A synthetic A tail rescues yeast nuclear accumulation of a ribozyme-terminated transcript.
To investigate the role of 3' end formation in yeast mRNA export, we replaced the mRNA cleavage and polyadenylation signal with a self-cleaving hammerhead ribozyme element. The resulting RNA is unadenylated and accumulates near its site of synthesis. Nonetheless, a significant fraction of this RNA reaches the cytoplasm. Nuclear accumulation was relieved by insertion of a stretch of DNA-encoded adenosine residues immediately upstream of the ribozyme element (a synthetic A tail). This indicates that a 3' stretch of adenosines can promote export, independently of cleavage and polyadenylation. We further show that a synthetic A tail-containing RNA is unaffected in 3' end formation mutant strains, in which a normally cleaved and polyadenylated RNA accumulates within nuclei. Our results support a model in which a polyA tail contributes to efficient mRNA progression away from the gene, most likely through the action of the yeast polyA-tail binding protein Pab1p.
Dower
Ken
K
Howard Hughes Medical Institute, Department of Biology, Brandeis University, 415 South Street, Waltham, MA 02454, USA.
Kuperwasser
Nicolas
N
Merrikh
Houra
H
Rosbash
Michael
M
D001483:Base Sequence; D002467:Cell Nucleus / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D017404:In Situ Hybridization, Fluorescence; D008954:Models, Biological; D009154:Mutation; D011061:Poly A / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D039102:Poly(A)-Binding Proteins / Q000235:genetics / Q000378:metabolism; D016337:RNA, Catalytic / Q000378:metabolism*; D012331:RNA, Fungal / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic
D039102:Poly(A)-Binding Proteins; D016337:RNA, Catalytic; D012331:RNA, Fungal; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; C427204:hammerhead ribozyme; C450100:pab1 protein, S cerevisiae; D049452:Green Fluorescent Proteins; D011061:Poly A