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Distinct Cytoplasmic and Nuclear Fractions of Drosophila Heterochromatin Protein 1: Their Phosphorylation Levels and Associations with Origin Recognition Complex Proteins
The distinct structural properties of heterochromatin accommodate a diverse group of vital chromosome functions, yet we have only rudimentary molecular details of its structure. A powerful tool in the analyses of its structure in Drosophila has been a group of mutations that reverse the repressive e...
Autores principales: | , , , , , |
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Formato: | Texto |
Lenguaje: | English |
Publicado: |
The Rockefeller University Press
1998
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2133057/ https://www.ncbi.nlm.nih.gov/pubmed/9679132 |
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author | Huang, Da Wei Fanti, Laura Pak, Daniel T.S. Botchan, Michael R. Pimpinelli, Sergio Kellum, Rebecca |
author_facet | Huang, Da Wei Fanti, Laura Pak, Daniel T.S. Botchan, Michael R. Pimpinelli, Sergio Kellum, Rebecca |
author_sort | Huang, Da Wei |
collection | PubMed |
description | The distinct structural properties of heterochromatin accommodate a diverse group of vital chromosome functions, yet we have only rudimentary molecular details of its structure. A powerful tool in the analyses of its structure in Drosophila has been a group of mutations that reverse the repressive effect of heterochromatin on the expression of a gene placed next to it ectopically. Several genes from this group are known to encode proteins enriched in heterochromatin. The best characterized of these is the heterochromatin-associated protein, HP1. HP1 has no known DNA-binding activity, hence its incorporation into heterochromatin is likely to be dependent upon other proteins. To examine HP1 interacting proteins, we isolated three distinct oligomeric species of HP1 from the cytoplasm of early Drosophila embryos and analyzed their compositions. The two larger oligomers share two properties with the fraction of HP1 that is most tightly associated with the chromatin of interphase nuclei: an underphosphorylated HP1 isoform profile and an association with subunits of the origin recognition complex (ORC). We also found that HP1 localization into heterochromatin is disrupted in mutants for the ORC2 subunit. These findings support a role for the ORC-containing oligomers in localizing HP1 into Drosophila heterochromatin that is strikingly similar to the role of ORC in recruiting the Sir1 protein to silencing nucleation sites in Saccharomyces cerevisiae. |
format | Text |
id | pubmed-2133057 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 1998 |
publisher | The Rockefeller University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-21330572008-05-01 Distinct Cytoplasmic and Nuclear Fractions of Drosophila Heterochromatin Protein 1: Their Phosphorylation Levels and Associations with Origin Recognition Complex Proteins Huang, Da Wei Fanti, Laura Pak, Daniel T.S. Botchan, Michael R. Pimpinelli, Sergio Kellum, Rebecca J Cell Biol Articles The distinct structural properties of heterochromatin accommodate a diverse group of vital chromosome functions, yet we have only rudimentary molecular details of its structure. A powerful tool in the analyses of its structure in Drosophila has been a group of mutations that reverse the repressive effect of heterochromatin on the expression of a gene placed next to it ectopically. Several genes from this group are known to encode proteins enriched in heterochromatin. The best characterized of these is the heterochromatin-associated protein, HP1. HP1 has no known DNA-binding activity, hence its incorporation into heterochromatin is likely to be dependent upon other proteins. To examine HP1 interacting proteins, we isolated three distinct oligomeric species of HP1 from the cytoplasm of early Drosophila embryos and analyzed their compositions. The two larger oligomers share two properties with the fraction of HP1 that is most tightly associated with the chromatin of interphase nuclei: an underphosphorylated HP1 isoform profile and an association with subunits of the origin recognition complex (ORC). We also found that HP1 localization into heterochromatin is disrupted in mutants for the ORC2 subunit. These findings support a role for the ORC-containing oligomers in localizing HP1 into Drosophila heterochromatin that is strikingly similar to the role of ORC in recruiting the Sir1 protein to silencing nucleation sites in Saccharomyces cerevisiae. The Rockefeller University Press 1998-07-27 /pmc/articles/PMC2133057/ /pubmed/9679132 Text en This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/). |
spellingShingle | Articles Huang, Da Wei Fanti, Laura Pak, Daniel T.S. Botchan, Michael R. Pimpinelli, Sergio Kellum, Rebecca Distinct Cytoplasmic and Nuclear Fractions of Drosophila Heterochromatin Protein 1: Their Phosphorylation Levels and Associations with Origin Recognition Complex Proteins |
title | Distinct Cytoplasmic and Nuclear Fractions of Drosophila Heterochromatin Protein 1: Their Phosphorylation Levels and Associations with Origin Recognition Complex Proteins |
title_full | Distinct Cytoplasmic and Nuclear Fractions of Drosophila Heterochromatin Protein 1: Their Phosphorylation Levels and Associations with Origin Recognition Complex Proteins |
title_fullStr | Distinct Cytoplasmic and Nuclear Fractions of Drosophila Heterochromatin Protein 1: Their Phosphorylation Levels and Associations with Origin Recognition Complex Proteins |
title_full_unstemmed | Distinct Cytoplasmic and Nuclear Fractions of Drosophila Heterochromatin Protein 1: Their Phosphorylation Levels and Associations with Origin Recognition Complex Proteins |
title_short | Distinct Cytoplasmic and Nuclear Fractions of Drosophila Heterochromatin Protein 1: Their Phosphorylation Levels and Associations with Origin Recognition Complex Proteins |
title_sort | distinct cytoplasmic and nuclear fractions of drosophila heterochromatin protein 1: their phosphorylation levels and associations with origin recognition complex proteins |
topic | Articles |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2133057/ https://www.ncbi.nlm.nih.gov/pubmed/9679132 |
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