Current Genetics

, Volume 10, Issue 10, pp 733–739

The cellular level of yeast ribosomal protein L25 is controlled principally by rapid degradation of excess protein


  • Tarek T. A. L. ElBaradi
    • Biochemisch LaboratoriumVrije Universiteit
  • Carine A. F. M. van der Sande
    • Biochemisch LaboratoriumVrije Universiteit
  • Willem H. Mager
    • Biochemisch LaboratoriumVrije Universiteit
  • Hendrik A. Raué
    • Biochemisch LaboratoriumVrije Universiteit
  • Rudi J. Planta
    • Biochemisch LaboratoriumVrije Universiteit
Original Articles

DOI: 10.1007/BF00405095

Cite this article as:
ElBaradi, T.T.A.L., van der Sande, C.A.F.M., Mager, W.H. et al. Curr Genet (1986) 10: 733. doi:10.1007/BF00405095


When the gene dosage for the primary rRNA-binding ribosomal protein L25 in yeast cells was raised about 50-fold, the level of mature L25 transcripts was found to increase almost proportionally. The plasmid-derived L25 transcripts were structurally indistinguishable from their genomic counterparts, freely entered polysomes in vivo and were fully translatable in a heterologous in vitro system. Nevertheless, pulse-labelling for periods varying from 3–20 min did not reveal a significant elevation of the intracellular level of L25 protein. When pulse-times were decreased to 10–45 s, however, we did detect a substantial over production of L25. We conclude that, despite the strong RNA-binding capacity of the protein, accumulation of L25 is not controlled by an autogenous (pre-)mRNA-targeted mechanism similar to that operating in bacteria, but rather by extremely rapid degradation of excess protein produced.

Key words

YeastRibosome synthesisRegulationRibosomal protein turnover



ribosomal RNA


ribosomal protein


precursor mRNA

Copyright information

© Springer-Verlag 1986