Project description:RNA helicase A (RHA) binds its target transcripts at the post-transcriptional control element (PCE) located in the 5’ untranslated region (UTR). This interaction represents an “RNA switch” that regulates protein synthesis. Down regulation of RHA by siRNAs was used to identify transcripts with RHA-dependent translation. Reduced accumulation of RNA in polysomes was monitored with microarrays.
Project description:RNA helicase A (RHA) binds its target transcripts at the post-transcriptional control element (PCE) located in the 5’ untranslated region (UTR). This interaction represents an “RNA switch” that regulates protein synthesis. Down regulation of RHA by siRNAs was used to identify transcripts with RHA-dependent translation. Reduced accumulation of RNA in polysomes was monitored with microarrays. Cytoplasmic lysates of cells treated with RHA targeted or non-silencing control siRNAs were separated by sucrose density gradient centrifugation. Ribosomal RNA profiles were generated, containing heavy polysomes were collected, and RNA was extracted.
Project description:RNA helicase A (RHA) binds its target transcripts at the post-transcriptional control element (PCE) located in the 5’ untranslated region (UTR). This interaction represents an “RNA switch” that regulates protein synthesis. Down regulation of RHA by siRNAs was used to identify transcripts with RHA-dependent translation. Reduced accumulation of RNA in polysomes was monitored with microarrays. Changes in cytoplasmic RNA steady state abundance was monitored as well. Sixty nine genes exhibit decreased transcript polysome association when subjected to RHA downregulation. A majority of the transcripts that experienced a reduction in the polysome fraction had no significant change in their cytoplasmic abundance (45 genes). Keywords: gene expression array-based
Project description:RNA helicase A (RHA) binds its target transcripts at the post-transcriptional control element (PCE) located in the 5â?? untranslated region (UTR). This interaction represents an â??RNA switchâ?? that regulates protein synthesis. Down regulation of RHA by siRNAs was used to identify transcripts with RHA-dependent translation. Reduced accumulation of RNA in polysomes was monitored with microarrays. Changes in cytoplasmic RNA steady state abundance was monitored as well. Sixty nine genes exhibit decreased transcript polysome association when subjected to RHA downregulation. A majority of the transcripts that experienced a reduction in the polysome fraction had no significant change in their cytoplasmic abundance (45 genes). Keywords: gene expression array-based Cytoplasmic lysates of cells treated with RHA targeted or non-silencing control siRNAs were separated by sucrose density gradient centrifugation. Ribosomal RNA profiles were generated, fractions containing polysomes were collected, and RNA was extracted.
Project description:This SuperSeries is composed of the following subset Series: GSE14055: Changes in polysome loading as a consequence of RHA downregulation GSE14056: Co-immunoprecipitation of RNAs with RNA helicase A (RHA) Refer to individual Series
Project description:RNA unwinding by DExH-type helicases underlies most RNA metabolism and function. It remains unresolved if and how the basic unwinding reaction of helicases is regulated by auxiliary domains. We explored the interplay between the RecA and auxiliary domains of the RNA helicase maleless (MLE) from Drosophila, using a suite of structural and functional studies. We discovered that MLE exists in a dsRNA bound open conformation and the auxiliary dsRBD2 domain aligns the substrate RNA with the accessible helicase tunnel. In an ATP-dependent manner, dsRBD2 associates with the helicase module, leading to tunnel closure around ssRNA. Furthermore, our structures provide a rationale for blunt ended dsRNA unwinding and 3’-5’ translocation by MLE. Structure-based MLE mutations confirm the functional relevance of our model for RNA unwinding. Our findings contribute to our understanding of fundamental mechanics of auxiliary domains in DExH helicase MLE which serves as model for its human ortholog and potentially therapeutic target, DHX9/RHA.
Project description:Given that RHA regulates translation by binding a PCE located at the 5’ UTR of the target transcripts a genome-wide screen was performed to identify mRNAs that bind RHA in vivo. The results from four experiments with samples obtained in four independent RNA immunoprecipitations identified 375 transcripts that co-immunoprecipitate with FLAG RHA.
Project description:Given that RHA regulates translation by binding a PCE located at the 5’ UTR of the target transcripts a genome-wide screen was performed to identify mRNAs that bind RHA in vivo. The results from duplicate experiments with samples obtained in two independent RNA immunoprecipitations identified 407 transcripts that co-immunoprecipitate with FLAG RHA. Keywords: gene expression array-based
Project description:Given that RHA regulates translation by binding a PCE located at the 5’ UTR of the target transcripts a genome-wide screen was performed to identify mRNAs that bind RHA in vivo. The results from four experiments with samples obtained in four independent RNA immunoprecipitations identified 375 transcripts that co-immunoprecipitate with FLAG RHA. Since N-terminal FLAG tagged RHA specifically co-immunoprecipitates PCE-containing mRNAs HEK293 cells were transfected with a CMV-FLAG-RHA construct. Cytoplasmic lysates were immunoprecipitated with anti-FLAG beads. RNA was extracted from the immunoprecipitate and used to probe a human Agilent expression arrays. An immunoprecipitation with cells transfected with empty FLAG plasmid was used as negative control.