Molecular Genetics and Genomics

, Volume 280, Issue 3, pp 211–221

Synthetic lethality between eIF5A and Ypt1 reveals a connection between translation and the secretory pathway in yeast

Authors

  • Mariana C. Frigieri
    • Department of Biological Sciences, School of Pharmaceutical SciencesSão Paulo State University, UNESP
  • Marcus V. S. João Luiz
    • Department of Biological Sciences, School of Pharmaceutical SciencesSão Paulo State University, UNESP
  • Luciano H. Apponi
    • Department of Biological Sciences, School of Pharmaceutical SciencesSão Paulo State University, UNESP
  • Cleslei F. Zanelli
    • Department of Biological Sciences, School of Pharmaceutical SciencesSão Paulo State University, UNESP
    • Department of Biological Sciences, School of Pharmaceutical SciencesSão Paulo State University, UNESP
Original Paper

DOI: 10.1007/s00438-008-0357-y

Cite this article as:
Frigieri, M.C., João Luiz, M.V.S., Apponi, L.H. et al. Mol Genet Genomics (2008) 280: 211. doi:10.1007/s00438-008-0357-y

Abstract

The putative translation initiation factor 5A (eIF5A) is a small protein, highly conserved and essential in all organisms from archaea to mammals. Although the involvement of eIF5A in translation initiation has been questioned, new evidence reestablished the connection between eIF5A and this cellular process. In order to better understand the function of elF5A, a screen for synthetic lethal gene using the tif51A-3 mutant was carried out and a new mutation (G80D) was found in the essential gene YPT1, encoding a protein involved in vesicular trafficking. The precursor form of the vacuolar protein CPY is accumulated in the ypt1-G80D mutant at the nonpermissive temperature, but this defect in vesicular trafficking did not occur in the tif51A mutants tested. Overexpression of eIF5A suppresses the growth defect of a series of ypt1 mutants, but this suppression does not restore correct CPY sorting. On the other hand, overexpression of YPT1 does not suppress the growth defect of tif51A mutants. Further, it was revealed that eIF-5A is present in both soluble and membrane fractions, and its membrane association is ribosome-dependent. Finally, we demonstrated that the ypt1 and other secretion pathway mutants are sensitive to paromomycin. These results confirm the link between translation and vesicular trafficking and reinforce the implication of eIF5A in protein synthesis.

Keywords

eIF5AYpt1Synthetic lethalityGenetic interactionVesicular traffickingProtein synthesis

Copyright information

© Springer-Verlag 2008