Point mutations upstream of the yeast ADH2 poly(A) site significantly reduce the efficiency of 3'-end formation.
AUTOR(ES)
Hyman, L E
RESUMO
The sequences directing formation of mRNA 3' ends in Saccharomyces cerevisiae are not well defined. This is in contrast to the situation in higher eukaryotes in which the sequence AAUAAA is known to be crucial to proper 3'-end formation. The AAUAAA hexanucleotide is found upstream of the poly(A) site in some but not all yeast genes. One of these is the gene coding for alcohol dehydrogenase, ADH2. Deletion or a double point mutation of the AAUAAA has only a small effect on the efficiency of the reaction, and in contrast to the mammalian system, it is most likely not operating as a major processing signal in the yeast cell. However, we isolated point mutations which reveal that a region located approximately 80 nucleotides upstream of the poly(A) site plays a critical role in either transcription termination, polyadenylation, or both. These mutations represent the first point mutations in yeasts which significantly reduce the efficiency of 3'-end formation.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=359886Documentos Relacionados
- 3'-end labeling of RNA with recombinant yeast poly(A) polymerase.
- Multiple forms of poly(A) polymerases purified from HeLa cells function in specific mRNA 3'-end formation.
- Polyomavirus early region alternative poly(A) site: 3'-end heterogeneity and altered splicing pattern.
- A single point mutation in the yeast TRP4 gene affects efficiency of mRNA 3' end processing and alters selection of the poly(A) site.
- Point mutations in the stem-loop at the 3' end of mouse histone mRNA reduce expression by reducing the efficiency of 3' end formation.