title: Arabidopsis thaliana PRP40s are RNA polymerase II C-terminal domain-associating proteins.
abstract: The carboxyl-terminal domain (CTD) of the largest subunit of RNA polymerase II functions as a scaffold for RNA processing machineries that recognize differentially phosphorylated conserved (YSPTSPS)(n) repeats. Evidence indicates that proteins that regulate the phosphorylation status of the CTD are determinants of growth, development, and stress responses of plants; however, little is known about the mechanisms that translate the CTD phosphoarray into physiological outputs. We report the bioinformatic identification of a family of three phospho-CTD-associated proteins (PCAPs) in Arabidopsis and the characterization of the AtPRP40 (Arabidopsis thaliana PRE-mRNA-PROCESSING PROTEIN 40) family as PCAPs. AtPRP40s-CTD/CTD-PO(4) interactions were confirmed using the yeast two-hybrid assay and far-Western blotting. WW domains at the N-terminus of AtPRP40b mediate the AtPRP40b-CTD/CTD-PO(4) interaction. Although AtPRP40s interact with both phosphorylated and unphosphorylated CTD in vitro, there is a strong preference for the phosphorylated form in Arabidopsis cell extract. AtPRP40s are ubiquitously expressed and localize to the nucleus. These results establish that AtPRP40s are specific PCAPs, which is consistent with the predicted function of the AtPRP40 family in pre-mRNA splicing.
authors.affiliation: Vegetable and Fruit Improvement Center, Department of Horticultural Sciences, Texas A&M University, College Station, TX 77843-2133, USA.
authors.forename: Chang Ho
authors.initials: CH
authors.lastname: Kang
authors.forename: Yue
authors.initials: Y
authors.lastname: Feng
authors.forename: Meenu
authors.initials: M
authors.lastname: Vikram
authors.forename: In Sil
authors.initials: IS
authors.lastname: Jeong
authors.forename: Jung Ro
authors.initials: JR
authors.lastname: Lee
authors.forename: Jeong Dong
authors.initials: JD
authors.lastname: Bahk
authors.forename: Dae-Jin
authors.initials: DJ
authors.lastname: Yun
authors.forename: Sang Yeol
authors.initials: SY
authors.lastname: Lee
authors.forename: Hisashi
authors.initials: H
authors.lastname: Koiwa
mesh_terms: D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D001483:Base Sequence; D026481:Blotting, Far-Western; D017931:DNA Primers; D011485:Protein Binding; D012319:RNA Polymerase II / Q000737:chemistry / Q000378:metabolism*; D012323:RNA Processing, Post-Transcriptional; D012326:RNA Splicing; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020798:Two-Hybrid System Techniques
chemical_list: D029681:Arabidopsis Proteins; D017931:DNA Primers; D012333:RNA, Messenger; D012319:RNA Polymerase II