This Alu element mediated gene regulation exists in most cells, however, it is not operational in human embryonic stem cells (hESCs). In hESCs, the editing activity is robust and proteins involved in this pathway are all expressed, but the retention associated nuclear structures, called paraspeckles, are absent and only appear as cells differentiate. Paraspeckle assembly and function depends on the expression of a long nuclear-retained noncoding RNA, hNEAT1. This RNA is not expressed in hESCs, but is induced upon differentiation. Knockdown of hNEAT1 in HeLa cells results in both the loss of paraspeckles and the enhanced nucleocytoplasmic export of mRNAs containing inverted Alu repeats in their 3'-UTRs. Taken together, these results assign a novel biological function to a large noncoding nuclear RNA and also demonstrate that hESCs allow the nucleocytoplasmic export of structured mRNAs that are retained in the nuclei of differentiated cells.... strand cDNA was synthesized at 55AdC for 50 min according to the manufacturera#39;s manual (SuperscriptTM III, Invitrogen). ... with Taq DNA polymerase (Invitrogen), and PCR products were subcloned using the TOPO TA cloning kit (Invitrogen).
|Title||:||Novel Response to Double Stranded RNAs in Mammalian Cells|
|Publisher||:||ProQuest - 2009|