A non-canonical repressor function of JUN restrains YAP activity and suppresses YAP-dependent liver cancer growth [CUT&RUN]
Ontology highlight
ABSTRACT: The transcriptional coactivators YAP/TAZ are the critical downstream regulators of the Hippo pathway that regulate gene expression in response to changes in pathway activity, mainly by binding to TEAD transcription factors. Uncontrolled transcriptional output of YAP/TAZ can lead to rapid induction of aggressive tumor growth. AP-1 is a dimeric basic leucine zipper (bZIP) transcription factor complex with JUN and FOS proteins being the most abundant members of this family. Unlike FOS, JUN can also form homodimers, but in the cell, JUN presumably preferentially forms heterodimers with members of the FOS family, which act as potent transcriptional activators. Previous studies identified substantial co-occupancy of YAP/TAZ and AP-1 at genomic sites, and they demonstrated that JUN/FOS heterodimers cooperate with the YAP/TAZ and TEAD transcription factors to drive YAP/TAZ target gene expression. Here, we now elucidate a negative feedback mechanism in which high YAP activity is restrained by the recruitment of homodimeric JUN::JUN/NCOR1 repressor complexes and show that this noncanonical JUN function is part of a tumor suppressor mechanism in the liver.
Project description:The transcriptional coactivators YAP/TAZ are the critical downstream regulators of the Hippo pathway that regulate gene expression in response to changes in pathway activity, mainly by binding to TEAD transcription factors. Uncontrolled transcriptional output of YAP/TAZ can lead to rapid induction of aggressive tumor growth. AP-1 is a dimeric basic leucine zipper (bZIP) transcription factor complex with JUN and FOS proteins being the most abundant members of this family. Unlike FOS, JUN can also form homodimers, but in the cell, JUN presumably preferentially forms heterodimers with members of the FOS family, which act as potent transcriptional activators. Previous studies identified substantial co-occupancy of YAP/TAZ and AP-1 at genomic sites, and they demonstrated that JUN/FOS heterodimers cooperate with the YAP/TAZ and TEAD transcription factors to drive YAP/TAZ target gene expression. Here, we now elucidate a negative feedback mechanism in which high YAP activity is restrained by the recruitment of homodimeric JUN::JUN/NCOR1 repressor complexes and show that this noncanonical JUN function is part of a tumor suppressor mechanism in the liver.
Project description:The transcriptional coactivators YAP/TAZ are the critical downstream regulators of the Hippo pathway that regulate gene expression in response to changes in pathway activity, mainly by binding to TEAD transcription factors. Uncontrolled transcriptional output of YAP/TAZ can lead to rapid induction of aggressive tumor growth. AP-1 is a dimeric basic leucine zipper (bZIP) transcription factor complex with JUN and FOS proteins being the most abundant members of this family. Unlike FOS, JUN can also form homodimers, but in the cell, JUN presumably preferentially forms heterodimers with members of the FOS family, which act as potent transcriptional activators. Previous studies identified substantial co-occupancy of YAP/TAZ and AP-1 at genomic sites, and they demonstrated that JUN/FOS heterodimers cooperate with the YAP/TAZ and TEAD transcription factors to drive YAP/TAZ target gene expression. Here, we now elucidate a negative feedback mechanism in which high YAP activity is restrained by the recruitment of homodimeric JUN::JUN/NCOR1 repressor complexes and show that this noncanonical JUN function is part of a tumor suppressor mechanism in the liver.
Project description:The transcriptional coactivators YAP/TAZ are the critical downstream regulators of the Hippo pathway that regulate gene expression in response to changes in pathway activity, mainly by binding to TEAD transcription factors. Uncontrolled transcriptional output of YAP/TAZ can lead to rapid induction of aggressive tumor growth. AP-1 is a dimeric basic leucine zipper (bZIP) transcription factor complex with JUN and FOS proteins being the most abundant members of this family. Unlike FOS, JUN can also form homodimers, but in the cell, JUN presumably preferentially forms heterodimers with members of the FOS family, which act as potent transcriptional activators. Previous studies identified substantial co-occupancy of YAP/TAZ and AP-1 at genomic sites, and they demonstrated that JUN/FOS heterodimers cooperate with the YAP/TAZ and TEAD transcription factors to drive YAP/TAZ target gene expression. Here, we now elucidate a negative feedback mechanism in which high YAP activity is restrained by the recruitment of homodimeric JUN::JUN/NCOR1 repressor complexes and show that this noncanonical JUN function is part of a tumor suppressor mechanism in the liver.
Project description:The transcriptional coactivators YAP/TAZ are the critical downstream regulators of the Hippo pathway that regulate gene expression in response to changes in pathway activity, mainly by binding to TEAD transcription factors. Uncontrolled transcriptional output of YAP/TAZ can lead to rapid induction of aggressive tumor growth. AP-1 is a dimeric basic leucine zipper (bZIP) transcription factor complex with JUN and FOS proteins being the most abundant members of this family. Unlike FOS, JUN can also form homodimers, but in the cell, JUN presumably preferentially forms heterodimers with members of the FOS family, which act as potent transcriptional activators. Previous studies identified substantial co-occupancy of YAP/TAZ and AP-1 at genomic sites, and they demonstrated that JUN/FOS heterodimers cooperate with the YAP/TAZ and TEAD transcription factors to drive YAP/TAZ target gene expression. Here, we now elucidate a negative feedback mechanism in which high YAP activity is restrained by the recruitment of homodimeric JUN::JUN/NCOR1 repressor complexes and show that this noncanonical JUN function is part of a tumor suppressor mechanism in the liver.
Project description:The transcriptional coactivators YAP/TAZ are the critical downstream regulators of the Hippo pathway that regulate gene expression in response to changes in pathway activity, mainly by binding to TEAD transcription factors. Uncontrolled transcriptional output of YAP/TAZ can lead to rapid induction of aggressive tumor growth. AP-1 is a dimeric basic leucine zipper (bZIP) transcription factor complex with JUN and FOS proteins being the most abundant members of this family. Unlike FOS, JUN can also form homodimers, but in the cell, JUN presumably preferentially forms heterodimers with members of the FOS family, which act as potent transcriptional activators. Previous studies identified substantial co-occupancy of YAP/TAZ and AP-1 at genomic sites, and they demonstrated that JUN/FOS heterodimers cooperate with the YAP/TAZ and TEAD transcription factors to drive YAP/TAZ target gene expression. Here, we now elucidate a negative feedback mechanism in which high YAP activity is restrained by the recruitment of homodimeric JUN::JUN/NCOR1 repressor complexes and show that this noncanonical JUN function is part of a tumor suppressor mechanism in the liver.
Project description:The transcriptional coactivators YAP/TAZ are the critical downstream regulators of the Hippo pathway that regulate gene expression in response to changes in pathway activity, mainly by binding to TEAD transcription factors. Uncontrolled transcriptional output of YAP/TAZ can lead to rapid induction of aggressive tumor growth. AP-1 is a dimeric basic leucine zipper (bZIP) transcription factor complex with JUN and FOS proteins being the most abundant members of this family. Unlike FOS, JUN can also form homodimers, but in the cell, JUN presumably preferentially forms heterodimers with members of the FOS family, which act as potent transcriptional activators. Previous studies identified substantial co-occupancy of YAP/TAZ and AP-1 at genomic sites, and they demonstrated that JUN/FOS heterodimers cooperate with the YAP/TAZ and TEAD transcription factors to drive YAP/TAZ target gene expression. Here, we now elucidate a negative feedback mechanism in which high YAP activity is restrained by the recruitment of homodimeric JUN::JUN/NCOR1 repressor complexes and show that this noncanonical JUN function is part of a tumor suppressor mechanism in the liver.
Project description:The transcriptional coactivators YAP/TAZ are the critical downstream regulators of the Hippo pathway that regulate gene expression in response to changes in pathway activity, mainly by binding to TEAD transcription factors. Uncontrolled transcriptional output of YAP/TAZ can lead to rapid induction of aggressive tumor growth. AP-1 is a dimeric basic leucine zipper (bZIP) transcription factor complex with JUN and FOS proteins being the most abundant members of this family. Unlike FOS, JUN can also form homodimers, but in the cell, JUN presumably preferentially forms heterodimers with members of the FOS family, which act as potent transcriptional activators. Previous studies identified substantial co-occupancy of YAP/TAZ and AP-1 at genomic sites, and they demonstrated that JUN/FOS heterodimers cooperate with the YAP/TAZ and TEAD transcription factors to drive YAP/TAZ target gene expression. Here, we now elucidate a negative feedback mechanism in which high YAP activity is restrained by the recruitment of homodimeric JUN::JUN/NCOR1 repressor complexes and show that this noncanonical JUN function is part of a tumor suppressor mechanism in the liver.
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.
Project description:Angiogenesis, the process by which endothelial cells (ECs) form new blood vessels from existing ones, is intimately linked to the tissue's metabolic milieu and often occurs at nutrient-deficient sites. However, ECs rely on sufficient metabolic resources to support growth and proliferation. How endothelial nutrient acquisition and usage are regulated is unknown. Here we show that these processes are dictated by YAP/TAZ-TEAD – a transcriptional module whose function is highly responsive to changes in the tissue environment. ECs lacking YAP/TAZ or their transcriptional partners, TEAD1, 2, and 4 fail to divide, resulting in stunted vascular growth in mice. Conversely, activation of TAZ, the more abundant paralogue in ECs, boosts proliferation, leading to vascular hyperplasia. We find that YAP/TAZ promote angiogenesis by fueling nutrient mTORC1 signaling. By orchestrating the transcription of a repertoire of cell-surface transporters, YAP/TAZ-TEAD stimulate the import of amino acids and other essential nutrients, thereby enabling mTORC1 pathway activation. Dissociating mTORC1 from these nutrient inputs – elicited by the loss of Rag GTPases – inhibits mTORC1 activity and prevents YAP/TAZ-dependent vascular growth. These findings define a pivotal role for YAP/TAZ-TEAD in steering endothelial mTORC1 and illustrate the essentiality of coordinated nutrient fluxes in the vasculature.
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.