Repression of germline RNAi pathways in somatic cells by retinoblastoma pathway chromatin complexes.

The retinoblastoma (Rb) tumor suppressor acts with a number of chromatin cofactors in a wide range of species to suppress cell proliferation. The Caenorhabditis elegans retinoblastoma gene and many of these cofactors, called synMuv B genes, were identified in genetic screens for cell lineage defects...

Full description

Bibliographic Details
Main Authors: Xiaoyun Wu, Zhen Shi, Mingxue Cui, Min Han, Gary Ruvkun
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2012-01-01
Series:PLoS Genetics
Online Access:http://europepmc.org/articles/PMC3297578?pdf=render
_version_ 1818419054675755008
author Xiaoyun Wu
Zhen Shi
Mingxue Cui
Min Han
Gary Ruvkun
author_facet Xiaoyun Wu
Zhen Shi
Mingxue Cui
Min Han
Gary Ruvkun
author_sort Xiaoyun Wu
collection DOAJ
description The retinoblastoma (Rb) tumor suppressor acts with a number of chromatin cofactors in a wide range of species to suppress cell proliferation. The Caenorhabditis elegans retinoblastoma gene and many of these cofactors, called synMuv B genes, were identified in genetic screens for cell lineage defects caused by growth factor misexpression. Mutations in many synMuv B genes, including lin-35/Rb, also cause somatic misexpression of the germline RNA processing P granules and enhanced RNAi. We show here that multiple small RNA components, including a set of germline-specific Argonaute genes, are misexpressed in the soma of many synMuv B mutant animals, revealing one node for enhanced RNAi. Distinct classes of synMuv B mutants differ in the subcellular architecture of their misexpressed P granules, their profile of misexpressed small RNA and P granule genes, as well as their enhancement of RNAi and the related silencing of transgenes. These differences define three classes of synMuv B genes, representing three chromatin complexes: a LIN-35/Rb-containing DRM core complex, a SUMO-recruited Mec complex, and a synMuv B heterochromatin complex, suggesting that intersecting chromatin pathways regulate the repression of small RNA and P granule genes in the soma and the potency of RNAi. Consistent with this, the DRM complex and the synMuv B heterochromatin complex were genetically additive and displayed distinct antagonistic interactions with the MES-4 histone methyltransferase and the MRG-1 chromodomain protein, two germline chromatin regulators required for the synMuv phenotype and the somatic misexpression of P granule components. Thus intersecting synMuv B chromatin pathways conspire with synMuv B suppressor chromatin factors to regulate the expression of small RNA pathway genes, which enables heightened RNAi response. Regulation of small RNA pathway genes by human retinoblastoma may also underlie its role as a tumor suppressor gene.
first_indexed 2024-12-14T12:32:28Z
format Article
id doaj.art-0fbc5c08f3fd4147b83330a5a7fdd96a
institution Directory Open Access Journal
issn 1553-7390
1553-7404
language English
last_indexed 2024-12-14T12:32:28Z
publishDate 2012-01-01
publisher Public Library of Science (PLoS)
record_format Article
series PLoS Genetics
spelling doaj.art-0fbc5c08f3fd4147b83330a5a7fdd96a2022-12-21T23:01:08ZengPublic Library of Science (PLoS)PLoS Genetics1553-73901553-74042012-01-0183e100254210.1371/journal.pgen.1002542Repression of germline RNAi pathways in somatic cells by retinoblastoma pathway chromatin complexes.Xiaoyun WuZhen ShiMingxue CuiMin HanGary RuvkunThe retinoblastoma (Rb) tumor suppressor acts with a number of chromatin cofactors in a wide range of species to suppress cell proliferation. The Caenorhabditis elegans retinoblastoma gene and many of these cofactors, called synMuv B genes, were identified in genetic screens for cell lineage defects caused by growth factor misexpression. Mutations in many synMuv B genes, including lin-35/Rb, also cause somatic misexpression of the germline RNA processing P granules and enhanced RNAi. We show here that multiple small RNA components, including a set of germline-specific Argonaute genes, are misexpressed in the soma of many synMuv B mutant animals, revealing one node for enhanced RNAi. Distinct classes of synMuv B mutants differ in the subcellular architecture of their misexpressed P granules, their profile of misexpressed small RNA and P granule genes, as well as their enhancement of RNAi and the related silencing of transgenes. These differences define three classes of synMuv B genes, representing three chromatin complexes: a LIN-35/Rb-containing DRM core complex, a SUMO-recruited Mec complex, and a synMuv B heterochromatin complex, suggesting that intersecting chromatin pathways regulate the repression of small RNA and P granule genes in the soma and the potency of RNAi. Consistent with this, the DRM complex and the synMuv B heterochromatin complex were genetically additive and displayed distinct antagonistic interactions with the MES-4 histone methyltransferase and the MRG-1 chromodomain protein, two germline chromatin regulators required for the synMuv phenotype and the somatic misexpression of P granule components. Thus intersecting synMuv B chromatin pathways conspire with synMuv B suppressor chromatin factors to regulate the expression of small RNA pathway genes, which enables heightened RNAi response. Regulation of small RNA pathway genes by human retinoblastoma may also underlie its role as a tumor suppressor gene.http://europepmc.org/articles/PMC3297578?pdf=render
spellingShingle Xiaoyun Wu
Zhen Shi
Mingxue Cui
Min Han
Gary Ruvkun
Repression of germline RNAi pathways in somatic cells by retinoblastoma pathway chromatin complexes.
PLoS Genetics
title Repression of germline RNAi pathways in somatic cells by retinoblastoma pathway chromatin complexes.
title_full Repression of germline RNAi pathways in somatic cells by retinoblastoma pathway chromatin complexes.
title_fullStr Repression of germline RNAi pathways in somatic cells by retinoblastoma pathway chromatin complexes.
title_full_unstemmed Repression of germline RNAi pathways in somatic cells by retinoblastoma pathway chromatin complexes.
title_short Repression of germline RNAi pathways in somatic cells by retinoblastoma pathway chromatin complexes.
title_sort repression of germline rnai pathways in somatic cells by retinoblastoma pathway chromatin complexes
url http://europepmc.org/articles/PMC3297578?pdf=render
work_keys_str_mv AT xiaoyunwu repressionofgermlinernaipathwaysinsomaticcellsbyretinoblastomapathwaychromatincomplexes
AT zhenshi repressionofgermlinernaipathwaysinsomaticcellsbyretinoblastomapathwaychromatincomplexes
AT mingxuecui repressionofgermlinernaipathwaysinsomaticcellsbyretinoblastomapathwaychromatincomplexes
AT minhan repressionofgermlinernaipathwaysinsomaticcellsbyretinoblastomapathwaychromatincomplexes
AT garyruvkun repressionofgermlinernaipathwaysinsomaticcellsbyretinoblastomapathwaychromatincomplexes