The Gag protein PEG10 binds to RNA and regulates trophoblast stem cell lineage specification

PLoS One. 2019 Apr 5;14(4):e0214110. doi: 10.1371/journal.pone.0214110. eCollection 2019.

Abstract

Peg10 (paternally expressed gene 10) is an imprinted gene that is essential for placental development. It is thought to derive from a Ty3-gyspy LTR (long terminal repeat) retrotransposon and retains Gag and Pol-like domains. Here we show that the Gag domain of PEG10 can promote vesicle budding similar to the HIV p24 Gag protein. Expressed in a subset of mouse endocrine organs in addition to the placenta, PEG10 was identified as a substrate of the deubiquitinating enzyme USP9X. Consistent with PEG10 having a critical role in placental development, PEG10-deficient trophoblast stem cells (TSCs) exhibited impaired differentiation into placental lineages. PEG10 expressed in wild-type, differentiating TSCs was bound to many cellular RNAs including Hbegf (Heparin-binding EGF-like growth factor), which is known to play an important role in placentation. Expression of Hbegf was reduced in PEG10-deficient TSCs suggesting that PEG10 might bind to and stabilize RNAs that are critical for normal placental development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis Regulatory Proteins
  • Cell Differentiation / genetics*
  • Cell Lineage / genetics
  • DNA Transposable Elements / genetics
  • DNA-Binding Proteins
  • Female
  • Gene Expression Regulation, Developmental
  • Gene Products, gag / genetics
  • Genomic Imprinting / genetics
  • Heparin-binding EGF-like Growth Factor / genetics*
  • Humans
  • Mice
  • Nuclear Proteins / genetics*
  • Placenta / metabolism
  • Placentation / genetics*
  • Pregnancy
  • RNA-Binding Proteins / genetics
  • Stem Cells / cytology
  • Stem Cells / metabolism
  • Transcription Factors / genetics*
  • Trophoblasts / cytology
  • Trophoblasts / metabolism

Substances

  • Apoptosis Regulatory Proteins
  • DNA Transposable Elements
  • DNA-Binding Proteins
  • Gene Products, gag
  • Hbegf protein, mouse
  • Heparin-binding EGF-like Growth Factor
  • Nuclear Proteins
  • Peg10 protein, mouse
  • RNA-Binding Proteins
  • Transcription Factors

Grants and funding

All work was funded by Genentech. Authors MA, EV, HB, PL, DSK, RR, SK, JDW, SG, MR, KRA, RJN, MR-G, ZM, KN, and VMD were employees of Genentech. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section.