Poster: Regulation of gene expression

Abs # 771: Characterization of polyadenylation cleavage stimulatory factor homologues in Arabidopsis thaliana

Presenter:	Marion, Amanda W, awmari2@uky.edu
Authors	Marion, Amanda W (A)   Hunt, Arthur G (A)
Affiliations:	(A): University of Kentucky

The formation of a 3’ poly-A tail on eukaryotic mRNAs is an important aspect of gene expression and regulation. This fundamental process has been highly characterized in mammals and yeast. However, less is understood about plant polyadenylation. One polyadenylation factor that has been characterized in mammals is the cleavage stimulatory factor (CstF). CstF is an RNA-binding factor necessary for cleavage but not poly-A addition. CstF helps define the polyadenylation site on the mRNA by the affinity with which it binds a GU-rich downstream element. Four Arabidopsis genes homologous to mammalian and/or yeast CstF subunits have been identified. A single gene encodes each of these homologues, specifically AtCstF77, AtCstF64, AtCstF50, and AtPfs2p. This study uses T-DNA mutants from the Arabidopsis Biological Resource Center to determine if each of these Arabidopsis genes is essential to the life of the plant. The mutants are being analyzed using a genetic approach combined with molecular data obtained from the plant lines. Interactions between these homologues are also being investigated using the yeast-two-hybrid system. Results to date suggest that the AtCstF64 gene is essential, but that the AtCstF50 gene is not. Also AtCstF77 and AtCstF64 have been shown to interact. The results of the mutant analyses and other studies will be presented and discussed. This work is supported by NSF grant MCB0313472.