The eIF4E-binding protein Eap1 has similar but independent roles in cell growth and gene expression with the cytoplasmic deadenylase Ccr4

Biosci Biotechnol Biochem. 2021 May 25;85(6):1452-1459. doi: 10.1093/bbb/zbab056.

Abstract

eIF4E-binding proteins (4E-BPs) are translational repressors that compete with eIF4G for binding to eIF4E. Here we investigated the roles of yeast 4E-BPs, Eap1, and Caf20 in cell wall integrity pathway and gene expression. We found that eap1∆ mutation, but not caf20∆ mutation, showed synthetic growth defect with mutation in ROM2 gene encoding Rho1 GEF. The eap1∆ mutation also showed synthetic lethality with mutation in CCR4 gene encoding cytoplasmic deadenylase. Ccr4 functions in the degradation of LRG1 mRNA encoding Rho1 GAP. Eap1-Y109A L114A, which could not bind to eIF4E, did not suppress the synthetic lethality of eap1∆ ccr4∆ mutant, suggesting that 4E-binding of Eap1 is important for its function. We also found that eap1∆ mutant showed the derepression of stress response gene HSP12. 4E-binding of Eap1 was also required for the repression of HSP12 expression. Our results indicate that Eap1 has similar but independent roles in cell growth and gene expression with Ccr4.

Keywords: 4E-BP; Ccr4; Eap1; gene expression; yeast.

MeSH terms

  • Cell Proliferation*
  • Gene Expression Regulation, Fungal*
  • Mutation
  • Ribonucleases / genetics*
  • Saccharomyces cerevisiae / cytology*
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / genetics*
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Transcription Factors / metabolism*

Substances

  • Eap1 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Transcription Factors
  • CCR4 protein, S cerevisiae
  • Ribonucleases