TY - JOUR
T1 - A Barrier-only boundary element delimits the formation of facultative heterochromatin in Drosophila melanogaster and vertebrates
AU - Lin, Nianwei
AU - Li, Xingguo
AU - Cui, Kairong
AU - Chepelev, Iouri
AU - Tie, Feng
AU - Liu, Bo
AU - Li, Guangyao
AU - Harte, Peter
AU - Zhao, Keji
AU - Huang, Suming
AU - Zhou, Lei
PY - 2011/7
Y1 - 2011/7
N2 - Formation of facultative heterochromatin at specific genomic loci is fundamentally important in defining cellular properties such as differentiation potential and responsiveness to developmental, physiological, and environmental stimuli. By the nature of their formation, heterochromatin and repressive histone marks propagate until the chain reaction is broken. While certain active promoters can block propagation of heterochromatin, there are also specialized DNA elements, referred to as chromatin barriers, that serve to demarcate the boundary of facultative heterochromatin formation. In this study, we identified a chromatin barrier that specifically limits the formation of repressive chromatin to a distal enhancer region so that repressive histone modifications cannot reach the promoter and promoter-proximal enhancer regions of reaper. Unlike all of the known boundary elements identified for Drosophila melanogaster, this IRER (irradiationresponsive enhancer region) left barrier (ILB) does not exhibit enhancer-blocking activity. Not only has the ILB been conserved in different Drosophila species, it can also function as an effective chromatin barrier in vertebrate cells. This suggests that the mechanism by which it functions to spatially restrict the formation of repressive chromatin marked by trimethylated H3K27 has also been conserved widely during evolution.
AB - Formation of facultative heterochromatin at specific genomic loci is fundamentally important in defining cellular properties such as differentiation potential and responsiveness to developmental, physiological, and environmental stimuli. By the nature of their formation, heterochromatin and repressive histone marks propagate until the chain reaction is broken. While certain active promoters can block propagation of heterochromatin, there are also specialized DNA elements, referred to as chromatin barriers, that serve to demarcate the boundary of facultative heterochromatin formation. In this study, we identified a chromatin barrier that specifically limits the formation of repressive chromatin to a distal enhancer region so that repressive histone modifications cannot reach the promoter and promoter-proximal enhancer regions of reaper. Unlike all of the known boundary elements identified for Drosophila melanogaster, this IRER (irradiationresponsive enhancer region) left barrier (ILB) does not exhibit enhancer-blocking activity. Not only has the ILB been conserved in different Drosophila species, it can also function as an effective chromatin barrier in vertebrate cells. This suggests that the mechanism by which it functions to spatially restrict the formation of repressive chromatin marked by trimethylated H3K27 has also been conserved widely during evolution.
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U2 - 10.1128/MCB.05165-11
DO - 10.1128/MCB.05165-11
M3 - Article
C2 - 21518956
AN - SCOPUS:79959474485
VL - 31
SP - 2729
EP - 2741
JO - Molecular and Cellular Biology
JF - Molecular and Cellular Biology
SN - 0270-7306
IS - 13
ER -