title: The interaction between two Arabidopsis polyadenylation factor subunits involves an evolutionarily-conserved motif and has implications for the assembly and function of the polyadenylation complex.
abstract: The polyadenylation factor subunit "Factor Interacting with Poly(A) polymerase" (Fip1) is an important bridging subunit in the eukaryotic polyadenylation complex. To better understand the functioning of Fip1 in Arabidopsis, a random combinatorial screen for peptides that interact with a conserved plant-specific domain in the protein was conducted. A search of the Arabidopsis proteome using these Fip1-binding peptides as queries resulted in the identification of a number of putative Fip1-interacting proteins. One of these was the polyadenylation factor subunit, CstF77. This purported interaction was confirmed by yeast two-hybrid and in vitro assays. Mutation of the motif identified in the phage display screen eliminated the interaction, corroborating the results of the phage display screen. The domain of CstF77 that interacts with Fip1 lies at its extreme C-terminus and is distinct from the part of CstF77 that binds CstF64. Taken together, these results suggest that Fip1 is situated near CstF64 in the polyadenylation complex.
authors.affiliation: Department of Plant and Soil Sciences, University of Kentucky, 345 Plant Science Building, 1405 Veterans Drive, Lexington, KY-40546, USA.
authors.forename: Balasubrahmanyam
authors.initials: B
authors.lastname: Addepalli
authors.forename: Arthur G
authors.initials: AG
authors.lastname: Hunt
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D017360:Arabidopsis; D029681:Arabidopsis Proteins / Q000737:chemistry* / Q000378:metabolism*; D039241:Cleavage Stimulation Factor / Q000737:chemistry / Q000378:metabolism*; D019295:Computational Biology; D006801:Humans; D008969:Molecular Sequence Data; D050505:Mutant Proteins / Q000737:chemistry / Q000378:metabolism; D010455:Peptides / Q000378:metabolism; D026723:Polyadenylation; D021122:Protein Subunits; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D020798:Two-Hybrid System Techniques; D015003:Yeasts; D039221:mRNA Cleavage and Polyadenylation Factors / Q000737:chemistry / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D039241:Cleavage Stimulation Factor; C528628:CstF77 protein, Arabidopsis; C508088:Fip1 protein, Arabidopsis; D050505:Mutant Proteins; D010455:Peptides; D021122:Protein Subunits; D011994:Recombinant Proteins; D039221:mRNA Cleavage and Polyadenylation Factors