Term
| How can antisense RNAs control translation? |
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Definition
| By binding to their complementary sequences and preventing reading of the start codon |
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Term
| What are stand alone lnc-RNAs |
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Definition
| Distinct transcription units with no overlap with protein coding genes |
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Term
| What are natural antisense transcripts |
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Definition
| Transcription that is opposite the sense DNA strand of annotated transcription units |
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Term
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Definition
| Genes that have lost their coding potential due to mutations (2-20% can still be transcribed) |
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Term
| What are long intronice nc RNAs |
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Definition
| Large-scale transcripts encoded within the introns of annotated genes |
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Term
| What are Promoter enhancer associated transcripts? |
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Definition
| Produced from vicinity of start sites in both directions |
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Term
| What functions do lnc-RNAs have in the nucleus? |
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Definition
| scaffolds, aiding nuclear body formation, disruption of transcription machinery, chromosomal looping, splice site masking, thethers |
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Term
| What functions do lnc-RNAs have in the cytoplasm? |
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Definition
| decrease mRNA stability, distupt translation, mask mRNA sites, increase mRNA stability, localize transcription factors, compete for mRNA binding sites |
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Term
| What effects to sncRNAs normally have? |
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Definition
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Term
| Where are piwi RNAs normally found, and what is their role/ |
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Definition
| the germline, they repress target gene expression by directing MILI splicer activity against specific mRNAs (when complexed with piwi proteins) and exploit DNA methylation and chromatin remodelling as regulatory mechanisms. Have a role gonadal development. |
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Term
| What do miRNAs tend to regulate? |
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Definition
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Term
| What do siRNAs tend to do? |
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Definition
| Defend against invasive nucleic acids |
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Term
| How are siRNAs produced and what is their basic structure? |
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Definition
| dsRNA is processed by Dicer- an endoribonuclease, and consist of a guide strand and a passenger strand |
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Term
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Definition
| identify target via specific base pairing, then use slicer activity to cleave and degrade mRNAs |
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Term
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Definition
| processed from transcripts of independent genes or intron, before being processed by Drosha, which forms it into a hairpin., before being transported to the cytoplasm, where it is cleaved by dicer, produceing a 20nt miRNA duplex, one side of which is incorporated into the miRISC complex, the other strand is degraded or recycled |
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Term
| What are the core components of the miRNA induced silencing complex (miRISC)? |
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Definition
| Argonaute proteins, GW182, miRNAs |
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Term
| How does miRNA silence genes? |
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Definition
Post-initiation inhibition - AGO2 binds to target mRNA, inhibits the ribosome, the ribosome falls off
Repression of translation initiation - AGO2 bind to target mRNA, inhibits ribosome binding
Target mRNA destabilization, AGO2 binds, DCP1/DCP2 removes 7mG cap, exonucleases digest the rest |
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Term
| What is left behind after miRNA degredation? |
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Definition
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Term
| How are miRNA genes organized? |
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Definition
| In polycistronic clusters, from which several miRNAs can be co-expressed. These clusters seem to evolve rapidly - possibly for fine-tuning the targeting |
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