Molecular Cell
Volume 24, Issue 1, 6 October 2006, Pages 139-148
Journal home page for Molecular Cell

Article
Elevated Levels of Two tRNA Species Bypass the Requirement for Elongator Complex in Transcription and Exocytosis

https://doi.org/10.1016/j.molcel.2006.07.031Get rights and content
Under an Elsevier user license
open archive

Summary

The Saccharomyces cerevisiae Elongator complex consisting of the six Elp1–Elp6 proteins has been proposed to participate in three distinct cellular processes: transcriptional elongation, polarized exocytosis, and formation of modified wobble uridines in tRNA. Therefore it was important to clarify whether Elongator has three distinct functions or whether it regulates one key process that leads to multiple downstream effects. Here, we show that the phenotypes of Elongator-deficient cells linking the complex to transcription and exocytosis are suppressed by increased expression of two tRNA species. Elongator is required for formation of the mcm5 group of the modified wobble nucleoside 5-methoxycarbonylmethyl-2-thiouridine (mcm5s2U) in these tRNAs. Hence, in cells with normal levels of these tRNAs, presence of mcm5s2U is crucial for posttranscriptional expression of gene products important in transcription and exocytosis. Our results indicate that the physiologically relevant function of the evolutionary-conserved Elongator complex is in formation of modified nucleosides in tRNAs.

CELLBIO
DNA

Cited by (0)

2

Present address: Department of Molecular Genetics and Microbiology, University of Massachusetts Medical School, Worcester, Massachusetts 01655.