Germline quality control: eEF2K stands guard to eliminate defective oocytes

Dev Cell. 2014 Mar 10;28(5):561-572. doi: 10.1016/j.devcel.2014.01.027. Epub 2014 Feb 27.

Abstract

The control of germline quality is critical to reproductive success and survival of a species; however, the mechanisms underlying this process remain unknown. Here, we demonstrate that elongation factor 2 kinase (eEF2K), an evolutionarily conserved regulator of protein synthesis, functions to maintain germline quality and eliminate defective oocytes. We show that disruption of eEF2K in mice reduces ovarian apoptosis and results in the accumulation of aberrant follicles and defective oocytes at advanced reproductive age. Furthermore, the loss of eEF2K in Caenorhabditis elegans results in a reduction of germ cell death and significant decline in oocyte quality and embryonic viability. Examination of the mechanisms by which eEF2K regulates apoptosis shows that eEF2K senses oxidative stress and quickly downregulates short-lived antiapoptotic proteins, XIAP and c-FLIPL by inhibiting global protein synthesis. These results suggest that eEF2K-mediated inhibition of protein synthesis renders cells susceptible to apoptosis and functions to eliminate suboptimal germ cells.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Apoptosis*
  • Blotting, Western
  • Caenorhabditis elegans / cytology
  • Caenorhabditis elegans / physiology*
  • Caspases / metabolism
  • Cells, Cultured
  • Elongation Factor 2 Kinase / physiology*
  • Embryo, Mammalian / cytology
  • Embryo, Mammalian / metabolism
  • Female
  • Fibroblasts / cytology
  • Fibroblasts / metabolism
  • Germ Cells / pathology*
  • Immunoenzyme Techniques
  • In Situ Nick-End Labeling
  • Male
  • Mice
  • Mice, Knockout
  • NIH 3T3 Cells
  • Oocytes / cytology
  • Oocytes / physiology*
  • Ovary / cytology
  • Ovary / physiology
  • Phosphorylation
  • Quality Control*

Substances

  • Eef2k protein, mouse
  • Elongation Factor 2 Kinase
  • Caspases