scholarly journals DNA methylation directs microRNA biogenesis in mammalian cells

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Ohad Glaich ◽  
Shivang Parikh ◽  
Rachel E. Bell ◽  
Keren Mekahel ◽  
Maya Donyo ◽  
...  

AbstractMicroRNA (miRNA) biogenesis initiates co-transcriptionally, but how the Microprocessor machinery pinpoints the locations of short precursor miRNA sequences within long flanking regions of the transcript is not known. Here we show that miRNA biogenesis depends on DNA methylation. When the regions flanking the miRNA coding sequence are highly methylated, the miRNAs are more highly expressed, have greater sequence conservation, and are more likely to drive cancer-related phenotypes than miRNAs encoded by unmethylated loci. We show that the removal of DNA methylation from miRNA loci leads to their downregulation. Further, we found that MeCP2 binding to methylated miRNA loci halts RNA polymerase II elongation, leading to enhanced processing of the primary miRNA by Drosha. Taken together, our data reveal that DNA methylation directly affects miRNA biogenesis.

2005 ◽  
Vol 13 (2) ◽  
pp. 135-144 ◽  
Author(s):  
Miki Hieda ◽  
Henry Winstanley ◽  
Philip Maini ◽  
Francisco J. Iborra ◽  
Peter R. Cook

2014 ◽  
Vol 35 (2) ◽  
pp. 468-478 ◽  
Author(s):  
Tristan T. Eifler ◽  
Wei Shao ◽  
Koen Bartholomeeusen ◽  
Koh Fujinaga ◽  
Stefanie Jäger ◽  
...  

Transcriptional cyclin-dependent kinases (CDKs) regulate RNA polymerase II initiation and elongation as well as cotranscriptional mRNA processing. In this report, we describe an important role for CDK12 in the epidermal growth factor (EGF)-induced c-FOS proto-oncogene expression in mammalian cells. This kinase was found in the exon junction complexes (EJC) together with SR proteins and was thus recruited to RNA polymerase II. In cells depleted of CDK12 or eukaryotic translation initiation factor 4A3 (eIF4A3) from the EJC, EGF induced fewer c-FOS transcripts. In these cells, phosphorylation of serines at position 2 in the C-terminal domain (CTD) of RNA polymerase II, as well as levels of cleavage-stimulating factor 64 (Cstf64) and 73-kDa subunit of cleavage and polyadenylation specificity factor (CPSF73), was reduced at the c-FOS gene. These effects impaired 3′ end processing of c-FOS transcripts. Mutant CDK12 proteins lacking their Arg-Ser-rich (RS) domain or just the RS domain alone acted as dominant negative proteins. Thus, CDK12 plays an important role in cotranscriptional processing of c-FOS transcripts.


2019 ◽  
Vol 47 (17) ◽  
pp. 9024-9036 ◽  
Author(s):  
Jered M Wendte ◽  
Jeremy R Haag ◽  
Olga M Pontes ◽  
Jasleen Singh ◽  
Sara Metcalf ◽  
...  

Abstract In plants, nuclear multisubunit RNA polymerases IV and V are RNA Polymerase II-related enzymes that synthesize non-coding RNAs for RNA-directed DNA methylation (RdDM) and transcriptional gene silencing. Here, we tested the importance of the C-terminal domain (CTD) of Pol IV’s largest subunit given that the Pol II CTD mediates multiple aspects of Pol II transcription. We show that the CTD is dispensable for Pol IV catalytic activity and Pol IV termination-dependent activation of RNA-DEPENDENT RNA POLYMERASE 2, which partners with Pol IV to generate dsRNA precursors of the 24 nt siRNAs that guide RdDM. However, 24 nt siRNA levels decrease ∼80% when the CTD is deleted. RNA-dependent cytosine methylation is also reduced, but only ∼20%, suggesting that siRNA levels typically exceed the levels needed for methylation of most loci. Pol IV-dependent loci affected by loss of the CTD are primarily located in chromosome arms, similar to loci dependent CLSY1/2 or SHH1, which are proteins implicated in Pol IV recruitment. However, deletion of the CTD does not phenocopy clsy or shh1 mutants, consistent with the CTD affecting post-recruitment aspects of Pol IV activity at target loci.


2020 ◽  
Vol 117 (35) ◽  
pp. 21785-21795 ◽  
Author(s):  
Susheel Sagar Bhat ◽  
Dawid Bielewicz ◽  
Tomasz Gulanicz ◽  
Zsuzsanna Bodi ◽  
Xiang Yu ◽  
...  

InArabidopsis thaliana, the METTL3 homolog, mRNA adenosine methylase (MTA) introducesN6-methyladenosine (m6A) into various coding and noncoding RNAs of the plant transcriptome. Here, we show that an MTA-deficient mutant (mta) has decreased levels of microRNAs (miRNAs) but accumulates primary miRNA transcripts (pri-miRNAs). Moreover, pri-miRNAs are methylated by MTA, and RNA structure probing analysis reveals a decrease in secondary structure within stem–loop regions of these transcripts inmtamutant plants. We demonstrate interaction between MTA and both RNA Polymerase II and TOUGH (TGH), a plant protein needed for early steps of miRNA biogenesis. Both MTA and TGH are necessary for efficient colocalization of the Microprocessor components Dicer-like 1 (DCL1) and Hyponastic Leaves 1 (HYL1) with RNA Polymerase II. We propose that secondary structure of miRNA precursors induced by their MTA-dependent m6A methylation status, together with direct interactions between MTA and TGH, influence the recruitment of Microprocessor to plant pri-miRNAs. Therefore, the lack of MTA inmtamutant plants disturbs pri-miRNA processing and leads to the decrease in miRNA accumulation. Furthermore, our findings reveal that reduced miR393b levels likely contributes to the impaired auxin response phenotypes ofmtamutant plants.


2000 ◽  
Vol 275 (32) ◽  
pp. 24375-24382 ◽  
Author(s):  
Mark Meininghaus ◽  
Rob D. Chapman ◽  
Manuela Horndasch ◽  
Dirk Eick

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