Function of the Polycomb protein is conserved in mice and flies

J. Muller; S. Gaunt; P.A. Lawrence

doi:10.1242/dev.121.9.2847

Function of the Polycomb protein is conserved in mice and flies

Development ◽

10.1242/dev.121.9.2847 ◽

1995 ◽

Vol 121 (9) ◽

pp. 2847-2852 ◽

Cited By ~ 13

Author(s):

J. Muller ◽

S. Gaunt ◽

P.A. Lawrence

Keyword(s):

Gene Expression ◽

Molecular Mechanism ◽

Polycomb Group ◽

Polycomb Group Proteins ◽

Cell Fates ◽

Cell Determination ◽

Mouse Homologue ◽

Polycomb Protein ◽

Selector Genes ◽

Transgenic Flies

A key aspect of determination--the acquisition and propagation of cell fates--is the initiation of patterns of selector gene expression and their maintenance in groups of cells as they divide and develop. In Drosophila, in those groups of cells where particular selector genes must remain inactive, it is the Polycomb-Group of genes that keep them silenced. Here we show that M33, a mouse homologue of the Drosophila Polycomb protein, can substitute for Polycomb in transgenic flies. Polycomb protein is thought to join with other Polycomb-Group proteins to build a complex that silences selector genes. Since members of this group of proteins have their homologues in mice, our results suggest that the molecular mechanism of cell determination is widely conserved.

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Molecular characterisation of the Polycomblike gene of Drosophila melanogaster, a trans-acting negative regulator of homeotic gene expression

Development ◽

10.1242/dev.120.9.2629 ◽

1994 ◽

Vol 120 (9) ◽

pp. 2629-2636 ◽

Cited By ~ 19

Author(s):

A. Lonie ◽

R. D'Andrea ◽

R. Paro ◽

R. Saint

Keyword(s):

Gene Expression ◽

Drosophila Melanogaster ◽

Polycomb Group ◽

Negative Regulator ◽

Homeotic Gene ◽

Homeotic Genes ◽

Molecular Characterisation ◽

Polycomb Group Proteins ◽

Polycomb Group Genes ◽

Homeotic Gene Expression

The Polycomblike gene of Drosophila melanogaster, a member of the Polycomb Group of genes, is required for the correct spatial expression of the homeotic genes of the Antennapaedia and Bithorax Complexes. Mutations in Polycomb Group genes result in ectopic homeotic gene expression, indicating that Polycomb Group proteins maintain the transcriptional repression of specific homeotic genes in specific tissues during development. We report here the isolation and molecular characterisation of the Polycomblike gene. The Polycomblike transcript encodes an 857 amino acid protein with no significant homology to other proteins. Antibodies raised against the product of this open reading frame were used to show that the Polycomblike protein is found in all nuclei during embryonic development. Antibody staining also revealed that the Polycomblike protein is found on larval salivary gland polytene chromosomes at about 100 specific loci, the same loci to which the Polycomb and polyhomeotic proteins, two other Polycomb Group proteins, are found. These data add further support for a model in which Polycomb Group proteins form multimeric protein complexes at specific chromosomal loci to repress transcription at those loci.

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The Polycomb group in Caenorhabditis elegans and maternal control of germline development

Development ◽

10.1242/dev.125.13.2469 ◽

1998 ◽

Vol 125 (13) ◽

pp. 2469-2478 ◽

Cited By ~ 7

Author(s):

I. Korf ◽

Y. Fan ◽

S. Strome

Keyword(s):

Gene Expression ◽

Caenorhabditis Elegans ◽

Polycomb Group ◽

Polycomb Group Proteins ◽

Polycomb Group Protein ◽

Maternal Control ◽

Germline Development ◽

C Elegans ◽

Polycomb Group Genes ◽

Group Protein

Four Caenorhabditis elegans genes, mes-2, mes-3, mes-4 and mes-6, are essential for normal proliferation and viability of the germline. Mutations in these genes cause a maternal-effect sterile (i.e. mes) or grandchildless phenotype. We report that the mes-6 gene is in an unusual operon, the second example of this type of operon in C. elegans, and encodes the nematode homolog of Extra sex combs, a WD-40 protein in the Polycomb group in Drosophila. mes-2 encodes another Polycomb group protein (see paper by Holdeman, R., Nehrt, S. and Strome, S. (1998). Development 125, 2457–2467). Consistent with the known role of Polycomb group proteins in regulating gene expression, MES-6 is a nuclear protein. It is enriched in the germline of larvae and adults and is present in all nuclei of early embryos. Molecular epistasis results predict that the MES proteins, like Polycomb group proteins in Drosophila, function as a complex to regulate gene expression. Database searches reveal that there are considerably fewer Polycomb group genes in C. elegans than in Drosophila or vertebrates, and our studies suggest that their primary function is in controlling gene expression in the germline and ensuring the survival and proliferation of that tissue.

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The Xenopus homologue of Down syndrome critical region protein 6 drives dorsoanterior gene expression and embryonic axis formation by antagonising polycomb group proteins

Development ◽

10.1242/dev.098319 ◽

2013 ◽

Vol 140 (24) ◽

pp. 4903-4913 ◽

Cited By ~ 10

Author(s):

H.-Y. Li ◽

R. Grifone ◽

A. Saquet ◽

C. Carron ◽

D.-L. Shi

Keyword(s):

Gene Expression ◽

Down Syndrome ◽

Critical Region ◽

Embryonic Axis ◽

Polycomb Group ◽

Axis Formation ◽

Polycomb Group Proteins

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Circular ANRIL isoforms switch from repressors to activators of p15/CDKN2B expression during RAF1 oncogene-induced senescence

10.1101/2020.04.28.065888 ◽

2020 ◽

Author(s):

Lisa Muniz ◽

Sandra Lazorthes ◽

Maxime Delmas ◽

Julien Ouvrard ◽

Marion Aguirrebengoa ◽

...

Keyword(s):

Gene Expression ◽

Cell Fate ◽

Protein Localization ◽

Polycomb Group ◽

Circular Rnas ◽

Polycomb Proteins ◽

Cycle Arrest ◽

Polycomb Protein ◽

Stable Species ◽

Non Coding Rnas

AbstractLong non-coding RNAs (ncRNAs) are major regulators of gene expression and cell fate. The INK4 locus encodes the tumour suppressor proteins p15INK4b, p16INK4a and p14ARF required for cell cycle arrest and whose expression increases during senescence. ANRIL is a ncRNA antisense to the p15 gene. In proliferative cells, ANRIL prevents senescence by repressing INK4 genes through the recruitment of Polycomb-group proteins. In models of replicative and RASval12 oncogene-induced senescence (OIS), the expression of ANRIL and Polycomb proteins decreases, thus allowing INK4 derepression. Here, we found in a model of RAF1 OIS that ANRIL expression rather increases, due in particular to an increased stability. This led us to search for circular ANRIL isoforms, as circular RNAs are rather stable species. We found that the expression of two circular ANRIL increases in several OIS models (RAF1, MEK1 and BRAF). In proliferative cells, they repress p15 expression, while in RAF1 OIS, they promote full induction of p15, p16 and p14ARF expression. Further analysis of one of these circular ANRIL shows that it interacts with Polycomb proteins and decreases EZH2 Polycomb protein localization and H3K27me3 at the p15 and p16 promoters, respectively. We propose that changes in the ratio between Polycomb proteins and circular ANRIL isoforms allow these isoforms to switch from repressors of p15 gene to activators of all INK4 genes in RAF1 OIS. Our data reveal that regulation of ANRIL expression depends on the senescence inducer and underline the importance of circular ANRIL in the regulation of INK4 gene expression and senescence.

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