Cytoplasmic post-transcriptional modification of mRNA transcripts in the form of polyadenylated (poly(A)) tails plays a key role in their translational control. The timing and degree of polyadenylation has been shown to be due in part to a consensus nucleotide sequence -cytoplasmic polyadenylation elements (CPEs) which can be detected by a polyadenylation element binding protein (CPEB). An indi...

Long-term changes in synaptic efficacy may require the regulated translation of dendritic mRNAs. While the basis of such regulation is unknown, it seemed possible that some features of translational control in development could be recapitulated in neurons. Polyadenylation-induced translation of oocyte mRNAs requires the cis-acting CPE sequence and the CPE-binding protein CPEB. CPEB is also pres...

Cytoplasmic polyadenylation is one mechanism that regulates translation in early animal development. In Xenopus oocytes, polyadenylation of dormant mRNAs, including cyclin B1, is controlled by the cis-acting cytoplasmic polyadenylation element (CPE) and hexanucleotide AAUAAA through associations with CPEB and CPSF, respectively. Previously, we demonstrated that the scaffold protein symplekin co...

GLD-2 is a cytoplasmic poly(A) polymerase present in the Caenorhabditis elegans germ line and embryo. It is a divergent member of the DNA polymerase beta nucleotidyl transferase superfamily, which includes CCA-adding enzymes, DNA polymerases and eukaryotic nuclear poly(A) polymerases. The polyadenylation activity of GLD-2 is stimulated by physical interaction with an RNA binding protein, GLD-3....

Although usually implicated in the stabilization of mRNAs in eukaryotes, polyadenylation was initially shown to destabilize RNA in bacteria. All the data are consistent with polyadenylation being part of a quality control process targeting folded RNA fragments and non-functional RNA molecules to degradation. We report here an example in Escherichia coli, where polyadenylation directly controls ...

Untranslated regions (UTR) play important roles in the posttranscriptional regulation of mRNA processing. There is a wealth of UTR-related information to be mined from the rapidly accumulating EST collections. A computational tool, UTR-extender, has been developed to infer UTR sequences from genomically aligned ESTs. It can completely and accurately reconstruct 72% of the 3' UTRs and 15% of the...

mRNA polyadenylation is responsible for the 3' end formation of most mRNAs in eukaryotic cells and is linked to termination of transcription. Prediction of mRNA polyadenylation sites [poly(A) sites] can help identify genes, define gene boundaries, and elucidate regulatory mechanisms. Current methods for poly(A) site prediction achieve moderate sensitivity and specificity. Here, we present a met...

RNA polymerase II transcribes genes encoding proteins and a large number of small stable RNAs. While pre-mRNA 3'-end formation requires a machinery ensuring tight coupling between cleavage and polyadenylation, small RNAs utilize polyadenylation-independent pathways. In yeast, specific factors required for snRNA and snoRNA 3'-end formation were characterized as components of the APT complex that...

1-Methyladenosine modification at position 58 of tRNA is catalyzed by a two-subunit methyltransferase composed of Trm6p and Trm61p in Saccharomyces cerevisiae. Initiator tRNA (tRNAi(Met)) lacking m1A58 (hypomethylated) is rendered unstable through the cooperative function of the poly(A) polymerases, Trf4p/Trf5p, and the nuclear exosome. We provide evidence that a catalytically active Trf4p poly...