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Argonaute 2 Binds Directly to tRNA Genes and Promotes Gene Repression in cis.

ABSTRACT: To further our understanding of the RNAi machinery within the human nucleus, we analyzed the chromatin and RNA binding of Argonaute 2 (AGO2) within human cancer cell lines. Our data indicated that AGO2 binds directly to nascent tRNA and 5S rRNA, and to the genomic loci from which these RNAs are transcribed, in a small RNA- and DICER-independent manner. AGO2 chromatin binding was not observed at non-TFIIIC-dependent RNA polymerase III (Pol III) genes or at extra-TFIIIC (ETC) sites, indicating that the interaction is specific for TFIIIC-dependent Pol III genes. A genome-wide analysis indicated that loss of AGO2 caused a global increase in mRNA expression level among genes that flank AGO2-bound tRNA genes. This effect was shown to be distinct from that of the disruption of DICER, DROSHA, or CTCF. We propose that AGO2 binding to tRNA genes has a novel and important regulatory role in human cells.

SUBMITTER: Woolnough JL

PROVIDER: S-EPMC4456445 | biostudies-literature | 2015 Jul

REPOSITORIES: biostudies-literature

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Argonaute 2 Binds Directly to tRNA Genes and Promotes Gene Repression in cis.

Woolnough Jessica L JL Atwood Blake L BL Giles Keith E KE

Molecular and cellular biology 20150701 13

To further our understanding of the RNAi machinery within the human nucleus, we analyzed the chromatin and RNA binding of Argonaute 2 (AGO2) within human cancer cell lines. Our data indicated that AGO2 binds directly to nascent tRNA and 5S rRNA, and to the genomic loci from which these RNAs are transcribed, in a small RNA- and DICER-independent manner. AGO2 chromatin binding was not observed at non-TFIIIC-dependent RNA polymerase III (Pol III) genes or at extra-TFIIIC (ETC) sites, indicating tha ...[more]

PMID: 25918241

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Argonaute 2 binds directly to tRNA genes and promotes gene repression in cis

Project description:To further our understanding of the RNAi machinery within the human nucleus, we analyzed the chromatin and RNA binding of Argonaute 2 (AGO2) within human cancer cell lines. Our data indicated that AGO2 binds directly to nascent tRNA and 5S rRNA, and to the genomic loci from which these RNAs are transcribed, in a small RNA- and DICER-independent manner. AGO2 chromatin binding was not observed at non-TFIIIC-dependent RNA polymerase (Pol) III genes or at extra-TFIIIC (ETC) sites, indicating that the interaction is specific for TFIIIC-dependent Pol III genes. A genome-wide analysis indicated that loss of AGO2 caused a global increase in the mRNA expression level among genes that flank AGO2-bound tRNA genes. This effect was shown to be distinct from that of the disruption of DICER, DROSHA, or CTCF. We propose that AGO2 binding to tRNA genes has a novel and important regulatory role in human cells. ChIP-seq for AGO2 was performed from K562 cells using 2 commercially available monoclonal antibodies (mAbs) and 5 replicates. Replicates 1-3 were performed with Millipore 04-642, and replicates 4 and 5 were performed with Abcam 57113. RNA-seq was carried out on 2 replicates of shMock and 2 replicates of shAGO2. Lentiviral vectors GIPZ Lentiviral #RHS4531-EG271611.

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Argonaute 2 binds directly to tRNA genes and promotes gene repression in cis

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