title: Subunit contributions to histone methyltransferase activities of fly and worm polycomb group complexes.
abstract: The ESC-E(Z) complex of Drosophila melanogaster Polycomb group (PcG) repressors is a histone H3 methyltransferase (HMTase). This complex silences fly Hox genes, and related HMTases control germ line development in worms, flowering in plants, and X inactivation in mammals. The fly complex contains a catalytic SET domain subunit, E(Z), plus three noncatalytic subunits, SU(Z)12, ESC, and NURF-55. The four-subunit complex is >1,000-fold more active than E(Z) alone. Here we show that ESC and SU(Z)12 play key roles in potentiating E(Z) HMTase activity. We also show that loss of ESC disrupts global methylation of histone H3-lysine 27 in fly embryos. Subunit mutations identify domains required for catalytic activity and/or binding to specific partners. We describe missense mutations in surface loops of ESC, in the CXC domain of E(Z), and in the conserved VEFS domain of SU(Z)12, which each disrupt HMTase activity but preserve complex assembly. Thus, the E(Z) SET domain requires multiple partner inputs to produce active HMTase. We also find that a recombinant worm complex containing the E(Z) homolog, MES-2, has robust HMTase activity, which depends upon both MES-6, an ESC homolog, and MES-3, a pioneer protein. Thus, although the fly and mammalian PcG complexes absolutely require SU(Z)12, the worm complex generates HMTase activity from a distinct partner set.
authors.affiliation: Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, 55455, USA.
authors.forename: Carrie S
authors.initials: CS
authors.lastname: Ketel
authors.forename: Erica F
authors.initials: EF
authors.lastname: Andersen
authors.forename: Marcus L
authors.initials: ML
authors.lastname: Vargas
authors.forename: Jinkyo
authors.initials: J
authors.lastname: Suh
authors.forename: Susan
authors.initials: S
authors.lastname: Strome
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Simon
mesh_terms: D000818:Animals; D016367:Baculoviridae / Q000378:metabolism; D015153:Blotting, Western; D017173:Caenorhabditis elegans; D020134:Catalytic Domain; D002843:Chromatin / Q000737:chemistry; D002868:Chromosomal Proteins, Non-Histone / Q000737:chemistry; D019175:DNA Methylation; D004252:DNA Mutational Analysis; D004305:Dose-Response Relationship, Drug; D029721:Drosophila Proteins / Q000737:chemistry / Q000502:physiology*; D004331:Drosophila melanogaster; D000076983:Histone Methyltransferases; D011495:Histone-Lysine N-Methyltransferase / Q000737:chemistry* / Q000378:metabolism; D006657:Histones / Q000737:chemistry; D006801:Humans; D008239:Lysine / Q000737:chemistry; D046911:Macromolecular Substances / Q000737:chemistry; D008745:Methylation; D008954:Models, Biological; D018832:Molecular Chaperones / Q000737:chemistry; D046912:Multiprotein Complexes / Q000737:chemistry; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D020125:Mutation, Missense; D063150:Polycomb Repressive Complex 1; D063151:Polycomb Repressive Complex 2; D011485:Protein Binding; D011496:Protein Methyltransferases; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000737:chemistry; D011994:Recombinant Proteins / Q000737:chemistry; D012097:Repressor Proteins; D056505:Retinoblastoma-Binding Protein 4; D016335:Zinc Fingers
chemical_list: C110251:Caf1-55 protein, Drosophila; D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D029721:Drosophila Proteins; D006657:Histones; D046911:Macromolecular Substances; D018832:Molecular Chaperones; D046912:Multiprotein Complexes; C066770:Pc protein, Drosophila; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D012097:Repressor Proteins; D056505:Retinoblastoma-Binding Protein 4; C543390:Su(z)12 protein, Drosophila; D000076983:Histone Methyltransferases; D011496:Protein Methyltransferases; D011495:Histone-Lysine N-Methyltransferase; D063151:Polycomb Repressive Complex 2; C543389:esc protein, Drosophila; D063150:Polycomb Repressive Complex 1; D008239:Lysine