FCP1 phosphorylation by casein kinase 2 enhances binding to TFIIF and RNA polymerase II carboxyl-terminal domain phosphatase activity.
Dephosphorylation of RNA polymerase II carboxyl-terminal domain (CTD) is required to resume sequential transcription cycles. FCP1 (TFIIF-dependent CTD phosphatase 1) is the only known phosphatase targeting RNAP II CTD. Here we show that in Xenopus laevis cells, xFCP1 is a phosphoprotein. On the basis of biochemical fractionation and drug sensitivity, casein kinase 2 (CK2) is shown to be the major kinase involved in xFCP1 phosphorylation in X. laevis egg extracts. CK2 phosphorylates xFCP1 mainly at a cluster of serines centered on Ser(457). CK2-dependent phosphorylation enhances 4-fold the CTD phosphatase activity of FCP1 and its binding to the RAP74 subunit of general transcription factor TFIIF. These findings unravel a new mechanism regulating CTD phosphorylation and hence class II gene transcription.
UMR 8541 CNRS, Génétique Moléculaire, Ecole Normale Supérieure, 46 rue d'Ulm, 75230 Paris Cedex 05, France.
Benoît
B
Palancade
Marie-Françoise
MF
Dubois
Olivier
O
Bensaude
D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D047390:Casein Kinase II; D002845:Chromatography; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D015971:Gene Expression Regulation, Enzymologic; D005978:Glutathione / Q000378:metabolism; D008969:Molecular Sequence Data; D010749:Phosphoprotein Phosphatases / Q000737:chemistry / Q000378:metabolism*; D010750:Phosphoproteins / Q000737:chemistry; D010766:Phosphorylation; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D011485:Protein Binding; D054645:Protein Phosphatase 1; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D012319:RNA Polymerase II / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D012685:Sepharose / Q000378:metabolism; D012694:Serine / Q000378:metabolism; D013997:Time Factors; D019473:Transcription Factors, TFII / Q000737:chemistry / Q000378:metabolism*; D014158:Transcription, Genetic; D014981:Xenopus; D014982:Xenopus laevis
D010750:Phosphoproteins; D011994:Recombinant Proteins; D019473:Transcription Factors, TFII; D012694:Serine; D012685:Sepharose; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases; D012319:RNA Polymerase II; D010749:Phosphoprotein Phosphatases; D054645:Protein Phosphatase 1; C116022:carboxy-terminal domain phosphatase; C056604:transcription factor TFIIF; D005978:Glutathione