BIOL 314 Lecture Notes - Tight Junction, Hmga2, Zeb2
27 Feb 2014
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Document Summary
Can also be seen in mammalian cells. mirsc recruits deadenylase to remove poly-a tail which stabilises mrna, preventing degradation. Unit responsible for interference in the rnai pathway. Sirna stabilized by argonaute proteins in risc. Like mirna, sirnas scan the entire transcriptome (mrnas). Piwi domain cleaves mrna by slicer activity. May have multiple targets, usually control gene networks. For humans: often found in fragile sites and genomic regions involved ion cancers. Encodes small rnas with antisense complementarity to lin-14. Lin-4 base pairs to 7 parts of lin-14. Aid in translational repression by mirna mirna cascade (endogenous) Lin-4l precursor folds like a hairpin, making dsrna. Lin-4 has partial complimentarity with lin14 3"utr. Drosha cleaves pri-mirna transcript into pre-mirna hairpin. Dicer matures it into sirna duplex by cleaving off hairpin. Mirnas bind at 3", recruit deadenylation complex. Mrna is destabilized but not degraded: controlled repression. Stronger base pairing brings risk to utr. 3" utrs do not have orf, highly structured rna balls.
