Project description:Adenovirus-transformed cells have a de-differentiated phenotype. Eliminating E1A in transformed human embryonic kidney cells de-repressed ~2600 genes, generating a gene expression profile closely resembling mesenchymal stem cells (MSC). This was associated with a dramatic change in cell morphology from one with scant cytoplasm and a globular nucleus to one with increased cytoplasm, extensive actin stress fibers and actomyosin-dependent flattening against the substratum. E1A-induced histone hypoacetylation by p300/CBP at H3K27/18 was reversed. Most of the increase in H3K27/18ac was near TEAD transcription factors associated with their co-activators YAP and TAZ regulated by the Hippo pathway. E1A causes YAP/TAZ cytoplasmic sequestration. After eliminating E1A, YAP/TAZ were transported into nuclei where they associated with poised enhancers with DNA-bound TEAD4 and H3K4me1. This activation of YAP/TAZ required RHO-family GTPase signaling and caused histone acetylation by p300/CBP, chromatin remodeling, and cohesin loading to establish MSC-associated enhancers and then super-enhancers. Consistent results were also observed in rat embryo kidney cells, human fibroblasts and human respiratory tract epithelial cells. These results together with earlier studies suggest that YAP/TAZ function in a developmental check-point controlled by signaling from the actin cytoskeleton that prevents differentiation of a progenitor cell until it is in the correct cellular and tissue environment.
Project description:Adenovirus-transformed cells have a de-differentiated phenotype. Eliminating E1A in transformed human embryonic kidney cells de-repressed ~2600 genes, generating a gene expression profile closely resembling mesenchymal stem cells (MSC). This was associated with a dramatic change in cell morphology from one with scant cytoplasm and a globular nucleus to one with increased cytoplasm, extensive actin stress fibers and actomyosin-dependent flattening against the substratum. E1A-induced histone hypoacetylation by p300/CBP at H3K27/18 was reversed. Most of the increase in H3K27/18ac was near TEAD transcription factors associated with their co-activators YAP and TAZ regulated by the Hippo pathway. E1A causes YAP/TAZ cytoplasmic sequestration. After eliminating E1A, YAP/TAZ were transported into nuclei where they associated with poised enhancers with DNA-bound TEAD4 and H3K4me1. This activation of YAP/TAZ required RHO-family GTPase signaling and caused histone acetylation by p300/CBP, chromatin remodeling, and cohesin loading to establish MSC-associated enhancers and then super-enhancers. Consistent results were also observed in rat embryo kidney cells, human fibroblasts and human respiratory tract epithelial cells. These results together with earlier studies suggest that YAP/TAZ function in a developmental check-point controlled by signaling from the actin cytoskeleton that prevents differentiation of a progenitor cell until it is in the correct cellular and tissue environment.
Project description:Adenovirus-transformed cells have a de-differentiated phenotype. Eliminating E1A in transformed human embryonic kidney cells de-repressed ~2600 genes, generating a gene expression profile closely resembling mesenchymal stem cells (MSC). This was associated with a dramatic change in cell morphology from one with scant cytoplasm and a globular nucleus to one with increased cytoplasm, extensive actin stress fibers and actomyosin-dependent flattening against the substratum. E1A-induced histone hypoacetylation by p300/CBP at H3K27/18 was reversed. Most of the increase in H3K27/18ac was near TEAD transcription factors associated with their co-activators YAP and TAZ regulated by the Hippo pathway. E1A causes YAP/TAZ cytoplasmic sequestration. After eliminating E1A, YAP/TAZ were transported into nuclei where they associated with poised enhancers with DNA-bound TEAD4 and H3K4me1. This activation of YAP/TAZ required RHO-family GTPase signaling and caused histone acetylation by p300/CBP, chromatin remodeling, and cohesin loading to establish MSC-associated enhancers and then super-enhancers. Consistent results were also observed in rat embryo kidney cells, human fibroblasts and human respiratory tract epithelial cells. These results together with earlier studies suggest that YAP/TAZ function in a developmental check-point controlled by signaling from the actin cytoskeleton that prevents differentiation of a progenitor cell until it is in the correct cellular and tissue environment.
Project description:Adenovirus transformed cells have a dedifferentiated phenotype. Eliminating E1A in transformed human embryonic kidney cells derepressed ∼2600 genes, generating a gene expression profile closely resembling mesenchymal stem cells (MSCs). This was associated with a dramatic change in cell morphology from one with scant cytoplasm and a globular nucleus to one with increased cytoplasm, extensive actin stress fibers, and actomyosin-dependent flattening against the substratum. E1A-induced hypoacetylation at histone H3 Lys27 and Lys18 (H3K27/18) was reversed. Most of the increase in H3K27/18ac was in enhancers near TEAD transcription factors bound by Hippo signaling-regulated coactivators YAP and TAZ. E1A causes YAP/TAZ cytoplasmic sequestration. After eliminating E1A, YAP/TAZ were transported into nuclei, where they associated with poised enhancers with DNA-bound TEAD4 and H3K4me1. This activation of YAP/TAZ required RHO family GTPase signaling and caused histone acetylation by p300/CBP, chromatin remodeling, and cohesin loading to establish MSC-associated enhancers and then superenhancers. Consistent results were also observed in primary rat embryo kidney cells, human fibroblasts, and human respiratory tract epithelial cells. These results together with earlier studies suggest that YAP/TAZ function in a developmental checkpoint controlled by signaling from the actin cytoskeleton that prevents differentiation of a progenitor cell until it is in the correct cellular and tissue environment.
Project description:The Hippo pathway downstream effectors, Yap and Taz, play key roles in cell proliferation and tissue growth, regulating gene expression especially via interaction with Tead transcription factors. To investigate their role in skeletal muscle stem cells, we analysed gene expression changes driven by Taz and compared these to Yap mediated changes to the transcriptome by measurement of gene expression on Affymetrix microarrays. To interrogate overlapping and unique transcriptional changes driven by these Hippo effectors, satellite cell-derived myoblasts were transduced with constitutively active TAZ S89A or YAP S127A retrovirus for 24h or 48h, with empty retrovirus as control. Triplicate microarray analyses of empty vector controls, hYAP1 S127A and TAZ S89A transgenic primary myoblasts were conducted.