RNAi-Dependent and -Independent RNA Turnover Mechanisms Contribute to Heterochromatic Gene Silencing

@article{citeulike:1418191, abstract = {Summary In fission yeast, the RNAi pathway is required for heterochromatin-dependent silencing of transgene insertions at centromeric repeats and acts together with other pathways to silence transgenes at the silent mating-type locus. Here, we show that transgene transcripts at centromeric repeats are processed into siRNAs and are therefore direct targets of RNAi. Furthermore, we show that Cid14, a member of the Trf4/5 family of poly(A) polymerases, has poly(A) polymerase activity that is required for heterochromatic gene silencing. Surprisingly, while siRNA levels in cid14[Delta] cells are dramatically reduced, the structural integrity of heterochromatin appears to be preserved. Cid14 resides in a complex similar to the TRAMP complex found in budding yeast, which is part of a nuclear surveillance mechanism that degrades aberrant transcripts. Our findings indicate that polyadenylation by a TRAMP-like complex contributes to robust silencing of heterochromatic genes in fission yeast via the recruitment of the exosome and/or the RNAi machinery.}, author = {Buhler, Marc and Haas, Wilhelm and Gygi, Steven P. and Moazed, Danesh }, citeulike-article-id = {1418191}, journal = {Cell}, keywords = {chromatin, epigenetics, rnai}, month = {May}, number = {4}, pages = {707--721}, posted-at = {2007-06-29 17:00:20}, priority = {2}, title = {RNAi-Dependent and -Independent RNA Turnover Mechanisms Contribute to Heterochromatic Gene Silencing}, url = {http://www.sciencedirect.com/science/article/B6WSN-4NRTWPR-G/2/1eb0f3eb8eea7b272c48738343abfe4c}, volume = {129}, year = {2007} }

TY - JOUR ID - citeulike:1418191 L3 - citeulike-article-id:1418191 TI - RNAi-Dependent and -Independent RNA Turnover Mechanisms Contribute to Heterochromatic Gene Silencing JF - Cell VL - 129 IS - 4 SP - 707 EP - 721 N2 - Summary In fission yeast, the RNAi pathway is required for heterochromatin-dependent silencing of transgene insertions at centromeric repeats and acts together with other pathways to silence transgenes at the silent mating-type locus. Here, we show that transgene transcripts at centromeric repeats are processed into siRNAs and are therefore direct targets of RNAi. Furthermore, we show that Cid14, a member of the Trf4/5 family of poly(A) polymerases, has poly(A) polymerase activity that is required for heterochromatic gene silencing. Surprisingly, while siRNA levels in cid14[Delta] cells are dramatically reduced, the structural integrity of heterochromatin appears to be preserved. Cid14 resides in a complex similar to the TRAMP complex found in budding yeast, which is part of a nuclear surveillance mechanism that degrades aberrant transcripts. Our findings indicate that polyadenylation by a TRAMP-like complex contributes to robust silencing of heterochromatic genes in fission yeast via the recruitment of the exosome and/or the RNAi machinery. KW - chromatin KW - epigenetics KW - rnai AU - Buhler, Marc AU - Haas, Wilhelm AU - Gygi, Steven AU - Moazed, Danesh PY - 2007/05/18/ UR - http://www.sciencedirect.com/science/article/B6WSN-4NRTWPR-G/2/1eb0f3eb8eea7b272c48738343abfe4c ER -