The NEET proteins mitoNEET (mNT) and nutrient-deprivation autophagy factor-1 (NAF-1) are required for cancer cell proliferation and resistance to oxidative stress. MitoNEET and NAF-1 are also implicated in a number of other human pathologies including diabetes, neurodegeneration and heart disease, as well as in development, differentiation and aging. Previous studies suggested that mNT and NAF-1 could function in the same pathway in cancer cells, preventing the over-accumulation of iron and reactive oxygen species (ROS) in mitochondria. Nevertheless, it is unknown whether these two proteins interact in cells, and how they mediate their function. Here we demonstrate, using yeast two-hybrid, in vivo bimolecular fluorescence complementation (BiFC), direct coupling analysis (DCA), RNA- sequencing, ROS and iron imaging, and single and double shRNA lines with suppressed mNT, NAF-1 and mNT/NAF-1 expression, that mNT and NAF-1 interact in cancer cells and function in the same cellular pathway. We further show using an in vitro cluster transfer assay that mNT can transfer its clusters to NAF-1. Our study suggests that mNT and NAF-1 could function as part of an iron-sulfur (2Fe-2S) cluster relay to maintain the levels of iron and Fe-S clusters under control in the mitochondria of cancer cells, thereby preventing the activation of apoptosis and/or autophagy and thus promoting rapid cellular proliferation. Overall design: Examination of the effect of suppression of mNT in the breast cancer cell line MCF-7. Two sample types were analyzed, MCF-7 suppressed for mNT and MCF-7 Empty vector control, three replicates for each.
Interactions between mitoNEET and NAF-1 in cells.
Specimen part, Cell line, Subject
View SamplesHepatic iron overload is a risk factor for progression of hepatocellular carcinoma (HCC), although the molecular mechanisms underlying this association have remained unclear. We now show that the iron-sensing ubiquitin ligase FBXL5 is previously unrecognized oncosuppressor in liver carcinogenesis in mice. Hepatocellular iron overload evoked by FBXL5 ablation gives rise to oxidative stress, tissue damage, inflammation and compensatory proliferation in hepatocytes and to consequent promotion of liver carcinogenesis induced by exposure to a chemical carcinogen. The tumor-promoting effect of FBXL5 deficiency in the liver is also operative in a model of virus-induced HCC. FBXL5-deficient mice thus constitute the first genetically engineered mouse model of liver carcinogenesis induced by iron overload. Dysregulation of FBXL5-mediated cellular iron homeostasis was also found to be associated with poor prognosis in human HCC, implicating FBXL5 plays a significant role in defense against hepatocarcinogenesis. Overall design: Total RNA was extracted from the nontumor and tumor tissue of an Alb-Cre/Fbxl5F/F male mouse (nontumor, n = 5; tumor, n = 5) or two littermate control Fbxl5F/F mice (nontumor, n = 6; tumor, n = 6) at 45 weeks of age.
Disruption of FBXL5-mediated cellular iron homeostasis promotes liver carcinogenesis.
Specimen part, Cell line, Subject
View SamplesYeast lacking the H3 or H4 amino termini, and corresponding wild type strains, were grown in synthetic media. These conditions induce Gcn4-activated transcription.
Contribution of the histone H3 and H4 amino termini to Gcn4p- and Gcn5p-mediated transcription in yeast.
No sample metadata fields
View SamplesAbf1 and Rap1 are General Regulatory Factors that contribute to transcriptional activation of a large number of genes, as well as to replication, silencing, and telomere structure in yeast. In spite of their widespread roles in transcription, the scope of their functional targets genome-wide has not been previously determined. We have used microarrays to examine the contribution of these essential GRFs to transcription genome-wide, by using ts mutants that dissociate from their binding sites at 37 C. We combined this data with published ChIP-chip studies and motif analysis to identify probable direct targets for Abf1 and Rap1. We also identified a substantial number of genes likely to bind Rap1 or Abf1, but not affected by loss of GRF binding. Interestingly, the results strongly suggest that Rap1 can contribute to gene activation from farther upstream than can Abf1. Also, consistent with previous work, more genes that bind Abf1 are unaffected by loss of binding than those that bind Rap1. Finally, we showed for several such genes that the Abf1 C-terminal region, which contains the putative activation domain, is not needed to confer this peculiar "memory effect" that allows continued transcription after loss of Abf1 binding.
Genome-wide analysis of transcriptional dependence and probable target sites for Abf1 and Rap1 in Saccharomyces cerevisiae.
No sample metadata fields
View SamplesSignal intensity data for rpd3 delete, H3delta(1-28), H3(K4,9,14,18,23,27Q), H4delta(2-26), H4(K5,8,12,16Q), rpd3 delete H3delta(1-28), and rpd3 delete H4(K5,8,12,16Q) yeast grown in rich (YPD) media
Genome-wide analysis of the relationship between transcriptional regulation by Rpd3p and the histone H3 and H4 amino termini in budding yeast.
No sample metadata fields
View SamplesDifferential gene expression between groups of homogenous cell types is a biological question whose time has come. RNA can be extracted from small numbers of cells, such as those isolated by laser capture microdissection, but the small amounts obtained often require amplification to enable whole genome transcriptome profiling by technologies such as microarray analysis and RNA-seq. Recently, advances in amplification procedures make amplification directly from whole cell lysates possible. The aim of this study was to compare two amplification systems for variations in observed RNA abundance attributable to the amplification procedure for use with small quantities of cells isolated by laser capture microdissection. Arabidopsis root cells undergoing giant cell formation due to nematode infestation and un-infested control root cells were laser captured and used to evaluate 2 amplification systems. One, NuGEN's WT-Ovation Pico amplification system, uses total RNA as starting material while the other, NuGEN's WT-One-Direct Amplification system, uses lysate containing the captured cells. The reproducibility of whole genome transcript profiling and correlations of both systems were investigated after microarray analysis. The NuGEN WT-Ovation One-Direct system was less reproducible and more variable than the NuGEN WT-Ovation Pico system. The NuGEN WT-Ovation Pico Amplification kit resulted in the detection of thousands of genes differentially expressed genes between giant cells and control cells. This is in marked contrast to the relatively few genes detected after amplification with the NuGEN WT-Ovation One-Direct Amplification kit.
Comparison between NuGEN's WT-Ovation Pico and one-direct amplification systems.
Specimen part, Time
View SamplesFzd2 is a Wnt receptor expressed in the embryonic lung. We made a conditional knockout of Fzd2 to specifically address the role of signaling through Fzd2 in lung epithelial development.
Wnt ligand/Frizzled 2 receptor signaling regulates tube shape and branch-point formation in the lung through control of epithelial cell shape.
Specimen part
View SamplesWe analysed the genexpression of dental follicle cells (DFCs) after 3 days osteogenic differentiation with BMP2 after transfection with a DLX3 plasmid (pDLX3) and after transfection with an empty plasmid (pEV)
A protein kinase A (PKA)/β-catenin pathway sustains the BMP2/DLX3-induced osteogenic differentiation in dental follicle cells (DFCs).
Specimen part
View SamplesConditional IRF8 KO mice (mice with a conditional allele of Irf8 crossed with CD19-Cre mice) showed increased numbers of both Gene expression data spleen marginal zone (MZ) and Gene expression data spleen follicular (FO) B cells compared to control mice.
IFN regulatory factor 8 restricts the size of the marginal zone and follicular B cell pools.
No sample metadata fields
View SamplesGene expression was compared for wild type yeast (BY4741) and yeast lacking Gal11/Med15 and Med3, or from a gal11-myc med3 strain. The gal11-myc allele shows a partial loss of function when combined with med3. Expression was analyzed for yeast grown in YPD as well as in CSM.
Distinct role of Mediator tail module in regulation of SAGA-dependent, TATA-containing genes in yeast.
No sample metadata fields
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