The Aspergillus nidulans cyclin PclA accumulates in the nucleus and interacts with the central cell cycle regulator NimX(Cdc2).

The filamentous fungus Aspergillus nidulans reproduces asexually through conidiospores, which are continuously generated at morphologically differentiated structures, the conidiophores. In contrast to vegetative, multinucleate cells, spore formation requires a strict coordination of mitosis and cytokinesis. It was shown recently that the key regulator of the cell cycle in A. nidulans NimX(Cdc2) and a G(1)/S cyclin, PclA, are transcriptionally upregulated during development. Here we show that PclA accumulates in the nucleus and interacts with NimX(Cdc2). We propose that PclA modulates the kinase activity of NimX(Cdc2) during spore formation.