Unphosphorylated SR-like protein Npl3 stimulates RNA polymerase II elongation.
The production of a functional mRNA is regulated at every step of transcription. An area not well-understood is the transition of RNA polymerase II from elongation to termination. The S. cerevisiae SR-like protein Npl3 functions to negatively regulate transcription termination by antagonizing the binding of polyA/termination proteins to the mRNA. In this study, Npl3 is shown to interact with the CTD and have a direct stimulatory effect on the elongation activity of the polymerase. The interaction is inhibited by phosphorylation of Npl3. In addition, Casein Kinase 2 was found to be required for the phosphorylation of Npl3 and affect its ability to compete against Rna15 (Cleavage Factor I) for binding to polyA signals. Our results suggest that phosphorylation of Npl3 promotes its dissociation from the mRNA/RNAP II, and contributes to the association of the polyA/termination factor Rna15. This work defines a novel role for Npl3 in elongation and its regulation by phosphorylation.
Dermody
Jessica L
JL
Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA.
Dreyfuss
Jonathan M
JM
Villén
Judit
J
Ogundipe
Babatunde
B
Gygi
Steven P
SP
Park
Peter J
PJ
Ponticelli
Alfred S
AS
Moore
Claire L
CL
Buratowski
Stephen
S
Bucheli
Miriam E
ME
D001667:Binding, Competitive; D047390:Casein Kinase II / Q000378:metabolism; D020134:Catalytic Domain; D015966:Gene Expression Regulation, Fungal; D008954:Models, Biological; D009687:Nuclear Proteins / Q000378:metabolism*; D010766:Phosphorylation; D011061:Poly A / Q000737:chemistry; D017434:Protein Structure, Tertiary; D012319:RNA Polymerase II / Q000737:chemistry*; D012333:RNA, Messenger / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D014158:Transcription, Genetic; D039221:mRNA Cleavage and Polyadenylation Factors / Q000378:metabolism
C077734:NPL3 protein, S cerevisiae; D009687:Nuclear Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins; D039221:mRNA Cleavage and Polyadenylation Factors; C512635:RNA15 protein, S cerevisiae; D011061:Poly A; D047390:Casein Kinase II; D012319:RNA Polymerase II