Establishment of Polycomb silencing requires a transient interaction between PC and ESC.
Two distinct types of Polycomb complexes have been identified in flies and in vertebrates, one containing ESC and one containing PC. Using LexA fusions, we show that PC and ESC can establish silencing of a reporter gene but that each requires the presence of the other. In early embryonic extracts, we find PC transiently associated with ESC in a complex that includes EZ, PHO, PH, GAGA, and RPD3 but not PSC. In older embryos, PC is found in a complex including PH, PSC, GAGA, and RPD3, whereas ESC is in a separate complex including EZ, PHO, and RPD3.
Poux
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S
Department of Zoology, University of Geneva, CH-1211 Geneva, Switzerland.
Melfi
R
R
Pirrotta
V
V
D000818:Animals; D004330:Drosophila; D029721:Drosophila Proteins; D020868:Gene Silencing; D011495:Histone-Lysine N-Methyltransferase; D019476:Insect Proteins / Q000235:genetics* / Q000378:metabolism; D063150:Polycomb Repressive Complex 1; D063151:Polycomb Repressive Complex 2; D063146:Polycomb-Group Proteins; D011233:Precipitin Tests; D011485:Protein Binding; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism
D029721:Drosophila Proteins; D019476:Insect Proteins; C066770:Pc protein, Drosophila; D063146:Polycomb-Group Proteins; D012097:Repressor Proteins; D011495:Histone-Lysine N-Methyltransferase; D063151:Polycomb Repressive Complex 2; C543389:esc protein, Drosophila; D063150:Polycomb Repressive Complex 1