ABSTRACT
A schematic representation of the mitotic cell cycle is shown in this chapter. Phosphorylation of histone H1 increases its ability to dissociate from the chromatin fiber. In the context of cell cycle progression, it is known that tethering of Cdc45-a protein associated with the transition from G1 to S phase-to a chromosomal locus promotes large-scale chromatin decondensation. When a cell divides, chromosomes need to reorganize into compact rod-shaped bodies to permit the segregation of their replicated sister chromatids to opposite spindle poles. A fascinating aspect of the mitotic cell cycle is that the pattern of histone modifications present in the genome of specific cell types is identical (for all practical purposes) before and after mitosis. Such epigenetic “memory” of the cell’s transcriptional profile is currently a very active area of investigation.
