Histone Methyltransferase Activity of a Drosophila Polycomb Group Repressor Complex

Abstract

Polycomb group (PcG) proteins maintain transcriptional repression during development, likely by creating repressive chromatin states. The Extra Sex Combs (ESC) and Enhancer of Zeste [E(Z)] proteins are partners in an essential PcG complex, but its full composition and biochemical activities are not known. A SET domain in E(Z) suggests this complex might methylate histones. We purified an ESC-E(Z) complex from Drosophila embryos and found four major subunits: ESC, E(Z), NURF-55, and the PcG repressor, SU(Z)12. A recombinant complex reconstituted from these four subunits methylates lysine-27 of histone H3. Mutations in the E(Z) SET domain disrupt methyltransferase activity in vitro and HOX gene repression in vivo. These results identify E(Z) as a PcG protein with enzymatic activity and implicate histone methylation in PcG-mediated silencing.

Interrogating the Function of Metazoan Histones using Engineered Gene Clusters

“…Clones of E(z) mutant wing imaginal disc cells show ectopic expression of Ubx in the wing pouch near the dorsal-ventral boundary (Figure 6A), consistent with previous findings (Muller et al, 2002). Clones of cells lacking Pc function also ectopically express Ubx in the same spatial pattern as E(z) mutant clones (Figure 6B).…”

Interrogating the Function of Metazoan Histones using Engineered Gene Clusters

“…Clones of E(z) mutant wing imaginal disc cells show ectopic expression of Ubx in the wing pouch near the dorsal-ventral boundary (Figure 6A), consistent with previous findings (Muller et al, 2002). Clones of cells lacking Pc function also ectopically express Ubx in the same spatial pattern as E(z) mutant clones (Figure 6B).…”

Molecular analysis of PRC2 recruitment to DNA in chromatin and its inhibition by RNA

“…1d ). We also observed automethylation of the EZH2 subunit, as has been previously reported by other groups 21 , 22 (dashed blue box, Fig. 1d ).…”

The Drosophila methyl-DNA binding protein MBD2/3 interacts with the NuRD complex via p55 and MI-2

“…1). This is in agreement with the fact that both RPD3 and p55 are also components of other chromatin related complexes [25,26]. …”

Interrogating the Function of Metazoan Histones using Engineered Gene Clusters

“…Clones of E(z) mutant wing imaginal disc cells show ectopic expression of Ubx in the wing pouch near the dorsal-ventral boundary (Figure 6A), consistent with previous findings (Muller et al, 2002). Clones of cells lacking Pc function also ectopically express Ubx in the same spatial pattern as E(z) mutant clones (Figure 6B).…”

Molecular analysis of PRC2 recruitment to DNA in chromatin and its inhibition by RNA

“…1d ). We also observed automethylation of the EZH2 subunit, as has been previously reported by other groups 21 , 22 (dashed blue box, Fig. 1d ).…”

The Drosophila methyl-DNA binding protein MBD2/3 interacts with the NuRD complex via p55 and MI-2

“…1). This is in agreement with the fact that both RPD3 and p55 are also components of other chromatin related complexes [25,26]. …”

Interrogating the Function of Metazoan Histones using Engineered Gene Clusters

“…Clones of E(z) mutant wing imaginal disc cells show ectopic expression of Ubx in the wing pouch near the dorsal-ventral boundary (Figure 6A), consistent with previous findings (Muller et al, 2002). Clones of cells lacking Pc function also ectopically express Ubx in the same spatial pattern as E(z) mutant clones (Figure 6B).…”

Molecular analysis of PRC2 recruitment to DNA in chromatin and its inhibition by RNA

“…1d ). We also observed automethylation of the EZH2 subunit, as has been previously reported by other groups 21 , 22 (dashed blue box, Fig. 1d ).…”

The Drosophila methyl-DNA binding protein MBD2/3 interacts with the NuRD complex via p55 and MI-2

“…1). This is in agreement with the fact that both RPD3 and p55 are also components of other chromatin related complexes [25,26]. …”