Cyclin aggregation and robustness of bio-switching.
During the cell cycle, Cdc2-cyclin B kinase abruptly becomes active and triggers the entry into mitosis/meiosis. Recently, it was found that inactive Cdc2-cyclin B is present in aggregates in immature starfish oocytes and becomes disaggregated at the time of its activation during maturation. We discuss a possible scenario in which aggregation of Cdc2-cyclin B dramatically enhances robustness of this activation. In this scenario, only inactive Cdc2-cyclin B can form aggregates, and the aggregates are in equilibrium with inactive Cdc2-cyclin B in solution. During maturation, the hormone-triggered inactivation of Myt1 depletes the soluble inactive Cdc2-cyclin B and the turnover leads to dissolution of the aggregates. This phase change, when coupled with the instability of the signaling network, provides a robust bio-switch.
Slepchenko
Boris M
BM
Center for Biomedical Imaging Technology, Department of Physiology, University of Connecticut Health Center, Farmington, Connecticut 06032, USA. boris@neuron.uchc.edu
Terasaki
Mark
M
D000818:Animals; D016203:CDC2 Protein Kinase / Q000378:metabolism*; D019926:Cyclin B / Q000378:metabolism*; D008540:Meiosis; D008938:Mitosis; D008962:Models, Theoretical; D009865:Oocytes / Q000378:metabolism*; D015398:Signal Transduction; D013215:Starfish / Q000196:embryology / Q000378:metabolism*
D019926:Cyclin B; D016203:CDC2 Protein Kinase