Project description:To test the hypothesis that circRNAs might encode functional peptides in mammalian cells, we studied the long intergenic non-protein coding RNA, p53 induced transcript (LINC-PINT), which was previously reported as a tumor suppressor and connected p53 activation with polycomb repressive complex 2 (PRC2). We selected this long noncoding RNA (lncRNA) for further analysis because LINC-PINT has a long exon 2 which in accordance with the bioinformatical analyzed circular RNA standard.The following immunoblotting showed 87aa peptide level also decreased, indicating that this peptide is encoded by circPINTexon2. We name this circRNA encoded peptide PINT87aa. To investigate the possible regulatory role of PINT87aa, we did the expression micro array in PINT87aa stably transfect U251 or U87 glioblastoma cells and their control cells. The array analysis reveals that PINT87aa may involve in the cell cycle regulation, anti-apoptosis effects and multiple oncogenic signaling pathway activation.
Project description:In the cytoplasm, small RNAs can control mammalian translation by regulating the stability of mRNA. In the nucleus, small RNAs can also control transcription and splicing. The mechanisms for RNA-mediated nuclear regulation are not understood and remain controversial, hindering the effective application of nuclear RNAi and blinding investigation of its natural regulatory roles. Here we reveal that the human GW182 paralogs TNRC6A/B/C are central organizing factors critical to RNA-mediated transcriptional activation. Mass spectrometry of purified nuclear lysates followed by experimental validation demonstrates that TNRC6A interacts with proteins involved in protein degradation, RNAi, the CCR4-NOT complex, the mediator complex, and histone modifying complexes. Functional analysis implicates TNRC6A, NAT10, MED14, and WDR5 in RNA-mediated transcriptional activation. These findings describe protein complexes capable of bridging RNA-mediated sequence-specific recognition of noncoding RNA transcripts with the regulation of gene transcription.
Project description:To test the hypothesis that circRNAs might encode functional peptides in mammalian cells, we studied the long intergenic non-protein coding RNA, p53 induced transcript (LINC-PINT), which was previously reported as a tumor suppressor and connected p53 activation with polycomb repressive complex 2 (PRC2). We selected this long noncoding RNA (lncRNA) for further analysis because LINC-PINT has a long exon 2 which in accordance with the bioinformatical analyzed circular RNA standard.The following immunoblotting showed 87aa peptide level also decreased, indicating that this peptide is encoded by circPINTexon2. We name this circRNA encoded peptide PINT87aa.
Project description:Viroids are small circular highly structured pathogens infecting a broad range of plants, caus-ing economic losses. Since their discovery in the 70s, they have been considered as non-coding pathogens. In the last few years the discovery of other RNA entities, similar in terms of size and structure, that where shown to be translated (e.g cirRNAs, precursors of miRNA, RNA sat-ellites) as well as studies showing that some viroids are located in ribosomes, have reemerged the idea that viroids may be translated. In this study we used advanced bioinformatic analy-sis, in vitro experiments and LC-MS/MS to search for small viroid peptides of the Pospiviroidae PSTVd. Our results suggest that in our experimental conditions, even though the circular form of PSTVd is found in ribosomes, no produced peptides were identified. This indicates that the presence of PSTVd in ribosomes is most probably not related to peptide pro-duction but rather to another unknown function that requires further study