Figure 5.

Model for how SUMOylation of ZTF-8 regulates its germline functions. In wild-type animals, we propose that SUMOylation (blue circle) of ZTF-8 is required for meiotic DSBR as well as for the proper localization of the 9-1-1 complex, which results in DNA damage checkpoint activation (left). An interaction with a yet unknown SUMOylated protein(s) (gray oval with blue circle), perhaps via a SIM (SUMO interaction motif) at ZTF-8, could explain how the non-SUMOylatable ZTF-8 is still localized properly; however, it does lead to inefficient DSBR and DDR activation due to lack of interactions between ZTF-8 and the 9-1-1 complex (middle). A defective SUMOylation pathway may hinder the proper localization of ZTF-8 due to the absence of SUMOylation in another protein (gray oval), and this leads to impaired DSBR and DDR (right).