Research Paper Volume 11, Issue 4 pp 1110—1128

The ubiquitin ligase KBTBD8 regulates PKM1 levels via Erk1/2 and Aurora A to ensure oocyte quality

Yan-Ru Li 1, *, , Rui-Rui Peng 1, *, , Wen-Yi Gao 1, *, , Peng Liu 1, 2, *, , Liang-Jian Chen 1, *, , Xiao-Lan Zhang 3, *, , Na-Na Zhang 1, , Yang Wang 1, , Lei Du 1, 4, , Feng-Yu Zhu 1, , Li-Li Wang 1, , Cong-Rong Li 1, , Wen-Tao Zeng 5, , Jian-Min Li 5, , Fan Hu 1, , Dong Zhang 1, , Zhi-Xia Yang 1, ,

  • 1 State Key Lab of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, Jiangsu, P.R. China
  • 2 Reproductive Medical Center, Huzhou Maternity and Child Health Care Hospital, Huzhou 313000, Zhejiang, P.R. China
  • 3 Nanjing Maternity and Child Health Care Hospital, Nanjing 210004, Jiangsu, P.R. China
  • 4 Department of Center for Medical Experiments, Third Xiang-Ya Hospital of Central South University, Changsha 410013, Hunan, P.R. China
  • 5 Animal Core Facility, Nanjing Medical University, Nanjing 211166, Jiangsu, P.R. China
* Equal contribution

received: December 20, 2018 ; accepted: January 24, 2019 ; published: February 20, 2019 ;

https://doi.org/10.18632/aging.101802
How to Cite

Copyright: Li et al. This is an open‐access article distributed under the terms of the Creative Commons Attribution License (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract

Tight control of energy metabolism is essential for normal cell function and organism survival. PKM (pyruvate kinase, muscle) isoforms 1 and 2 originate from alternative splicing of PKM pre-mRNA. They are key enzymes in oxidative phosphorylation and aerobic glycolysis, respectively, and are essential for ATP generation. The PKM1:PKM2 expression ratio changes with development and differentiation, and may also vary under metabolic stress and other conditions. Until now, there have been no reports about the function and regulation of PKM isozymes in oocytes. Here, we demonstrate that PKM1 or PKM2 depletion significantly disrupts ATP levels and mitochondrial integrity, and exacerbates free-radical generation and apoptosis in mouse oocytes. We also show that KBTBD8, a female fertility factor in the KBTBD ubiquitin ligase family, selectively regulates PKM1 levels through a signaling cascade that includes Erk1/2 and Aurora A kinases as intermediates. Finally, using RNA sequencing and protein network analysis, we identify several regulatory proteins that may be govern generation of mature PKM1 mRNA. These results suggest KBTBD8 affects PKM1 levels in oocytes via a KBTBD8→Erk1/2→Aurora A axis, and may also affect other essential processes involved in maintaining oocyte quality.

Abbreviations

KBTBD8: Kelch repeat and BTB domain-containing protein 8; PKM: pyruvate kinase, muscle; GCs: granulosa cells; GV: germinal vesicle; GVBD: germinal vesicle break down; MI: metaphase I; MII: metaphase II; 1PB: first polar body; PN: pronucleus; IP: immunoprecipitate; ROS: reactive oxygen species; PND: post-natal day; RBM: RNA-binding motif; RIPK4: receptor-interacting serine/threonine kinase 4; Lrrc19: leucine rich repeat containing 19; Rrm: RNA recognition motif; hnRNP: heterogeneous nuclear ribonucleoprotein.