title: Threonine-4 of mammalian RNA polymerase II CTD is targeted by Polo-like kinase 3 and required for transcriptional elongation.
abstract: Eukaryotic RNA polymerase II (Pol II) has evolved an array of heptad repeats with the consensus sequence Tyr1-Ser2-Pro3-Thr4-Ser5-Pro6-Ser7 at the carboxy-terminal domain (CTD) of the large subunit (Rpb1). Differential phosphorylation of Ser2, Ser5, and Ser7 in the 5' and 3' regions of genes coordinates the binding of transcription and RNA processing factors to the initiating and elongating polymerase complexes. Here, we report phosphorylation of Thr4 by Polo-like kinase 3 in mammalian cells. ChIPseq analyses indicate an increase of Thr4-P levels in the 3' region of genes occurring subsequently to an increase of Ser2-P levels. A Thr4/Ala mutant of Pol II displays a lethal phenotype. This mutant reveals a global defect in RNA elongation, while initiation is largely unaffected. Since Thr4 replacement mutants are viable in yeast we conclude that this amino acid has evolved an essential function(s) in the CTD of Pol II for gene transcription in mammalian cells.
authors.affiliation: Department of Molecular Epigenetics, Helmholtz Center Munich, Center of Integrated Protein Science, Germany.
authors.forename: Corinna
authors.initials: C
authors.lastname: Hintermair
authors.forename: Martin
authors.initials: M
authors.lastname: Heidemann
authors.forename: Frederic
authors.initials: F
authors.lastname: Koch
authors.forename: Nicolas
authors.initials: N
authors.lastname: Descostes
authors.forename: Marta
authors.initials: M
authors.lastname: Gut
authors.forename: Ivo
authors.initials: I
authors.lastname: Gut
authors.forename: Romain
authors.initials: R
authors.lastname: Fenouil
authors.forename: Pierre
authors.initials: P
authors.lastname: Ferrier
authors.forename: Andrew
authors.initials: A
authors.lastname: Flatley
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Kremmer
authors.forename: Rob D
authors.initials: RD
authors.lastname: Chapman
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Andrau
authors.forename: Dirk
authors.initials: D
authors.lastname: Eick
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D002460:Cell Line; D047369:Chromatin Immunoprecipitation; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D020043:Genes, Essential; D006801:Humans; D016297:Mutagenesis, Site-Directed; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D012319:RNA Polymerase II / Q000235:genetics / Q000378:metabolism*; D013912:Threonine / Q000378:metabolism*; D014158:Transcription, Genetic; D025521:Tumor Suppressor Proteins; D000097868:Polo-like Kinases
chemical_list: D017346:Protein Serine-Threonine Kinases; D012319:RNA Polymerase II; D013912:Threonine; D025521:Tumor Suppressor Proteins; C486256:PLK3 protein, human; D000097868:Polo-like Kinases