The Rad23/Rad4 protein complex plays a major role in DNA damage recognition during nucleotide excision repair (NER) in yeast. We recently showed that two distinct pathways contribute to efficient NER in yeast. The first operates independently of de novo protein synthesis and requires a nonproteolytic function of the 19S regulatory complex of the 26S proteasome and Rad23. The second pathway requires de novo protein synthesis, and relies on the activity of a newly identified Rad7-containing E3 ubiquitin ligase that ubiquitinates Rad4 in response to UV. Surprisingly, we found that cells deleted of either Rad23 or Rad4 caused reduced Rad4 and Rad23 mRNA levels respectively. We considered the possibility of an unexpected role of Rad23 and Rad4 in regulating the expression of genes involved in the transcriptional response to DNA damage. Gene expression profiling has suggested that Rad23 and Rad4 may function as a complex to affect transcription of a small subset of genes in response to UV damage. To determine how Rad4 and Rad23 contribute to the regulation of these genes, we have examined the occupancy of Rad4/Rad23 in their promoter regions by chromatin immunoprecipitation (ChIP), both in the presence and absence of UV damage. Our preliminary ChIP data suggests that the Rad4/Rad23 complex regulates a set of genes in response to UV light. We also proposed that the transcriptional regulatory activity of the Rad4-Rad23 complex required Rad4 ubiquitination. These arrays test this theory using the psocs mutant strain, which is unable to facilitate Rad4 ubiquitination after UV irradiation.
UV induced ubiquitination of the yeast Rad4-Rad23 complex promotes survival by regulating cellular dNTP pools.
Time
View SamplesThe Rad23/Rad4 protein complex plays a major role in DNA damage recognition during nucleotide excision repair (NER) in yeast. We recently showed that two distinct pathways contribute to efficient NER in yeast. The first operates independently of de novo protein synthesis and requires a nonproteolytic function of the 19S regulatory complex of the 26S proteasome and Rad23. The second pathway requires de novo protein synthesis, and relies on the activity of a newly identified E3 ubiquitin ligase that ubiquitinates Rad4 in response to UV. Surprisingly, we found that cells deleted of either Rad23 or Rad4 caused reduced Rad4 and Rad23 mRNA levels respectively. We considered the possibility of an unexpected role of Rad23 and Rad4 in regulating the expression of genes involved in the transcriptional response to DNA damage. Gene expression profiling has suggested that Rad23 and Rad4 may function as a complex to affect transcription of a small subset of genes in response to UV damage. To determine how Rad4 and Rad23 contribute to the regulation of these genes, we have examined the occupancy of Rad4/Rad23 in their promoter regions by chromatin immunoprecipitation (ChIP), both in the presence and absence of UV damage. Our preliminary ChIP data suggests that the Rad4/Rad23 complex regulates a set of genes in response to UV light.
UV induced ubiquitination of the yeast Rad4-Rad23 complex promotes survival by regulating cellular dNTP pools.
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View SamplesBACKGROUND: Hox genes are implicated in hematopoietic stem cell (HSC) regulation as well as in leukemia development through translocation with the nucleoporin gene NUP98. Interestingly, an engineered NUP98-HOXA10 (NA10) fusion can induce a several hundred-fold expansion of HSCs in vitro and NA10 and the AML-associated fusion gene NUP98-HOXD13 (ND13) have a virtually indistinguishable ability to transform myeloid progenitor cells in vitro and to induce leukemia in collaboration with MEIS1 in vivo. METHODOLOGY/PRINCIPAL FINDINGS: These findings provided a potentially powerful approach to identify key pathways mediating Hox-induced expansion and transformation of HSCs by identifying gene expression changes commonly induced by ND13 and NA10 but not by a NUP98-Hox fusion with a non-DNA binding homedomain mutation (N51S). The gene expression repertoire of purified murine bone marrow Sca-1+Lin- cells transduced with retroviral vectors encoding for these genes was established using the Affymetrix GeneChip MOE430A. Approximately seventy genes were differentially expressed in ND13 and NA10 cells that were significantly changed by both compared to the ND13(N51S) mutant. Intriguingly, several of these potential Hox target genes have been implicated in HSC expansion and self-renewal, including the tyrosine kinase receptor Flt3, the prion protein, Prnp, hepatic leukemia factor, Hlf and Jagged-2, Jag2. CONCLUSIONS: In conclusion this study has identified several novel Hox downstream target genes and provides important new leads to key regulators of the expansion and transformation of hematopoietic stem cells by Hox.
Candidate genes for expansion and transformation of hematopoietic stem cells by NUP98-HOX fusion genes.
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View SamplesPolycomb-mediated repression of Dkk-1 activates Wnt signaling and enhances tumorigenic potential of lung cancer cells following tobacco smoke exposure
Tobacco smoke induces polycomb-mediated repression of Dickkopf-1 in lung cancer cells.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Complementary strand microRNAs mediate acquisition of metastatic potential in colonic adenocarcinoma.
Sex
View SamplesCompariosn of mRNA and miRNA profile in colon cancer
Complementary strand microRNAs mediate acquisition of metastatic potential in colonic adenocarcinoma.
Sex
View SamplesA key limitation in single cell genomics is generating a high-quality single cell suspension that contains rare or difficult to dissociate cell types and is free of RNA degradation or transcriptional stress responses. Samples with unpredictable availability or that must be collected at several timepoints present additional challenges. Using adult mouse kidney, we compared single-cell RNA sequencing (scRNA-seq) data generated using DropSeq with snRNA-seq data generated from nuclei using sNuc-DropSeq, DroNc-seq and 10X Chromium. We validated snRNA-seq on fibrotic kidney from day 14 unilateral ureteral obstruction (UUO). Overall design: Dropseq, sNucDropseq, DroNcSeq and 10X Chromium were used to profile mouse healthy and fibrotic kidneys
Advantages of Single-Nucleus over Single-Cell RNA Sequencing of Adult Kidney: Rare Cell Types and Novel Cell States Revealed in Fibrosis.
Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Inhibition of cancer cell proliferation by PPARγ is mediated by a metabolic switch that increases reactive oxygen species levels.
Specimen part, Cell line
View SamplesMicroarray studies was performed to analyze gene expression changes in NCI-H2347 cells after treatment with 50 M pioglitazone for 12hr, 24hr and 48hrs.
Inhibition of cancer cell proliferation by PPARγ is mediated by a metabolic switch that increases reactive oxygen species levels.
Specimen part, Cell line
View SamplesMouse haematopoietic stem cells (HSCs) undergo a post-natal transition in several properties, including a marked reduction in their self-renewal activity. We now show that the developmentally timed change in this key function of HSCs is associated with their decreased expression of Lin28b and an accompanying increase in their let-7 microRNA levels. Lentivirus(LV)-mediated overexpression of Lin28 in adult HSCs elevates their self-renewal activity in transplanted irradiated hosts, as does overexpression of Hmga2, a well-established let-7 target that is upregulated in fetal HSCs. Conversely, HSCs from fetal Hmga2-/- mice do not display the heightened self-renewal activity that is characteristic of wild-type fetal HSCs. Interestingly, overexpression of Hmga2 in adult HSCs does not mimic the ability of elevated Lin28 to activate a fetal lymphoid differentiation program. Thus Lin28b may act as a master regulator of developmentally timed changes in HSC programs with Hmga2 serving as its specific downstream modulator of HSC self-renewal potential.
The Lin28b-let-7-Hmga2 axis determines the higher self-renewal potential of fetal haematopoietic stem cells.
Specimen part
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