Getting to S: CDK functions and targets on the path to cell-cycle commitment [version 1; referees: 2 approved]

How and when eukaryotic cells make the irrevocable commitment to divide remain central questions in the cell-cycle field. Parallel studies in yeast and mammalian cells seemed to suggest analogous control mechanisms operating during the G1 phase—at Start or the restriction (R) point, respectively—to integrate nutritional and developmental signals and decide between distinct cell fates: cell-cycle arrest or exit versus irreversible commitment to a round of division. Recent work has revealed molecular mechanisms underlying this decision-making process in both yeast and mammalian cells but also cast doubt on the nature and timing of cell-cycle commitment in multicellular organisms. These studies suggest an expanded temporal window of mitogen sensing under certain growth conditions, illuminate unexpected obstacles and exit ramps on the path to full cell-cycle commitment, and raise new questions regarding the functions of cyclin-dependent kinases (CDKs) that drive G1 progression and S-phase entry. Robert P. Fisher ( ) Corresponding author: [email protected] Fisher RP. How to cite this article: Getting to S: CDK functions and targets on the path to cell-cycle commitment [version 1; referees: 2 2016, (F1000 Faculty Rev):2374 (doi: ) approved] F1000Research 5 10.12688/f1000research.9463.1 © 2016 Fisher RP. This is an open access article distributed under the terms of the , which Copyright: Creative Commons Attribution Licence permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Work in the lab is supported by National Institutes of Health grants GM104291 and GM105773. Grant information: Competing interests: The author declares that he has no competing interests. 26 Sep 2016, (F1000 Faculty Rev):2374 (doi: ) First published: 5 10.12688/f1000research.9463.1 Referee Status: