Figure 3.

Upon replicative stress, WEE1 targets at least two substrates to efficiently establish a blockage in G1/S transition. As an important DDR player in plant, WEE1 is activated in an ATR/SOG1-dependant manner. If WEE1 implication during G2/M phase transition has been already described, recent works highlight its implication during the G1/S phase transition. 1—By phosphorylating the FBL17 E3 ubiquitin ligase, WEE1 triggers its proteasome degradation resulting in further accumulation of KRPs, which block the cell cycle progression [123]. FBL17 being also recruited at DNA lesion sites could target other regulators to fine tune DNA repair mechanisms [112]. 2—By targeting PRL1 a subunit of the MAC complex involved in RNA splicing, WEE1 promotes its selective degradation resulting in a non-functional MAC complex. As a consequence, CYCD mRNAs are not properly spliced compromising the activation of CDKAs and the cell cycle progression [124].