Rrp6p controls mRNA poly(A) tail length and its decoration with poly(A) binding proteins.
Poly(A) (pA) tail binding proteins (PABPs) control mRNA polyadenylation, stability, and translation. In a purified system, S. cerevisiae PABPs, Pab1p and Nab2p, are individually sufficient to provide normal pA tail length. However, it is unknown how this occurs in more complex environments. Here we find that the nuclear exosome subunit Rrp6p counteracts the in vitro and in vivo extension of mature pA tails by the noncanonical pA polymerase Trf4p. Moreover, PABP loading onto nascent pA tails is controlled by Rrp6p; while Pab1p is the major PABP, Nab2p only associates in the absence of Rrp6p. This is because Rrp6p can interact with Nab2p and displace it from pA tails, potentially leading to RNA turnover, as evidenced for certain pre-mRNAs. We suggest that a nuclear mRNP surveillance step involves targeting of Rrp6p by Nab2p-bound pA-tailed RNPs and that pre-mRNA abundance is regulated at this level.
Centre for mRNP Biogenesis and Metabolism, Department of Molecular Biology and Genetics, Aarhus University, C.F. Møllers Alle 3, Building 1130, DK-8000 Aarhus C., Denmark.
Manfred
M
Schmid
Mathias Bach
MB
Poulsen
Pawel
P
Olszewski
Vicent
V
Pelechano
Cyril
C
Saguez
Ishaan
I
Gupta
Lars M
LM
Steinmetz
Claire
C
Moore
Torben Heick
TH
Jensen
D001483:Base Sequence; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism; D005095:Exoribonucleases / Q000378:metabolism*; D063326:Exosome Multienzyme Ribonuclease Complex; D055354:Exosomes / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D008954:Models, Biological; D008969:Molecular Sequence Data; D029543:Nucleocytoplasmic Transport Proteins / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D011061:Poly A / Q000737:chemistry* / Q000235:genetics; D039102:Poly(A)-Binding Proteins / Q000378:metabolism*; D011485:Protein Binding; D012313:RNA / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*
C080773:NAB2 protein, S cerevisiae; D029543:Nucleocytoplasmic Transport Proteins; D039102:Poly(A)-Binding Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins; C450100:pab1 protein, S cerevisiae; D011061:Poly A; D012313:RNA; D004259:DNA-Directed DNA Polymerase; C487545:PAP2 protein, S cerevisiae; D005095:Exoribonucleases; D063326:Exosome Multienzyme Ribonuclease Complex; C112610:RRP6 protein, S cerevisiae