Histone H3 phosphorylation and cell division

Histone H3 is specifically phosphorylated during both mitosis and meiosis i n patterns that are specifically coordinated in both space and time. Histon e H3 phosphorylation may initiate at different phases of the cell division in different organisms, but metaphase chromosomes are always found to be he avily phosphorylated. Upon exit of mitosis/meiosis a global dephosphorylati on of H3 takes place. Potential candidates for H3 kinases are described and their hypothetical mechanism of action on highly condensed chromatin templ ates is discussed. In addition, a novel hypothesis for the role of histone HS phosphorylation during cell division is proposed. This hypothesis, terme d the 'ready production label' model, explains the results in the literatur e and suggests that phosphorylation of histone H3 is a part of a complex si gnaling mechanism.