Abstract
The addition of a poly(A) tail has been examined in a HeLa cell nuclear extract using SV40 late RNAs that end at or near the natural poly(A) site. We find that the addition of a full-length, 200-nucleotide poly(A) tail occurs in two discrete phases. In the first phase, the addition of each adenosine is dependent on the highly conserved sequence AAUAAA. Mutations in that sequence result in an accumulation of products that contain 9 or fewer adenosine residues. In the second phase, poly(A) addition no longer requires AAUAAA but, instead, requires the oligo(A) primer synthesized during the first phase. Thus, RNAs carrying an AAUAAA mutation and a 3'-terminal oligo(A) segment are extended efficiently to full-length poly(A). The transition between phases occurs with the addition of the tenth adenosine residue. An activity exists that limits the length of poly(A) added in the extract to approximately 200 nucleotides. The two phases share at least one component and are likely to involve the same poly(A) polymerase.
Publisher
Cold Spring Harbor Laboratory
Subject
Developmental Biology,Genetics
Reference46 articles.
1. Barrel, B.G. 1971. Fractionation and sequence analysis of radioactive nucleotides. In Proceeding in nucleic acids research (ed. G.L. Cantonit and D.R. Davies), vol. 2, pp. 751–759. Harper, New York.
2. Transcription termination and 3′ processing: the end is in site!
3. Brownlee, G.G. 1972. Determination of sequences in RNA. Elsevier, New York.
4. 3′ cleavage and polyadenylation of mRNA precursors in vitro requires a poly(A) polymerase, a cleavage factor, and a snRNP
5. Poly(A) polymerase purified from HeLa cell nuclear extract is required for both cleavage and polyadenylation of pre-mRNA in vitro.;Mol. Cell. Biol.,1989
Cited by
87 articles.
订阅此论文施引文献
订阅此论文施引文献，注册后可以免费订阅5篇论文的施引文献，订阅后可以查看论文全部施引文献