Nat Struct Mol Biol
March 2023
Deadenylation generally constitutes the first and pivotal step in eukaryotic messenger RNA decay. Despite its importance in posttranscriptional regulations, the kinetics of deadenylation and its regulation remain largely unexplored. Here we identify La ribonucleoprotein 1, translational regulator (LARP1) as a general decelerator of deadenylation, which acts mainly in the 30-60-nucleotide (nt) poly(A) length window.
View Article and Find Full Text PDFSecondary small interfering RNA (siRNA) production, triggered by primary small RNA targeting, is critical for proper development and antiviral defense in many organisms. RNA-dependent RNA polymerase (RDR) is a key factor in this pathway. However, how RDR specifically converts the targets of primary small RNAs into double-stranded RNA (dsRNA) intermediates remains unclear.
View Article and Find Full Text PDFRNA-dependent RNA polymerases (RdRPs) in eukaryotes convert single-stranded RNAs into double-stranded RNAs, thereby amplifying small interfering RNAs that play crucial roles in the regulation of development, maintenance of genome integrity and antiviral immunity. Here, we describe a method of RdRP assay using recombinant RDR6 prepared by an insect expression system. By using this classical biochemical assay, we revealed that RDR6 has a strong template preference for RNAs lacking a poly(A) tail.
View Article and Find Full Text PDFIt remains unclear how post-transcriptional gene silencing (PTGS) in plants discriminates aberrant RNAs from canonical messenger RNAs (mRNAs). The key step of plant PTGS is the conversion of aberrant RNAs into double-stranded RNAs by RNA-DEPENDENT RNA POLYMERASE6 (RDR6). Here, we show that RDR6 itself selects aberrant poly(A)-less mRNAs over canonical polyadenylated mRNAs as templates at the initiation step of complementary strand synthesis.
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