Accelerated mRNA decay in conditional mutants of yeast mRNA capping enzyme. Academic Article uri icon

Overview

abstract

  • Current models of mRNA decay in yeast posit that 3' deadenylation precedes enzymatic removal of the 5' cap, which then exposes the naked end to 5' exonuclease action. Here, we analyzed gene expression in Saccharomyces cerevisiae cells bearing conditional mutations of Ceg1 (capping enzyme), a 52 kDa protein that transfers GMP from GTP to the 5' end of mRNA to form the GpppN cap structure. Shift of ceg1 mutants to restrictive temperature elicited a rapid decline in the rate of protein synthesis, which correlated with a sharp reduction in the steady-state levels of multiple individual mRNAs. ceg1 mutations prevented the accumulation of SSA1 and SSA4 mRNAs that were newly synthesized at the restrictive temperature. Uncapped poly(A)+ SSA4 mRNA accumulated in cells lacking the 5' exoribonuclease Xrn1. These findings provide genetic evidence for the long-held idea that the cap guanylate is critical for mRNA stability. The deadenylation-decapping-degradation pathway appears to be short-circuited when Ceg1 is inactivated.

publication date

  • May 1, 1998

Research

keywords

  • Nucleotidyltransferases
  • RNA Caps
  • RNA, Fungal
  • RNA, Messenger
  • Saccharomyces cerevisiae
  • Saccharomyces cerevisiae Proteins

Identity

PubMed Central ID

  • PMC147543

Scopus Document Identifier

  • 0032077454

Digital Object Identifier (DOI)

  • 10.1093/nar/26.9.2050

PubMed ID

  • 9547258

Additional Document Info

volume

  • 26

issue

  • 9