Plant nuclear genomes encode hundreds of predicted organellar RNA binding proteins, few of which have been connected with their physiological RNA substrates and functions. In fact, among the largest family of putative RNA binding proteins in plants, the pentatricopeptide repeat (PPR) family, no physiologically relevant RNA ligands have been firmly established. We used the chloroplast-splicing factor CAF1 to demonstrate the fidelity of a microarray-based method for identifying RNAs associated wit ...[more]
Project description:Identification of target transcripts for the putative chloroplast RNA binding protein CFM2 in Zea mays. CFM2 was immunoprecipitated from a chloroplast extract. Chloroplast extracts were prepared from WT tissue. RNA from the pellet and from the supernatant for each pulldown was labelled with different fluoro-dyes and hybridized onto an array covering the complete maize chloroplast genome. Messages enriched in the immunoprecipitate from WT tissue are likely targets for CFM2.
Project description:Co-immunoprecipitation of the maize pentatricopeptide protein PPR4 and extraction of bound RNA. RNA is labelled and hybridized to a maize chloroplast genome tiling array in order to identify target RNA species of PPR4.
Project description:Identification of target transcripts for the putative chloroplast RNA binding protein CRP1 in Zea mays. CRP1 was immunoprecipitated from a chloroplast extract. Chloroplast extracts were prepared from WT and CRP1-deficient tissue. RNA from the pellet and from the supernatant for each pulldown was labelled with different fluoro-dyes and hybridized onto an array covering the complete maize chloroplast genome. Messages enriched in the immunoprecipitate from WT tissue, but not enriched in mutant tissue are likely targets for CRP1.
Project description:OE17 and OE23 are chloroplast targeted proteins. RNA co-immunoprecipitation was performed using antibodies raised against these proteins. RNA from the pellet and from the supernatent for each pulldown was labeled with different fluoro-dyes.
Project description:Deletion of the flap loop in the Rp2 subunit of human RNAPII did not alter the ability of human RNAPII to initiate transcription or elongate the initiated transcripts in vivo and in vitro, and was also dispensable for elongation factor-mediated enhancement and inhibition of transcript elongation in vitro. ChIP:chip of wild-type and flap deletion human RNAPII revealed that the mutant RNAPII was not defective for promoter binding, initiation and elongation in vivo. Eight ChIP datasets were generated as log2(IP/input) fluorescence intensities using anti-FLAG IP of wild-type RPB2-FLAG cells in biological triplicate, anti-FLAG IP of delta-FL RPB2 FLAG cells in biological triplicate, and anti-RPB1 CTD, 8WG16 of both wild-type and delta-FL cells in biological duplicate. The two 8WG16- IP datasets were combined to measure the distribution of RPB1 signal.
Project description:OmpR is a DNA binding protein belonging to the OmpR/EnvZ two component system. This system is known to sense changes in osmolarity in Escherichia coli. Recently, OmpR in Salmonella enterica serovar Typhimurium was found to be activated by acidic pH and DNA relaxation. In this study, ChIP-on-chip was employed to ascertain the genome-wide distribution of OmpR in Salmonella Typhimurium and Escherichia coli in acidic and neutral pH. In addition we investigated the affect of DNA relaxation on OmpR binding in Salmonella Typhimurium. Analysis of OmpR binding at pH 7 and pH 4.5 in E-minimal medium in both SL1344 and CSH50. Three independent biological replicates at each pH 7 and pH 4.5 was performed. This was done in each strain background. DNA was immunopreciptated using an anti-FLAG anitbody which binds to flag-tagged OmpR in both strains. Two control ‘mock’ experiments were performed under the same culture condtions in each strain background; DNA was immunopreciptated using normal mouse IgG antibody. To analyse the effect of DNA relaxation onOmpR binding SL1344 was maintained in the exponential growth phase in LB broth with and without treatment with the drug novobiocin (25 μg/ml) for 40 min. This was peformed on two independent occasions. In all cases the experimental immunoprecipitated DNA was hybridised against the input DNA.