Polyadenylation of rRNA in Saccharomyces cerevisiae
AUTOR(ES)
Kuai, Letian
FONTE
National Academy of Sciences
RESUMO
In contrast to mRNAs, rRNAs are transcribed by RNA polymerase I or III and are not believed to be polyadenylated. Here we show that in Saccharomyces cerevisiae, at least a small fraction of rRNAs do have a poly(A) tail. The levels of polyadenylated rRNAs are dramatically increased in strains lacking the degradation function of Rrp6p, a component of the nuclear exosome. Pap1p, the poly(A) polymerase, is responsible for adenylating the rRNAs despite the fact that the rRNAs do not have a canonical polyadenylation signal. Polyadenylated rRNAs reside mainly within the nucleus and are in turn degraded. For at least one rRNA type, the polyadenylation preferentially occurs on the precursor rather than the mature product. The existence of polyadenylated rRNAs may reflect a quality-control mechanism of rRNA biogenesis.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=423237Documentos Relacionados
- The rRNA enhancer regulates rRNA transcription in Saccharomyces cerevisiae.
- Saturation Mutagenesis of 5S rRNA in Saccharomyces cerevisiae
- A new rRNA processing mutant of Saccharomyces cerevisiae.
- Cross Talk between tRNA and rRNA Synthesis in Saccharomyces cerevisiae
- A polymerase switch in the synthesis of rRNA in Saccharomyces cerevisiae.