Does looping and clustering in the nucleus regulate gene expression?
There has been considerable interest in the way that chromatin is spatially organised within the cell nucleus and how that may relate to gene expression and its control. New molecular techniques have identified looped chromatin domains at the mammalian beta-globin and the Drosophila hsp70 loci. Looped domains may insulate chromatin from the influence of neighbouring domains, and the bases of loops may also act to concentrate proteins locally within the nucleus. The spatial clustering of sequences from the Drosophila bithorax complex, located in trans, has also been demonstrated. An emerging theme is that bringing DNA and proteins together within a defined sub-region of the nuclear volume facilitates both the activation and the repression of gene expression. Nuclear compartments may also be involved in the post-translational modification of proteins by sumoylation and ubiquitylation.
Chambeyron
Séverine
S
MRC Human Genetics Unit, Crewe Road, Edinburgh EH4 2XU, Scotland, UK.
Bickmore
Wendy A
WA
D000818:Animals; D001665:Binding Sites; D002467:Cell Nucleus / Q000235:genetics* / Q000378:metabolism; D002843:Chromatin / Q000235:genetics* / Q000378:metabolism; D004330:Drosophila / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D005914:Globins / Q000235:genetics; D006801:Humans; D019901:Locus Control Region; D011499:Protein Processing, Post-Translational
D002843:Chromatin; D005914:Globins