Chromatin relaxation in response to DNA doublestrand breaks is modulated by a novel ATM- and KAP-1 dependent pathway
Chromatin relaxation in response to DNA doublestrand breaks is modulated by a novel ATM- and KAP-1 dependent pathway. NIHMS1508500-supplement-6.xlsx (60K) GUID:?E4F01B7C-495C-4880-A361-8E14FF0B4803 7: RNA-seq results and analyses CNN RNA-seq comparing E12.5 control and Lats1/2;Nestin-Cre dKO telencephalons. Differentially expressed genes called by ERCC normalization and read-depth normalization are listed for comparison. NIHMS1508500-supplement-7.xlsx (4.4M) GUID:?3C30FC34-9FFB-4F1B-B589-651803AD28BD 8: NanoString NanoString nCounter analysis comparing RNAs extracted from equal numbers of E12.5 control and Lats1/2;Nestin-Cre dKO telencephalic cells. Raw counts and normalized (to housekeeping genes) counts are shown. NIHMS1508500-supplement-8.xlsx (321K) GUID:?862DBEC8-7D6D-4825-AB7E-DCABDC029C86 SUMMARY The Hippo pathway controls the activity of YAP/TAZ transcriptional coactivators through a kinase cascade. Despite the critical role of this pathway in tissue growth and tumorigenesis, it remains unclear how YAP/TAZCmediated transcription drives proliferation. By analyzing the effects of inactivating LATS1/2 kinases, the direct upstream inhibitors of YAP/TAZ, on mouse brain development and applying cell-numberCnormalized transcriptome analyses, we discovered that YAP/TAZ activation causes a global increase in transcription activity, known as hypertranscription, and upregulates many genes associated with cell growth and proliferation. In contrast, conventional Tetrahydropapaverine HCl read-depthCnormalized RNA-sequencing analysis failed to detect the scope of the transcriptome shift and missed most relevant gene ontologies. Following a transient increase in proliferation, however, hypertranscription in neural progenitors triggers replication stress, DNA damage, and p53 activation, resulting in massive apoptosis. Our findings reveal a significant impact of YAP/TAZ activation on global transcription activity and have important implications for understanding YAP/TAZ function. In Brief Using cell-numberCnormalized transcriptome analysis, Lavado et al. show that inactivation of Hippo pathway LATS1/2 kinases during brain development causes YAP/TAZCdriven global hypertranscription, upregulating many genes involved in cell growth and proliferation. Hypertranscription in neural progenitors inhibits differentiation and triggers replication stress and DNA damage, resulting in massive apoptosis. GRAPHIC ABSTRACT INTRODUCTION The Hippo pathway regulates the development, homeostasis, regeneration, and tumorigenesis of various tissues across species (Pfleger, 2017; Yu et al., 2015). At its Tetrahydropapaverine HCl core are a kinase cascade and a transcription factor complex (Meng et al., 2016). The upstream kinases MST1 and MST2 activate the downstream kinases LATS1 and LATS2 (LATS1/2), which in turn phosphorylate the homologous transcriptional coactivators YAP and TAZ (YAP/TAZ)the key effectors of the Hippo pathwayresulting in their cytoplasmic sequestration or degradation. When the Hippo kinase cascade is inactivated, unphosphorylated YAP/TAZ enter the nucleus, where they interact with the TEAD family of DNA-binding factors and activate gene expression. The most prominent function of YAP/TAZ is to promote cell proliferation and survival. Accordingly, animal models of Hippo pathway inactivation or YAP/TAZ activation almost always exhibit overgrowth or tumorigenic phenotypes, and YAP/TAZ activation has been observed in nearly all types Rabbit Polyclonal to CA14 of human solid tumor and is associated with tumor aggression and poor outcomes (Zanconato et al., 2016). Despite this, the genes that are consistently and strongly induced by YAP/TAZ in different contexts are often those related to the extracellular matrix (ECM), cell adhesion, and epithelial-to-mesenchymal transition (EMT) and are rarely those related to proliferation (Cai et al., 2015; Lavado et al., 2013; Lee et al., 2016; Ota and Sasaki, 2008; Su et al., 2015), raising the question of how YAP/TAZ activation drives proliferation in Tetrahydropapaverine HCl so many contexts. As LATS1/2 directly phosphorylate YAP/TAZ, they are probably the most important gatekeepers of YAP/TAZ activation in many contexts. Indeed, mice lacking in the developing gut (Cotton et al., 2017), kidney (Reginensi et al., 2016), and liver (Lee et al., 2016); in growing blood vessels (Kim et al., 2017); and in the adult liver (Chen et al., 2015; Lee et al., 2016) and heart (Heallen et al., 2013) all show.