The end adjusts the means: Heterochromatin remodelling during terminal cell differentiation
- 205 Downloads
All cells that constitute mature tissues in an eukaryotic organism undergo a multistep process of cell differentiation. At the terminal stage of this process, cells either cease to proliferate forever or rest for a very long period of time. During terminal differentiation, most of the genes that are required for cell ‘housekeeping’ functions, such as proto-oncogenes and other cell-cycle and cell proliferation genes, become stably repressed. At the same time, nuclear chromatin undergoes dramatic morphological and structural changes at the higher-order levels of chromatin organization. These changes involve both constitutively inactive chromosomal regions (constitutive heterochromatin) and the formerly active genes that become silenced and structurally modified to form facultative heterochromatin. Here we approach terminal cell differentiation as a unique system that allows us to combine biochemical, ultrastructural and molecular genetic techniques to study the relationship between the hierarchy of chromatin higher-order structures in the nucleus and its function(s) in dynamic packing of genetic material in a form that remains amenable to regulation of gene activity and other DNA-dependent cellular processes.
Key wordscell differentiation chromatin higher-order structure heterochromatin histone nucleosome
Unable to display preview. Download preview PDF.
- Fischle W, Tseng BS, Dormann HL et al (2005) Regulation of HP1-chromatin binding by histone H3 methylation and phosphorylation. Nature, Epub 12 Oct 2005.Google Scholar
- Heitz, E (1928) Das Heterochromatin der Moose. I Jb Wisensch Bot 69: 762–818.Google Scholar
- Hirota T, Lipp JJ, Toh BH, Peters JM (2005) Histone H3 serine 10 phosphorylation by Aurora B causes HP1 dissociation from heterochromatin. Nature, Epub 12 Oct 2005.Google Scholar
- McBryant SJ, Adams VH, Hansen JC (2006) Chromatin architectural proteins. Chromosome Res 14: 39–51. Google Scholar
- Terranova R, Sauer S, Merkenschlager M, Fisher AG (2005) The reorganisation of constitutive heterochromatin in differentiating muscle requires HDAC activity. Exp Cell Res 20: 20.Google Scholar