In:
eLife, eLife Sciences Publications, Ltd, Vol. 5 ( 2016-11-11)
Abstract:
Inside plant, fungi and animal cells, DNA wraps around disc-shaped histone proteins to form structures called nucleosomes. Chains of nucleosomes, each with a small stretch of DNA, help to package meters of genetic material into a compact form called chromatin in the cell’s nucleus. Changes to how chromatin is organized can affect how genes switch on and off. Critically, this allows cells to respond to changes in their environment and to develop into the many cell types required to build animals ranging from worms to humans. For example, specialized groups of proteins that bind to nucleosomes, spread along specific sites of chromatin and can change its structure into an inaccessible form called heterochromatin thereby switching off genes. Proteins that bind to specific nucleosomes control the spreading, gene activity, and even memory properties of heterochromatin. However, it is not clear how these proteins spread from their original binding point on the chromatin to other nucleosomes. Now, Behrouzi, Lu et al. show how heterochromatin spreads to form large, stable structures in budding yeast. Their experiments reveal that heterochromatin proteins attach to sites on neighbouring nucleosomes, forming bridges between them. These findings conflict a long-held view as they show that pairs of nucleosomes, rather than individual nucleosomes, are the natural binding partners for heterochromatin proteins. Also, because these proteins cannot bridge from one side of a nucleosome to the other, they are unlikely to form a continuous chain across multiple nucleosomes on the chromatin. Instead, Behrouzi, Lu et al. observed that a series of short bridges between nucleosomes helps heterochromatin to spread. To fully understand why bridging only happens between separate nucleosomes, the atomic structure of heterochromatin proteins bound to pairs of nucleosomes needs to be determined. In addition, it will be essential to develop more experimental methods to study the spreading of heterochromatin inside cells.
Type of Medium:
Online Resource
ISSN:
2050-084X
DOI:
10.7554/eLife.17556.001
DOI:
10.7554/eLife.17556.002
DOI:
10.7554/eLife.17556.003
DOI:
10.7554/eLife.17556.004
DOI:
10.7554/eLife.17556.005
DOI:
10.7554/eLife.17556.006
DOI:
10.7554/eLife.17556.007
DOI:
10.7554/eLife.17556.008
DOI:
10.7554/eLife.17556.009
DOI:
10.7554/eLife.17556.010
DOI:
10.7554/eLife.17556.011
DOI:
10.7554/eLife.17556.012
DOI:
10.7554/eLife.17556.013
DOI:
10.7554/eLife.17556.014
DOI:
10.7554/eLife.17556.015
DOI:
10.7554/eLife.17556.016
DOI:
10.7554/eLife.17556.017
DOI:
10.7554/eLife.17556.018
DOI:
10.7554/eLife.17556.019
DOI:
10.7554/eLife.17556.020
DOI:
10.7554/eLife.17556.021
DOI:
10.7554/eLife.17556.022
DOI:
10.7554/eLife.17556.025
DOI:
10.7554/eLife.17556.026
Language:
English
Publisher:
eLife Sciences Publications, Ltd
Publication Date:
2016
detail.hit.zdb_id:
2687154-3
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