fig1

Figure 1. Crosstalk between mitochondria dynamics and the cell cycle. Model showing the changes in mitochondria dynamics and Drp1 activity throughout the cell cycle. Mitochondria fusion is favored in G1 and mitochondria fission is dominant in mitosis. This leads to the formation of a highly elongated and interconnected network during late G1, and small disconnected mitochondria in mitosis. Changes in mitochondria dynamics are regulated by the cell cycle machinery, for example mitochondria fission is favored in mitosis by Drp1 phosphorylation by the mitotic kinase Cyclin B1/Cdk1. Conversely, mitochondria fusion is favored in G1 due, at least in part, to degradation of Drp1 by the ubiquitin ligase APC/C-Cdh1 in early G1. In turn, these changes in mitochondria morphology regulate the cell cycle. Hyperfused mitochondria promote the G1/S transition, while inhibition of Drp1 induces a G2 arrest and failure to fragment mitochondria in mitosis can interfere with cytokinesis. These phenotypes have started to reveal a profound level of cross-talk between these two processes