CELE_T21E3.1, T21E3.1

egg-4 encodes a pseudotyrosine phosphatase; egg-4, along with egg-5 which also encodes a pseudotyrosine phosphatase, are required for the egg-to-oocyte transition and embryonic development; EGG-4 and EGG-5 function to negatively regulate the activity of the MBK-2 DYRK family kinase by sequestering MBK-2 at the oocyte cortex and, in the case of EGG-4, by inhibiting its enzymatic activity; EGG-4 physically interacts with MBK-2 and in in vitro assays, appears to function as a mixed-type inhibitor of MBK-2 kinase activity; EGG-4 localizes to the oocyte cortex and nuclei.

CELE_F44F4.2, F44F4.2

egg-3 encodes a member of the protein tyrosine phosphatase-like (PTPL) family; EGG-3 activity is required for proper regulation of the cell surface and cortical rearrangements that occur during egg activation in response to sperm entry; EGG-3 physically interacts with EGG-4/5 and the MBK-2 kinase to sequester MBK-2 at the oocyte cortex prior to meiosis, thus preventing MBK-2 from phosphorylating its substrates, such as cytoplasmic MEI-1/katanin; EGG-3 initially localizes to the oocyte cortex, but during anaphase of meiosis I moves into the cytoplasm where it is degraded allowing for activation of MBK-2.