Figure 2

Regulation of mitotic events by fungal NIMA-related kinases. The Aspergillus NIMA kinase and fission yeast Fin1 kinase regulate multiple events during mitotic progression. Both proteins contribute to the timing of mitotic entry through controlling the localization and/or activation of the Cdc2/cyclin B kinase (Plo1 is an upstream activator of Cdc2/cyclin B). However, the relative importance of NIMA and Fin1 in this event appears to vary as nimA mutants block mitotic entry, whereas fin1 mutants only delay mitotic entry. Both proteins are also strongly implicated in regulation of mitotic spindle formation. In addition, NIMA promotes chromatin condensation, while Fin1 is involved in the pathway regulating cytokinesis. Unfortunately, the mechanisms by which these kinases operate remain poorly understand primarily because few direct substrates (indicated in red) have been identified.