Figure 4.

Mei2 titrates out inhibitors of meiosis. During early meiosis Mei2 binds to meiRNA, which binds Mmi1 protein, thus sequestering Mmi1. Mei2 also binds mmi1 mRNA, and probably prevents synthesis of new Mmi1 protein. Mei2 also binds rep2 mRNA, and probably prevents synthesis of new Rep2 protein. Titration of these three meiotic inhibitors (Mmi1, mmi1 mRNA, and rep2 mRNA) facilitate initiation of meiosis. The mechanism by which Mei2 forms a dot (here shown as a speculative Mei2–Mei2 protein–protein interaction) is unknown. Also unknown is whether the Mmi1 binding sites on the mmi1 mRNA participate in the titration of Mmi1 protein.