The upstream sequence element of the C2 complement poly(A) signal activates mRNA 3 ' end formation by two distinct mechanisms

• Type: Article in International Scientific Journal
• Date: 1998

Authors

Moreira, A (Author) REIT; Takagaki, Y (Author) Other; Brackenridge, S (Author) Other; Wollerton, M (Author) Other; Manley, JL (Author) Other; Proudfoot, NJ (Author) Other

Journal

Title: GENES & DEVELOPMENT

Vol. 12

Pages: 2522-2534

ISSN: 0890-9369

Indexing

ISI Web of Knowledge - 118 Citations

Scopus - 118 Citations

Other information

Authenticus ID: P-001-79S

DOI: 10.1101/gad.12.16.2522

Abstract (EN): The poly(A) signal of the C2 complement gene is unusual in that it possesses an upstream sequence element (USE) required for full activity in vivo. We describe here in vitro experiments demonstrating that this USE enhances both the cleavage and poly(A) addition reactions, We also show that the C2 USE can be cross-linked efficiently to a 55-kD protein that we identify as the polypyrimidine tract-binding protein (PTB), implicated previously in modulation of pre-mRNA splicing, Mutation of the PTB-binding site significantly reduces the efficiency of the C2 poly(A) site both in vivo and in vitro. Furthermore, addition of PTB to reconstituted processing reactions enhances cleavage at the C2 poly(A) site, indicating that PTB has a direct Pole in recognition of this signal. The C2 USE, however, also increases the affinity of general polyadenylation factors independently for the C2 poly(A) signal as detected by enhanced binding of cleavage-stimulaton factor (CstF). Strikingly, this leads to a novel CstF-dependant enhancement of the poly(A) synthesis phase of the reaction. These studies both emphasize the interconnection between splicing and polyadenylation and indicate an unexpected flexibility in the organization of mammalian poly(A) sites.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 13