In Vivo Evidence that Defects in the Transcriptional Elongation Factors RPB2, TFIIS, and SPT5 Enhance Upstream Poly(A) Site Utilization†
AUTOR(ES)
Cui, Yajun
FONTE
American Society for Microbiology
RESUMO
While a number of proteins are involved in elongation processes, the mechanism for action of most of these factors remains unclear primarily because of the lack of suitable in vivo model systems. We identified in yeast several genes that contain internal poly(A) sites whose full-length mRNA formation is reduced by mutations in RNA polymerase II subunit RPB2, elongation factor SPT5, or TFIIS. RPB2 and SPT5 defects also promoted the utilization of upstream poly(A) sites for genes that contain multiple 3′ poly(A) signaling sequences, supporting a role for elongation in differential poly(A) site choice. Our data suggest that elongation defects cause increased transcriptional pausing or arrest that results in increased utilization of internal or upstream poly(A) sites. Transcriptional pausing or arrest can therefore be visualized in vivo if a gene contains internal poly(A) sites, allowing biochemical and genetic study of the elongation process.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=207619Documentos Relacionados
- Upstream sequence elements enhance poly(A) site efficiency of the C2 complement gene and are phylogenetically conserved.
- Alternative poly(A) site utilization during adenovirus infection coincides with a decrease in the activity of a poly(A) site processing factor.
- Domains in the SPT5 Protein That Modulate Its Transcriptional Regulatory Properties
- TFIIS Enhances Transcriptional Elongation through an Artificial Arrest Site In Vivo
- Poly(A) site selection in the yeast Ty retroelement requires an upstream region and sequence-specific titratable factor(s) in vitro.