iCLIP Dotaz Zobrazit nápovědu
RNA-binding proteins (RBPs) are critical to posttranscriptional gene regulation. Therefore, characterization of the RNA molecules bound by RBPs in vivo represent a key step in elucidating their function. The recently developed iCLIP technique allows single nucleotide resolution of the RNA binding footprints of RBPs. We present the iCLIP technique modified for its application to Trypanosoma brucei and most likely other kinetoplastid flagellates. By using the immuno- or affinity purification approach, it was successfully applied to the analysis of several RBPs. Furthermore, we also provide a detailed description of the iCLIP/iCLAP protocol that shall be particularly suitable for the studies of trypanosome RBPs.
- MeSH
- imunoprecipitace metody MeSH
- nukleotidy genetika metabolismus MeSH
- parazitologie metody MeSH
- proteiny vázající RNA analýza genetika metabolismus MeSH
- protozoální proteiny analýza genetika metabolismus MeSH
- RNA protozoální genetika metabolismus MeSH
- RNA genetika metabolismus MeSH
- Trypanosoma brucei brucei genetika MeSH
- ultrafialové záření MeSH
- vazba proteinů genetika účinky záření MeSH
- vazebná místa genetika MeSH
- zobrazení jednotlivé molekuly metody MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
MRP1/2 is a heteromeric protein complex that functions in the trypanosomatid mitochondrion as part of the RNA editing machinery, which facilitates multiple targeted insertions and deletions of uridines. MRP1/2 was shown to interact with MRB8170, which initiates RNA editing by marking pre-edited mRNAs, while TbRGG2 is required for its efficient progression on pan-edited mRNAs. Both MRP1/2 and TbRGG2 are capable of modulating RNA-RNA interactions in vitro. As determined by using iCLIP and RIP-qPCR, RNAs bound to MRP1/2 are characterized and compared with those associated with MRB8170 and TbRGG2. We provide evidence that MRP1 and MRB8170 have correlated binding and similar RNA crosslinking peak profiles over minimally and never-edited mRNAs. Our results suggest that MRP1 assists MRB8170 in RNA editing on minimally edited mRNAs.
- MeSH
- editace RNA MeSH
- messenger RNA genetika metabolismus MeSH
- mitochondrie genetika metabolismus MeSH
- proteiny vázající RNA metabolismus MeSH
- protozoální proteiny genetika metabolismus MeSH
- RNA mitochondriální genetika metabolismus MeSH
- Trypanosoma genetika metabolismus MeSH
- vazba proteinů MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Replication-dependent histones (RDH) are required for packaging of newly synthetized DNA into nucleosomes during the S phase when their expression is highly upregulated. However, the mechanisms of this upregulation in metazoan cells remain poorly understood. Using iCLIP and ChIP-seq, we found that human cyclin-dependent kinase 11 (CDK11) associates with RNA and chromatin of RDH genes primarily in the S phase. Moreover, its amino-terminal region binds FLASH, an RDH-specific 3'-end processing factor, which keeps the kinase on the chromatin. CDK11 phosphorylates serine 2 (Ser2) of the carboxy-terminal domain of RNA polymerase II (RNAPII), which is initiated when RNAPII reaches the middle of RDH genes and is required for further RNAPII elongation and 3'-end processing. CDK11 depletion leads to decreased number of cells in S phase, likely owing to the function of CDK11 in RDH gene expression. Thus, the reliance of RDH expression on CDK11 could explain why CDK11 is essential for the growth of many cancers.
- MeSH
- chromatin genetika metabolismus MeSH
- cyklin-dependentní kinasy genetika metabolismus MeSH
- fosforylace MeSH
- genetická transkripce * MeSH
- histony genetika metabolismus MeSH
- lidé MeSH
- proteiny regulující apoptózu genetika metabolismus MeSH
- proteiny vázající vápník genetika metabolismus MeSH
- regulace genové exprese MeSH
- replikace DNA MeSH
- RNA genetika metabolismus MeSH
- S fáze MeSH
- serin metabolismus MeSH
- vazebná místa MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Many nascent long non-coding RNAs (lncRNAs) undergo the same maturation steps as pre-mRNAs of protein-coding genes (PCGs), but they are often poorly spliced. To identify the underlying mechanisms for this phenomenon, we searched for putative splicing inhibitory sequences using the ncRNA-a2 as a model. Genome-wide analyses of intergenic lncRNAs (lincRNAs) revealed that lincRNA splicing efficiency positively correlates with 5'ss strength while no such correlation was identified for PCGs. In addition, efficiently spliced lincRNAs have higher thymidine content in the polypyrimidine tract (PPT) compared to efficiently spliced PCGs. Using model lincRNAs, we provide experimental evidence that strengthening the 5'ss and increasing the T content in PPT significantly enhances lincRNA splicing. We further showed that lincRNA exons contain less putative binding sites for SR proteins. To map binding of SR proteins to lincRNAs, we performed iCLIP with SRSF2, SRSF5 and SRSF6 and analyzed eCLIP data for SRSF1, SRSF7 and SRSF9. All examined SR proteins bind lincRNA exons to a much lower extent than expression-matched PCGs. We propose that lincRNAs lack the cooperative interaction network that enhances splicing, which renders their splicing outcome more dependent on the optimality of splice sites.
