Project description:YAP and TAZ are transcription cofactors implicated in the contractile and pro-fibrotic activation of fibroblasts. Fibroblast contractile function is important in alveologenesis, as well as in lung wound healing and fibrosis. As paralogs, YAP and TAZ may have independent or redundant roles in regulating transcriptional programs and contractile function. Using IMR-90 lung fibroblasts, microarray analysis and traction microscopy we tested whether independent YAP or TAZ knockdown alone was sufficient to limit transcriptional activation and contraction in vitro.
Project description:Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ) are transcription cofactors implicated in the contractile and profibrotic activation of fibroblasts. Fibroblast contractile function is important in alveologenesis and in lung wound healing and fibrosis. As paralogs, YAP and TAZ may have independent or redundant roles in regulating transcriptional programs and contractile function. Using IMR-90 lung fibroblasts, microarray analysis, and traction microscopy, we tested whether independent YAP or TAZ knockdown alone was sufficient to limit transcriptional activation and contraction in vitro. Our results demonstrate limited effects of knockdown of either YAP or TAZ alone, with more robust transcriptional and functional effects observed with combined knockdown, consistent with cooperation or redundancy of YAP and TAZ in transforming growth factor β1 (TGFβ1)-induced fibroblast activation and contractile force generation. The transcriptional responses to combined YAP/TAZ knockdown were focused on a relatively small subset of genes with prominent overrepresentation of genes implicated in contraction and migration. To explore potential disease relevance of our findings, we tested primary human lung fibroblasts isolated from patients with idiopathic pulmonary fibrosis and confirmed that YAP and TAZ combined knockdown reduced the expression of three cytoskeletal genes, ACTA2, CNN1, and TAGLN. We then compared the contribution of these genes, along with YAP and TAZ, to contractile function. Combined knockdown targeting YAP/TAZ was more effective than targeting any of the individual cytoskeletal genes in reducing contractile function. Together, our results demonstrate that YAP and TAZ combine to regulate a multigene program that is essential to fibroblast contractile function.
Project description:The optic vesicle comprises a pool of bi-potential progenitor cells from which the retinal pigment epithelium (RPE) and neural retina fates segregate during ocular morphogenesis. Several transcription factors and signaling pathways have been shown to be important for RPE maintenance and differentiation, but an understanding of the initial fate specification and determination of this ocular cell type is lacking. We show that Yap/Taz-Tead activity is necessary and sufficient for optic vesicle progenitors to adopt RPE identity in zebrafish. A Teadresponsive transgene is expressed within the domain of the optic cup from which RPE arises, and Yap immunoreactivity localizes to the nuclei of prospective RPE cells. yap (yap1) mutants lack a subset of RPE cells and/or exhibit coloboma. Loss of RPE in yap mutants is exacerbated in combination with taz (wwtr1) mutant alleles such that, when Yap and Taz are both absent, optic vesicle progenitor cells completely lose their ability to form RPE. The mechanism of Yap dependent RPE cell type determination is reliant on both nuclear localization of Yap and interaction with a Tead co-factor. In contrast to loss of Yap and Taz, overexpression of either protein within optic vesicle progenitors leads to ectopic pigmentation in a dosagedependent manner. Overall, this study identifies Yap and Taz as key early regulators of RPE genesis and provides a mechanistic framework for understanding the congenital ocular defects of Sveinsson’s chorioretinal atrophy and congenital retinal coloboma. 60 pooled eyes from 36 hpf wild type or vsx2:Gal4/dsRed:14xUAS:YapS87A embryos were pooled for one sample. Three wild type and three vsx2:Gal4/dsRed:14xUAS:YapS87A pools were analyzed for RNA.
Project description:The two effector proteins of the Hippo signaling pathway, YAP and TAZ, play a pivotal role in the cellular homeostasis of podocytes and in the pathogenesis of focal segmental glomerulosclerosis (FSGS). We aim to unravel the unique and redundant functions of YAP and TAZ in the podocyte by identifying podocyte-specific interactors. We generated stable heat sensitive mouse podocytes (hsMPs) carrying a single copy integration of a transgenic construct expressing a flagged version of mouse Yap (3XFLAG.YAP), Taz (3XFLAG.TAZ) or Ruby (3XFLAG.RUBY) in the Rosa26 locus. To explore the interactome of YAP and TAZ in podocytes we immunoprecipitated the tagged proteins and characterized the co-immunoprecipitated protein complexes by mass spectrometry. Within the interactome analyses of the hsMPs, we identified shared and non-shared interacting proteins between YAP and TAZ. Among these identified proteins many well established interactors of YAP and TAZ were included, like proteins of the Tead family, different angiomotins or large tumor suppressor kinase 1 (Lats1). Strikingly, among the shared proteins were numerous proteins of the nuclear shuttling machinery, like importins (Ipo), exportins (Xpo), transportins (Tnpo) and nucleoporins (Nup) that form the nuclear pore complex (NPC), such as NUP107, NUP133, NUP205 and XPO5.
Project description:The Hippo pathway plays a crucial in organ size control during development and tissue homeostasis in adult life. To examine a role for Hippo signaling in the intestinal epithelium, we analyzed gene expression patterns in the mouse intestinal epithelilum transfected with siRNAs or expression plasmids for shRNAs targeting the Hippo pathway effectors, YAP and TAZ. We performed two independent series of experiments (siGFP (n=3) vs siYAP/siTAZ (n=3), and shLacZ (n=1) vs shYAP/shTAZ (n=1)). Control siRNA (siGFP), YAP/TAZ siRNAs, or expression plasmids for control shRNA (shLacZ) or YAP/TAZ shRNAs were introduced into the mouse intestinal epithelium by the newly-developed in vivo transfection method. Four days after transfection, intestinal epithelial cells were isolated from the tissues and total RNA was extracted.
Project description:Oral squamous cell carcinoma (OSCC) is a prevalent form of cancer that develops from the epithelium of the oral cavity. OSCC is on the rise worldwide, and death rates associated with the disease are particularly high. Despite progress in understanding of the mutational and expression landscape associated with OSCC, advances in deciphering these alterations for the development of therapeutic strategies have been limited. Further insight into the molecular cues that contribute to OSCC is therefore required. Here we show that the transcriptional regulators YAP (YAP1) and TAZ (WWTR1), which are key effectors of the Hippo pathway, drive pro-tumorigenic signals in OSCC. Regions of pre-malignant oral tissues exhibit aberrant nuclear YAP accumulation, suggesting that dysregulated YAP activity contributes to the onset of OSCC. Supporting this premise, we determined that nuclear YAP and TAZ activity drives OSCC cell proliferation, survival, and migration in vitro, and is required for OSCC tumor growth and metastasis in vivo. Global gene expression profiles associated with YAP and TAZ knockdown revealed changes in the control of gene expression implicated in pro-tumorigenic signaling, including those required for cell cycle progression and survival. Notably, the transcriptional signature regulated by YAP and TAZ significantly correlates with gene expression changes occurring in human OSCCs identified by The Cancer Genome Atlas (TCGA), emphasizing a central role for YAP and TAZ in OSCC biology. Expression profiling was conducted following the repression of the transcriptional regulators TAZ and YAP (YAP/TAZ) in human SCC2 oral cancer cells. Human SCC2 oral cancer cells were transfected with control siRNA, or siRNAs targeting TAZ, YAP, or YAP/TAZ for 48 hours. Total RNA from three independent experiments carried out on separate days was isolated and purified and the samples were then profiled on Affymetrix Human Gene 2.0 Chips at the Boston University Microarray Core. The expression profiles were processed and normalized using the Robust Multi-array Average (RMA) procedure (23) based on a custom Brainarray CDF (24). For each of the siRNA experiments, signatures of genes differentially expressed between treatment and corresponding siRNA control with an FDR q-value ?0.05 and a fold change ?2 were identified as either activated (up-regulated in control) or repressed (up-regulated in treatment). The overlap between the differentially expressed gene signatures was evaluated by Fisher test. Hierarchical gene and sample clustering was performed on the top 3000 genes with highest median absolute deviation (MAD; a robust version of the variance) across 12 samples, using “ward” as the agglomeration rule, and 1 minus Pearson correlation and Euclidean as the distance measures for genes and samples, respectively.
Project description:We conditionally knocked out both Yap and Taz in cranial neural crest (CNC) using the Wnt1Cre driver and sequenced mRNA from embryonic day 10.5 mandibles. Examination of mRNA level in E10.5 mandibular tissues from control and Wnt1Cre Taz and Yap dKO mutant.
Project description:The WWTR1(TAZ)-CAMTA1 and YAP1-TFE3 gene fusions are disease defining gene alterations for epithelioid hemangioendothelioma, a vascular cancer. The resultant fusion proteins fuse the C terminus of CAMTA1 and TFE3 in frame to the N terminus of TAZ and YAP, respectively. An unbiased BioID-mass spectrometry/RNAi screen identified YEATS2 and ZZZ3 as components of the Ada2a-containing histone acetyltransferase complex and key interactors of both TAZ-CAMTA1 and YAP-TFE3. An integrative NGS approach including RNA-Seq, ChIP-Seq, and ATAC-Seq showed TAZ-CAMTA1 and YAP-TFE3 transcriptional programs overlap with TAZ and YAP but also drive expression of a novel transcriptome.
Project description:Uncontrolled Transforming growth factor-beta (TGFβ) signaling promotes aggressive metastatic properties in late-stage breast cancers. However, how TGFβ-mediated cues are directed to induce late-stage tumorigenic events is poorly understood, particularly given that TGFβ has clear tumor suppressing activity in other contexts. Here we demonstrate that the transcriptional regulators TAZ and YAP (TAZ/YAP), key effectors of the Hippo pathway, are necessary to promote and maintain TGFβ-induced tumorigenic phenotypes in breast cancer cells. Interactions between TAZ/YAP, TGFβ-activated SMAD2/3, and TEAD transcription factors reveal convergent roles for these factors in the nucleus. Genome-wide expression analyses indicate that TAZ/YAP, TEADs and TGFβ-induced signals coordinate a specific pro-tumorigenic transcriptional program. Importantly, genes cooperatively regulated by TAZ/YAP, TEAD, and TGFβ, such as the novel targets NEGR1 and UCA1, are necessary for maintaining tumorigenic activity in metastatic breast cancer cells. Nuclear TAZ/YAP also cooperate with TGFβ signaling to promote phenotypic and transcriptional changes in non-tumorigenic cells to overcome TGFβ repressive effects. Our work thus identifies crosstalk between nuclear TAZ/YAP and TGFβ signaling in breast cancer cells, revealing novel insight into late-stage disease-driving mechanisms. Expression profiling was conducted following the repression of the transcriptional regulators TAZ and YAP (TAZ/YAP), the TEAD family of transcription factors (TEAD1/2/3/4), or the TGFb signaling pathway (with SB-431542, an inhibitor of the TBRI recpeptor) in human MDA-MB-231-LM2 breast cancer cells treated with TGFβ1. Human MDA-MB-231-LM2-4 breast cancer cells were transfected with control siRNA, or siRNAs targeting TAZ/YAP or all four TEADs and were treated 24 hours later with 500pM TGFβ1 or 5mM SB-431542 for an additional 24 hours. Total RNA was isolated and twelve microarrays in total were performed, with each condition carried out three times on separate days. The Boston University Microarray Core generated the data using the Affymetrix Human Gene 1.0 St Array.