Faculty Opinions recommendation of Polycomb group protein complexes exchange rapidly in living Drosophila.

ABSTRACT In Drosophila melanogaster, thePolycomb-group (PcG) andtrithorax-group (trxG) genes have been identified as repressors and activators, respectively, of gene expression. Both groups of genes are required for the stable transmission of gene expression patterns to progeny cells throughout development. Several lines of evidence suggest a functional interaction between the PcG and trxG proteins. For example, genetic evidence indicates that the enhancer of zeste [E(z)] gene can be considered both a PcG and a trxGgene. To better understand the molecular interactions in which the E(z) protein is involved, we performed a two-hybrid screen with Enx1/EZH2, a mammalian homolog of E(z), as the target. We report the identification of the human EED protein, which interacts with Enx1/EZH2. EED is the human homolog ofeed, a murine PcG gene which has extensive homology with the Drosophila PcG gene extra sex combs(esc). Enx1/EZH2 and EED coimmunoprecipitate, indicating that they also interact in vivo. However, Enx1/EZH2 and EED do not coimmunoprecipitate with other human PcG proteins, such as HPC2 and BMI1. Furthermore, unlike HPC2 and BMI1, which colocalize in nuclear domains of U-2 OS osteosarcoma cells, Enx1/EZH2 and EED do not colocalize with HPC2 or BMI1. Our findings indicate that Enx1/EZH2 and EED are members of a class of PcG proteins that is distinct from previously described human PcG proteins.

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Pancreas development and the Polycomb group protein complexes

Mechanisms of Development ◽

10.1016/j.mod.2020.103647 ◽

2020 ◽

Vol 164 ◽

pp. 103647

Author(s):

Niloufer P. Dumasia ◽

Prasad S. Pethe

Keyword(s):

Protein Complexes ◽

Polycomb Group ◽

Pancreas Development ◽

Polycomb Group Protein ◽

Group Protein

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Polycomb group protein complexes exchange rapidly in living Drosophila

Development ◽

10.1242/dev.132.17.4016 ◽

2005 ◽

Vol 132 (17) ◽

pp. 4016-4016

Keyword(s):

Protein Complexes ◽

Polycomb Group ◽

Polycomb Group Protein ◽

Group Protein

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Involvement of the Polycomb-group geneRing1Bin the specification of the anterior-posterior axis in mice

Development ◽

10.1242/dev.129.18.4171 ◽

2002 ◽

Vol 129 (18) ◽

pp. 4171-4183 ◽

Cited By ~ 3

Author(s):

Maki Suzuki ◽

Yoko Mizutani-Koseki ◽

Yu-ichi Fujimura ◽

Hiro Miyagishima ◽

Tomomi Kaneko ◽

...

Keyword(s):

Transcriptional Repression ◽

Hox Genes ◽

Protein Complexes ◽

Mouse Genome Informatics ◽

Axial Skeleton ◽

Polycomb Group ◽

Polycomb Group Protein ◽

Chromosomal Dna ◽

Polycomb Group Genes ◽

Group Protein

The products of the Polycomb group of genes form complexes that maintain the state of transcriptional repression of several genes with relevance to development and in cell proliferation. We have identified Ring1B, the product of the Ring1B gene (Rnf2 – Mouse Genome Informatics), by means of its interaction with the Polycomb group protein Mel18. We describe biochemical and genetic studies directed to understand the biological role of Ring1B. Immunoprecipitation studies indicate that Ring1B form part of protein complexes containing the products of other Polycomb group genes, such as Rae28/Mph1 and M33, and that this complexes associate to chromosomal DNA. We have generated a mouse line bearing a hypomorphic Ring1B allele, which shows posterior homeotic transformations of the axial skeleton and a mild derepression of some Hox genes (Hoxb4, Hoxb6 and Hoxb8) in cells anterior to their normal boundaries of expression in the mesodermal compartment. By contrast, the overexpression of Ring1B in chick embryos results in the repression of Hoxb9 expression in the neural tube. These results, together with the genetic interactions observed in compound Ring1B/Mel18 mutant mice, are consistent with a role for Ring1B in the regulation of Hox gene expression by Polycomb group complexes.

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