Project description:The purpose of the study was to identify mRNA bound to HuR in the presence of doxorubicin in MCF7 cells. We collected cytoplasmic RNA from untreated and treated cells and detected differentially expressed genes (DEGs). We also coimmunoprecipitated HuR and IgG (as control) from doxorubicin treated cells. Comparison between HuR RIP and IgG RIP signals was used to discriminate specific mRNA bound to HuR. HuR coimmmunoprecipitated material was hybridized together with cytoplasmic mRNA of doxorubicin treated cells, enabling the fold enrichment calculation and the selection of mRNAs bound to HuR. Keywords: RIP-Chip, HuR, doxorubicin, MCF7, HuR consensus binding, post-transcriptional regulation. We subjected MCF7 cells to starvation for 24h and then we added doxorubicin at final concentration of 10 uM, profiling before and after 4 hours of treatment in biological quadruplicate (only on cytoplasmic mRNAs, as HuR was found in the cytoplasm). Differentially expressed genes, altered during the treatment, were identified. Data derived from HuR RIP-Chip and IgG RIP-Chip (in biological quadruplicate) allowed the identification of specific mRNAs bound to HuR. The comparison between HuR RIP-Chip and cytoplasmic extracts from doxorubicin treated cells (in biological triplicate) identified those genes that were more strictly bound to HuR independently from their expression levels.
Project description:The purpose of the study was to identify mRNA bound to HuR in the presence of doxorubicin in MCF7 cells. We collected cytoplasmic RNA from untreated and treated cells and detected differentially expressed genes (DEGs). We also coimmunoprecipitated HuR and IgG (as control) from doxorubicin treated cells. Comparison between HuR RIP and IgG RIP signals was used to discriminate specific mRNA bound to HuR. HuR coimmmunoprecipitated material was hybridized together with cytoplasmic mRNA of doxorubicin treated cells, enabling the fold enrichment calculation and the selection of mRNAs bound to HuR. Keywords: RIP-Chip, HuR, doxorubicin, MCF7, HuR consensus binding, post-transcriptional regulation.
Project description:Integrative regulatory mapping indicates that the RNA-binding protein HuR (ELAVL1) couples pre-mRNA processing and mRNA stability In this dataset, we employed two distinct experiments. 1) HuR RIP-chip to identify mRNA targets of HuR. 2) HuR knockdown to identify mRNAs whose expression are dependent on HuR. All 12 samples were normalized with PLIER using Affymetrix power tools. To identify RNA targets of HuR, HuR RIP samples were compared to Mock RIP samples. To identify RNA regulated by HuR, HuR knockdown samples were compared to mock knockdown samples.
Project description:Integrative regulatory mapping indicates that the RNA-binding protein HuR (ELAVL1) couples pre-mRNA processing and mRNA stability In this dataset, we employed two distinct experiments. 1) HuR RIP-chip to identify mRNA targets of HuR. 2) HuR knockdown to identify mRNAs whose expression are dependent on HuR.
Project description:Elavl1/HuR is a ubiquitous and conserved RNA-binding protein that binds to a U-rich RNA motif that shuttles between nucleus and cytoplasm. In epithelia, the elevated expression of HuR assumingly promotes degeneration and cancer suggesting that its generic suppression may provide clinical benefits. In this study we focused on biological and clinical functions of HuR in intestinal epithelial cells and we presented evidence that changes in HuR levels induce polarized distortions in these cells to support different pathologic outcomes. In this experiment we investigate Elavl1 targets via Elavl1 Immunopercipitation (RIP-chip) by arrays and compare relative to background. Control and TgATF-HuR mice were treated with Dimethylhydrazine (DMH)/Dextran Sodium Sulphate (DSS) for 60 days and tumors where dissected from large intestines; those with sizes between 10-15mm2 were pooled to generate samples with 4 tumors/sample and snap frozen. Three samples per genotype were used either for RIP analyses or total RNA extraction. Isolated RNA was used for microarray or qRT-PCR analyses.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.
Project description:Analysis of RNA immunoprecipitation of HuR, a RNA binding protein (RBP), in breast cancer cell lines. This approach, utilizing RNA immunoprecipitation hybridized to microarray (RIP-Chip), provides global identification of putative endogenous mRNA targets of different RBPs. HuR is an RBP that binds to the AU-rich (ARE) regions of labile mRNAs, such as proto-oncogenes, facilitating their translation into protein. HuR has been shown to play a role in cancer progression and elevated levels of cytoplasmic HuR directly correlate with increased invasiveness and poor prognosis for many cancers, including those of the breast. We used HuR RIP-Chip as a comprehensive and systematic method to survey breast cancer target genes in both MCF-7 (estrogen receptor positive, ER+) and MDA-MB-231 (estrogen receptor negative, ER-) breast cancer cell lines. We identified unique subsets of HuR associated mRNAs found individually or in both cell types. Two novel HuR targets, CD-9 and CALM-2, were identified and validated by quantitative RT-PCR and biotin pulldown analysis. Our findings reveal that the differential regulation of these two cancer-related genes by HuR was contingent upon the cellular environment. RNA immunoprecipitation of the HuR RNA binding protein by 3A2 antibody and IgG (control) from two human breast cancer cell lines, MCF-7 and MDA-MB-231 .