Phosphatase Subfamily egg

Phosphatase Classification: Fold CC1: Superfamily CC1: Family PTP: Subfamily Egg

Evolution

The egg subfamily is nematode specific. C. elegans has three members: egg-3, egg-4, egg-5.

Domain

The egg subfamily has a single structural domain: a CC1-fold phosphatase domain.

Function

All three C. elegans members are predicted to be catalytically inactive, due to loss of the cysteine or arginine of the Cx5R motif. The near-identical proteins, egg-4 and egg-5, control the oocyte- to-zygote transition by regulating signaling by the DYRK family kinase MBK-2. egg-4/egg-5 binds to MBK-2 at the substrate-binding groove of the kinase, and inhibits the ability of the kinase to bind and phosphorylate substrates, thereby inhibiting downstream signaling [1, 2, 3].

References

1. Cheng KC, Klancer R, Singson A, and Seydoux G. Regulation of MBK-2/DYRK by CDK-1 and the pseudophosphatases EGG-4 and EGG-5 during the oocyte-to-embryo transition. Cell. 2009 Oct 30;139(3):560-72. DOI:10.1016/j.cell.2009.08.047 |
2. Parry JM, Velarde NV, Lefkovith AJ, Zegarek MH, Hang JS, Ohm J, Klancer R, Maruyama R, Druzhinina MK, Grant BD, Piano F, and Singson A. EGG-4 and EGG-5 Link Events of the Oocyte-to-Embryo Transition with Meiotic Progression in C. elegans. Curr Biol. 2009 Nov 3;19(20):1752-7. DOI:10.1016/j.cub.2009.09.015 |
3. Tonks NK. Pseudophosphatases: grab and hold on. Cell. 2009 Oct 30;139(3):464-5. DOI:10.1016/j.cell.2009.10.008 |