Poster abstracts

Poster number 15 submitted by Lavanya Dampanaboina

Role of the 50 KD subunit of Cleavage Stimulation Factor in Polyadenylation in plants

Lavanya Dampanaboina (Plant and Soil Sciences, University of Kentucky), Arthur G. Hunt (Plant and Soil Sciences, University of Kentucky)

Abstract:
Polyadenylation in plants requires at least three cis elements. They are far upstream element (FUE), near upstream element (NUE) and cleavage/ polyadenylation site. These elements act as poly(A) signals and are recognized by a set of polyadenylation factors. Cleavage stimulation factor (CstF) is one of the factors with three different subunits of 77, 64 and 50 kD. The CstF complex plays a main role in the recognition of the downstream GU rich element and aids in cleavage along with other cleavage factors. The present study focuses on the Arabidopsis ortholog of CstF50. Yeast two hybrid assays were employed to study the interactions of CstF50 with other polyadenylation factor subunits. The results of yeast two hybrid shows the positive interactions with CPSF100, CPSF30, two different PAP isoforms, one PabN isoform, and Fip1. The CstF50 interaction with poly(A) polymerase and poly(A) binding protein suggests that it is involved both in cleavage and polyadenylation. These results indicate that plant CstF50 is different from the mammalian CstF50 which has only the cleavage function. Further sub-cellular localization studies are being conducted by fusing CtstF50 with DsRed. Progress along these lines will be presented.

References:
1. Li, Q. and A. G. Hunt (1997). The Polyadenylation of RNA in Plants. 115: 321-325.
2. Takagaki, Y., J. L. Manley, et al. (1990). A multisubunit factor, CstF, is required for polyadenylation of mammalian pre-mRNAs. 4: 2112-2120.

Keywords: Polyadenylation, Yeast two hybrid assay, CstF