Accumulation of mRNA coding for the ctf13p kinetochore subunit of Saccharomyces cerevisiae depends on the same factors that promote rapid decay of nonsense mRNAs.
The CTF13 gene codes for a subunit of the kinetochore in Saccharomyces cerevisiae. The temperature-sensitive mutation ctf13-30, which confers reduced fidelity of chromosome transmission, is a G --> A transition causing an amino acid substitution of Lys for Glu146. Strains carrying one chromosomal copy of ctf13-30 fail to grow at the restrictive temperature, whereas a haploid strain carrying two copies of ctf13-30 can grow. Four genes, UPF1, UPF2, UPF3, and ICK1, were represented among extragenic suppressors of ctf13-30. The UPF genes encode proteins that promote rapid decay of pre-mRNAs and mRNAs containing a premature stop codon. Suppressor mutations in these genes restore kinetochore function by causing increased accumulation of ctf13-30 mRNA. They also cause increased accumulation of CYH2 pre-mRNA, which is a natural target of UPF-mediated decay. Mutations in ICK1 restore kinetochore function but have no effect on ctf13-30 mRNA or CYH2 pre-mRNA accumulation. Most importantly, loss of UPF1 function causes increased accumulation of wild-type CTF13 mRNA but has no effect on the mRNA half-life. We propose that UPF-mediated decay modulates the mRNA level of one or more factors involved in CTF13 mRNA expression.
Dahlseid
J N
JN
Laboratories of Genetics and Molecular Biology, University of Wisconsin, Madison, Wisconsin 53706, USA.
Puziss
J
J
Shirley
R L
RL
Atkin
A L
AL
Hieter
P
P
Culbertson
M R
MR
D005656:Fungal Proteins / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D018386:Kinetochores; D009687:Nuclear Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins
C081354:CTF13 protein, S cerevisiae; D005656:Fungal Proteins; D009687:Nuclear Proteins; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins