Nuclear distribution of eIF3g and its interacting nuclear proteins in breast cancer cells

Mol Med Rep. 2016 Apr;13(4):2973-80. doi: 10.3892/mmr.2016.4935. Epub 2016 Feb 23.

Abstract

Eukaryotic translation initiation factor 3 subunit g (eIF3g) is a core subunit of the eukaryotic translation initiation factor 3 complex, and is important in the initiation of translation. It is also involved in caspase-mediated apoptosis, and is upregulated in multidrug-resistant cancer cells. In the present study, the nuclear distribution of eIF3g was determined by performing co-immunoprecipitation of proteins that potentially interact with eIF3g in the nucleus. Mass spectrometry characterization showed that three proteins, heterogeneous nuclear ribonucleoprotein U/scaffold attachment factor A, HSZFP36/zinc finger protein 823 and β‑actin, were among the candidate eIF3g‑interacting proteins in the nucleus. The protein‑protein interaction was further confirmed by cross‑linking and a glutathione S‑transferase pull‑down assay, followed by western blotting. The co‑localization of these proteins was determined by confocal microscopy. These findings provide novel insight into the possible functions of eIF3g in the nucleus and serves as an important first step for further investigation of the roles of eIF3g in cancer development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / metabolism
  • Breast Neoplasms / genetics
  • Breast Neoplasms / metabolism*
  • Cell Line, Tumor
  • Cell Nucleus / metabolism*
  • Computational Biology / methods
  • Eukaryotic Initiation Factor-3 / genetics
  • Eukaryotic Initiation Factor-3 / metabolism*
  • Female
  • Gene Expression
  • Heterogeneous-Nuclear Ribonucleoprotein U / metabolism
  • Humans
  • Nuclear Proteins / metabolism*
  • Protein Binding
  • Protein Interaction Mapping
  • Protein Transport

Substances

  • Actins
  • Eukaryotic Initiation Factor-3
  • Heterogeneous-Nuclear Ribonucleoprotein U
  • Nuclear Proteins