Closed chromatin architecture is induced by an RNA duplex targeting the HIV-1 promoter region

@article{citeulike:2875083, abstract = {In some mammalian systems small interfering RNAs (siRNA) targeting homologous sequences in promoter regions of genes induce transcriptional gene silencing (TGS). We have previously reported the induction of TGS by a siRNA (prom-A siRNA) targeting the tandem NF-B binding motifs within the HIV-1 promoter region. Here we report that induction of TGS by prom-A siRNA is accompanied by immediate and sustained local recruitment of Argonaute-1 (Ago1), histone deacetylase-1 (HDAC1), and induction of dimethylation of histone 3 at lysine 9 (H3K9me2), processes known to be associated with transcriptional silencing. Elevated levels of H3K9me2 and HDAC1 spread upstream of the target sequence and elevated H3K9me2 levels also spread downstream into the coding region. Moreover, this siRNA induces an immediate change in DNA accessibility to restriction enzyme digestion in the region of the transcription initiation site of the HIV-1. This change in accessibility is due to the relocation of a nucleosome known to be associated with this region of the integrated pro-virus. Although there is a theoretical possibility that the observed viral suppression could be mediated by PTGS mechanism with this siRNA acting at the 3'LTR of the virus, we demonstrate that this siRNA, and three other U3 targeted siRNAs, are inefficient inducers of PTGS. These data strongly suggest that siRNA targeting the promoter region acts predominantly at a site within the 5'LTR of HIV to induce transcriptional silencing and alterations to chromatin structure of the HIV promoter region that extend well beyond the immediate siRNA target site. These induced changes are consistent with those described in latent HIV-1 infection. 10.1074/jbc.M709651200}, author = {Suzuki, Kazuo and Juelich, Torsten and Lim, Heidi and Ishida, Takaomi and Watanebe, Toshiki and Cooper, David A. and Rao, Sudha and Kelleher, Anthony D. }, citeulike-article-id = {2875083}, doi = {10.1074/jbc.M709651200}, journal = {J. Biol. Chem.}, keywords = {techniques}, month = {June}, pages = {M709651200+}, posted-at = {2008-06-09 10:32:48}, priority = {2}, title = {Closed chromatin architecture is induced by an RNA duplex targeting the HIV-1 promoter region}, url = {http://dx.doi.org/10.1074/jbc.M709651200}, year = {2008} }

TY - JOUR ID - citeulike:2875083 L3 - citeulike-article-id:2875083 TI - Closed chromatin architecture is induced by an RNA duplex targeting the HIV-1 promoter region JF - J. Biol. Chem. SP - M709651200 N2 - In some mammalian systems small interfering RNAs (siRNA) targeting homologous sequences in promoter regions of genes induce transcriptional gene silencing (TGS). We have previously reported the induction of TGS by a siRNA (prom-A siRNA) targeting the tandem NF-B binding motifs within the HIV-1 promoter region. Here we report that induction of TGS by prom-A siRNA is accompanied by immediate and sustained local recruitment of Argonaute-1 (Ago1), histone deacetylase-1 (HDAC1), and induction of dimethylation of histone 3 at lysine 9 (H3K9me2), processes known to be associated with transcriptional silencing. Elevated levels of H3K9me2 and HDAC1 spread upstream of the target sequence and elevated H3K9me2 levels also spread downstream into the coding region. Moreover, this siRNA induces an immediate change in DNA accessibility to restriction enzyme digestion in the region of the transcription initiation site of the HIV-1. This change in accessibility is due to the relocation of a nucleosome known to be associated with this region of the integrated pro-virus. Although there is a theoretical possibility that the observed viral suppression could be mediated by PTGS mechanism with this siRNA acting at the 3'LTR of the virus, we demonstrate that this siRNA, and three other U3 targeted siRNAs, are inefficient inducers of PTGS. These data strongly suggest that siRNA targeting the promoter region acts predominantly at a site within the 5'LTR of HIV to induce transcriptional silencing and alterations to chromatin structure of the HIV promoter region that extend well beyond the immediate siRNA target site. These induced changes are consistent with those described in latent HIV-1 infection. 10.1074/jbc.M709651200 KW - techniques AU - Suzuki, Kazuo AU - Juelich, Torsten AU - Lim, Heidi AU - Ishida, Takaomi AU - Watanebe, Toshiki AU - Cooper, David AU - Rao, Sudha AU - Kelleher, Anthony PY - 2008/06/02/ UR - http://dx.doi.org/10.1074/jbc.M709651200 ER -