Controlling centrosome number: licenses and blocks.
Centrosomes organize microtubule structures in animal cells. The centrosome duplicates once per cell cycle in most dividing cells via a pathway that relies on a pre-existing centrosome. The molecular mechanism of this 'once and only once' control is not understood, and recent results show that centrosomes can also be assembled by a de novo pathway that bypasses this control. These results require a rethinking of how proper centrosome number is maintained. We propose that the engagement of centrioles with each other normally blocks centrosome re-duplication, and that disengagement of centrioles from each other at the end of mitosis licenses them for duplication in the subsequent cell cycle.
Tsou
Meng-Fu Bryan
MF
Department of Biological Sciences, Stanford University, Stanford, California 94305, USA.
Stearns
Tim
T
D000818:Animals; D002453:Cell Cycle; D018385:Centrosome / Q000737:chemistry* / Q000378:metabolism; D051357:Cyclin-Dependent Kinase 2 / Q000502:physiology*; D016213:Cyclins / Q000502:physiology*; D008954:Models, Biological; D009687:Nuclear Proteins / Q000502:physiology*; D000090243:Nucleophosmin
D016213:Cyclins; D009687:Nuclear Proteins; D000090243:Nucleophosmin; D051357:Cyclin-Dependent Kinase 2