax6的直接下游靶点。然而，CRALBP在皮质中的作用尚待阐明。
Pax6是在神经干细胞和祖细胞上表达的标志物。了解Pax6依赖的基因调控机制有助于揭示发育早期发生的信号级联反应。
