About the Authors

Jessica L. Dermody

Affiliation Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, United States of America

Jonathan M. Dreyfuss

Affiliation Harvard-Partners Center for Genetics and Genomics, Boston, Massachusetts, United States of America

Judit Villén

Affiliation Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, United States of America

Babatunde Ogundipe

Affiliation Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America

Steven P. Gygi

Affiliation Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, United States of America

Peter J. Park

Affiliation Harvard-Partners Center for Genetics and Genomics, Boston, Massachusetts, United States of America

Alfred S. Ponticelli

Affiliation Department of Biochemistry, School of Medicine and Biomedical Sciences, State University of New York, Buffalo, New York, United States of America

Claire L. Moore

Affiliation Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America

Stephen Buratowski

Affiliation Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, United States of America

Miriam E. Bucheli

Miriam_Bucheli@hms.harvard.edu

Affiliation Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, United States of America

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: MEB. Performed the experiments: JLD JV BO MEB. Analyzed the data: JLD JD JV MEB. Contributed reagents/materials/analysis tools: JD JV SPG PJP ASP CM SB MEB. Wrote the paper: JLD MEB. Figures 2 & 4: JLD. Oligo(dC)-tail template elongation assay: JLD. Figure 5, Expression analysis: JD PJP. Figure S2, S3 and S4, Expression analysis: JD PJP. Figure S1: JV SPG. Mass spectrometry analysis of Cka1 phosphorylation specificity using peptide libraries: JV. Analysis of Npl3 phosphorylation sites: JV. Editing of paper: JV. Figure 3: BO. Cka1 phosphorylation in vitro analysis: BO. Cka1 phosphorylation in vivo analysis: BO. Mass spectrometry analysis of Cka1 phosphorylation specificity using peptide libraries: SPG. Analysis of Npl3 phosphorylation sites: SPG. Figure 2: ASP. RNAP II purification: ASP. Editing of paper and guidance: CM SB.