Project description:Five members of the Arabidopsis thaliana NF-YA gene family are strongly induced by several stress conditions via transcriptional and miR169-related posttranscriptional mechanisms. These transcription factors participate in gene regulation via two different mechanisms, one depending on binding to the CCAAT-box in the promoter of regulated genes and the other, independent of the CCAAT-box, in which NF-YA prevents the interaction of the NF-YB/YC heterodimer with transcription factors.
Project description:Five members of the Arabidopsis thaliana NF-YA gene family are strongly induced by several stress conditions via transcriptional and miR169-related posttranscriptional mechanisms. These transcription factors participate in gene regulation via two different mechanisms, one depending on binding to the CCAAT-box in the promoter of regulated genes and the other, independent of the CCAAT-box, in which NF-YA prevents the interaction of the NF-YB/YC heterodimer with transcription factors. Three biological and two technical (in swap) replicates for each genotype were obtained for each treatment (DMSO (mock) and estradiol 24h after induction). Mock samples were pooled and used as a reference.
Project description:Nuclear Factor Y (NF-Y) is a heterotrimeric transcription factor that binds CCAAT elements. The NF-Y trimer is composed of a Histone Fold Domain (HFD) dimer (NF-YB/NF-YC) and NF-YA, which confers DNA sequence specificity. NF-YA shares a conserved domain with the CONSTANS, CONSTANS-LIKE, TOC1 (CCT) proteins. We show that CONSTANS (CO/B-BOX PROTEIN1 BBX1), a master flowering regulator, forms a trimer with Arabidopsis thaliana NF-YB2/NF-YC3 to efficiently bind the CORE element of the FLOWERING LOCUS T promoter. Using saturation mutagenesis, electrophoretic mobility shift assays, and RNA-sequencing profiling of co, nf-yb, and nf-yc mutants, we identify CCACA elements as the core NF-CO binding site. CO physically interacts with the same HFD surface required for NF-YA association, as determined by mutations in NF-YB2 and NF-YC9, and tested in vitro and in vivo. The co-7 mutation in the CCT domain, corresponding to an NF-YA arginine directly involved in CCAAT recognition, abolishes NF-CO binding to DNA
Project description:The transcription factor NF-Y promotes cell proliferation and often loses its activity during differentiation through the regulation of NF-YA, the DNA binding subunit of the complex. In stem cell compartments, the shorter NF-YA splice variant (NF-YAs) is abundantly expressed and sustains their expansion. Here, we report that satellite cells, the stem cell population of adult skeletal muscle necessary for its growth and regeneration, express uniquely the longer NF-YA isoform (NF-YAl), majorly associated with cell differentiation. Through the generation of a conditional knock out mouse model that selectively ablates NF-YA in satellite cells, we demonstrate that NF-YA expression, and hence NF-Y activity, is fundamental to preserve the pool of muscle stem cells. Moreover, NF-Y supports their commitment to differentiation and ensures robust regenerative response to muscle injury. Gene expression profiling highlights an unexpected role for NF-Y in stem cell biology and opens a new scenario for NF-Y activity that is dispensable for muscle stem cell proliferation but required for efficient myogenic differentiation.
Project description:The polarization and activation of macrophages are controlled synergistically by transcription factors such as NF-κB and AP-1 transcription factor members. Surprisingly, little is known about the role of the Fra proteins, both members of the AP-1 transcription factor family, in macrophage activity. To determine the full profile of Fra network, microarray RNA expression analysis using Agilent Technologies platform was performed in wild-type, Fra-1ΔMxCre or Fra-2ΔLysMCre macrophages.
Project description:In contrast to stage-specific transcription factors, the role of ubiquitous transcription factors in neuronal development remains a matter of scrutiny. Here, we demonstrated that a ubiquitous factor NF-Y is essential for neural progenitor maintenance during brain morphogenesis. Deletion of the NF-YA subunit in neural progenitors by using nestin-cre transgene in mice resulted in significant abnormalities in brain morphology, including a thinner cerebral cortex and loss of striatum during embryogenesis. Detailed analyses revealed a progressive decline in multiple neural progenitors in the cerebral cortex and ganglionic eminences, accompanied by induced apoptotic cell death and reduced cell proliferation. In neural progenitors, the NF-YA short isoform lacking exon 3 is dominant and co-expressed with cell cycle genes. ChIP-seq analysis from the cortex during early corticogenesis revealed preferential binding of NF-Y to the cell cycle genes, some of which were confirmed to be downregulated following NF-YA deletion. Notably, the NF-YA short isoform disappears and is replaced by its long isoform during neuronal differentiation. Forced expression of the NF-YA long isoform in neural progenitors resulted in a significant decline in neuronal count, possibly due to the suppression of cell proliferation. Collectively, we elucidated a critical role of the NF-YA short isoform in maintaining neural progenitors, possibly by regulating cell proliferation and apoptosis. Moreover, we identified an isoform switch in NF-YA within the neuronal lineage in vivo, which may explain the stage-specific role of NF-Y during neuronal development.
Project description:In this RNA-seq experiment we identified genes differentially expressed in 12 hpf zebrafish embryos following disruption with dominant negative TALE (PBCAB) or NF-Y (NF-YA DN). We normalized each dominant negative condition to GFP. For PBCAB, we find 646 downregulated and 854 upregulated genes. For NF-YA DN, we find 325 downregulated and 577 upregulated genes. Genes downregulated by PBCAB are enriched for transcription, development, and homeodomain ontologies, while genes downregulated by NF-YA DN are enriched for transcription and cilia ontologies. 74 genes are downregulated by both PBCAB and NF-YA DN; these genes are enriched for transcription, development, and homeodomain ontologies.
Project description:Background: Approaches based on expression signatures of prostate cancer (PCa) have been proposed to predict patients’ outcomes and response to treatments. The transcription factor NF-Y participates to the progression from benign epithelium to both localized and metastatic PCa and is associated with aggressive transcriptional profile. The gene encoding for NF-YA, the DNA-binding subunit of NF-Y, produces two alternatively spliced transcripts, NF-YAs and NF-YAl. Bioinformatic analyses pointed at NF-YA splicing as a key transcriptional signature to discriminate between different tumor molecular subtypes. In this study, we aimed to determine the pathophysiological role of NF-YA splice variants in PCa and their association with aggressive PCa subtypes. Methods: Data on the expression of NF-YA isoforms were extracted from the TCGA (The Cancer Genome Atlas) database of tumor prostate tissues and validated in prostate cell lines. Through lentiviral transduction and CRISPR-Cas9 technology, we modulated the expression of NF-YA splice variants in prostate cancer cells. We investigated cellular and molecular effects on cancer programs through 2D/3D in vitro assays and RNA-seq profilings. The rank-rank hypergeometric overlap approach (RRHO) was used to identify concordant/discordant overlap between gene expression signatures of NF-YAs/NF-YAl cells and human PCa patients. We performed in vivo studies in SHO-SCID mice to determine pathological and molecular phenotypes of NF-YAs/NF-YAl xenograft tumors. Results: NF-YA depletion affects the tumorigenic potential of prostate cancer cells in vitro and in vivo. Elevated NF-YAs levels are associated to aggressive prostate cancer specimens, defined by Gleason Score and TNM classification. NF-YAl overexpression in prostate cancer cells increases cell motility, while NF-YAs enhances both cell proliferation and invasive properties in 3D cultured spheroids and xenograft tumors. NF-YAs-transcriptome of multi-cellular spheroids has an extensive overlap with both localized and metastatic human PCa signatures. The ratio between NF-YAs and NF-YAl transcripts is higher in LumB PAM50 subtype, characterized by poor prognosis, and stratification of patients based on NF-YAs expression is predictive of clinical outcome. Conclusions: Altogether, our results indicate that the modulation of NF-YA isoforms affects prostate pathophysiological processes and contributes to cancer-relevant phenotype, in vitro and in vivo. Evaluation of NF-YA splicing may represent a new molecular strategy for risk assessment of PCa patients.