Arabidopsis thaliana PRP40s are RNA polymerase II C-terminal domain-associating proteins.
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.
Kang
Chang Ho
CH
Vegetable and Fruit Improvement Center, Department of Horticultural Sciences, Texas A&M University, College Station, TX 77843-2133, USA.
Feng
Yue
Y
Vikram
Meenu
M
Jeong
In Sil
IS
Lee
Jung Ro
JR
Bahk
Jeong Dong
JD
Yun
Dae-Jin
DJ
Lee
Sang Yeol
SY
Koiwa
Hisashi
H
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
D029681:Arabidopsis Proteins; D017931:DNA Primers; D012333:RNA, Messenger; D012319:RNA Polymerase II