Angelika Amon (1967-2020):Breakthrough scientist, extraordinary mentor, and loyal friend

Visintin and Marston discuss the life and achievements of Angelika Amon, who passed away on October 29, 2020

Oscillations in Cdc14 release and sequestration reveal a circuit underlying mitotic exit

The phosphatase Cdc14 exerts negative feedback on its upstream regulators to limit its release from the nucleolus to once per cell cycle

Cdc14B and APC/C Tackle DNA Damage

Mitotic exit in budding yeast is regulated by the proteins Cdc14, APC/CCdh1, and Plk1. In this issue, Bassermann and colleagues (2008) show that this network of proteins has been rewired in human cells to control the cell cycle in response to DNA damage

The Role of the Polo Kinase Cdc5 in Controlling Cdc14 Localization

In budding yeast, the protein phosphatase Cdc14 controls exit from mitosis. Its activity is regulated by a competitive inhibitor Cfi1/Net1, which binds to and sequesters Cdc14 in the nucleolus. During anaphase, Cdc14 is released from its inhibitor by the action of two regulatory networks. The Cdc Fourteen Early Anaphase Release (FEAR) network initiates Cdc14 release from Cfi1/Net1 during early anaphase, and the Mitotic Exit Network (MEN) promotes Cdc14 release during late anaphase. Here, we investigate the relationship among FEAR network components and propose an order in which they function to promote Cdc14 release from the nucleolus. Furthermore, we examine the role of the protein kinase Cdc5, which is a component of both the FEAR network and the MEN, in Cdc14 release from the nucleolus. We find that overexpression of CDC5 led to Cdc14 release from the nucleolus in S phase-arrested cells, which correlated with the appearance of phosphorylated forms of Cdc14 and Cfi1/Net1. Cdc5 promotes Cdc14 phosphorylation and, by stimulating the MEN, Cfi1/Net1 phosphorylation. Furthermore, we suggest that Cdc14 release from the nucleolus only occurs when Cdc14 and Cfi1/Net1 are both phosphorylated