Genome-wide analysis of N1ICD/RBPJ targets in vivo reveals direct transcriptional regulation of Wnt, SHH, and hippo pathway effectors by Notch1.
The Notch pathway plays a pivotal role in regulating cell fate decisions in many stem cell systems. However, the full repertoire of Notch target genes in vivo and the mechanisms through which this pathway activity is integrated with other signaling pathways are largely unknown. Here, we report a transgenic mouse in which the activation of the Notch pathway massively expands the neural stem cell (NSC) pool in a cell context-dependent manner. Using this in vivo system, we identify direct targets of RBPJ/N1ICD in cortical NSCs at a genome-wide level through combined ChIP-Seq and transcriptome analyses. Through a highly conservative analysis of these datasets, we identified 98 genes that are directly regulated by N1ICD/RPBJ in vivo. These include many transcription factors that are known to be critical for NSC self-renewal (Sox2, Pax6, Tlx, and Id4) and the transcriptional effectors of the Wnt, SHH, and Hippo pathways, TCF4, Gli2, Gli3, Yap1, and Tead2. Since little is known about the function of the Hippo-Yap pathway in NSCs, we analyzed Yap1 expression and function in NSCs. We show that Yap1 expression is restricted to the stem cell compartment in the developing forebrain and that its expression is sufficient to rescue Notch pathway inhibition in NSC self-renewal assays. Together, results of this study reveal a previously underappreciated complexity and breadth of Notch1 targets in vivo and show direct interaction between Notch and Hippo-Yap pathways in NSCs.
The Jackson Laboratory, Bar Harbor, Maine, USA.
Yaochen
Y
Li
Matthew Aaron
MA
Hibbs
Ashley Lauren
AL
Gard
Natalia Aliakseeuna
NA
Shylo
Kyuson
K
Yun
D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D000818:Animals; D018797:Cell Cycle Proteins; D002455:Cell Division; D049109:Cell Proliferation; D047369:Chromatin Immunoprecipitation; D005786:Gene Expression Regulation; D016678:Genome / Q000235:genetics*; D053823:Hedgehog Proteins / Q000235:genetics* / Q000378:metabolism; D051819:Immunoglobulin J Recombination Signal Sequence-Binding Protein / Q000378:metabolism*; D051379:Mice; D058953:Neural Stem Cells; D010641:Phenotype; D010750:Phosphoproteins / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D051881:Receptor, Notch1 / Q000737:chemistry / Q000378:metabolism*; D015398:Signal Transduction; D013234:Stem Cells / Q000166:cytology; D014158:Transcription, Genetic; D059467:Transcriptome / Q000235:genetics; D051153:Wnt Proteins / Q000235:genetics* / Q000378:metabolism; D000091102:YAP-Signaling Proteins
D048868:Adaptor Proteins, Signal Transducing; D018797:Cell Cycle Proteins; D053823:Hedgehog Proteins; D051819:Immunoglobulin J Recombination Signal Sequence-Binding Protein; D010750:Phosphoproteins; C497571:Rbpj protein, mouse; D051881:Receptor, Notch1; C465570:Shh protein, mouse; D051153:Wnt Proteins; D000091102:YAP-Signaling Proteins; C486223:Yap1 protein, mouse; D017346:Protein Serine-Threonine Kinases