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Casein kinase 2 inhibits HomolD‐directed transcription by Rrn7 in Schizosaccharomyces pombe
Author(s) -
MoreiraRamos Sandra,
Rojas Diego A.,
Montes Matías,
Urbina Fabiola,
Miralles Vicente J.,
Maldonado Edio
Publication year - 2015
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/febs.13157
Subject(s) - rna polymerase ii , ribosome biogenesis , biology , general transcription factor , schizosaccharomyces pombe , transcription factor ii d , transcription (linguistics) , casein kinase 2 , casein kinase 1 , microbiology and biotechnology , promoter , protein kinase a , ribosome , cyclin dependent kinase 2 , phosphorylation , gene , biochemistry , gene expression , rna , mutant , linguistics , philosophy
In Schizosaccharomyces pombe , ribosomal protein gene ( RPG ) promoters contain a TATA analogue element called the HomolD box. The HomolD‐binding protein Rrn7 forms a complex with the RNA polymerase II machinery. Despite the importance of ribosome biogenesis to cell survival, the mechanisms involved in the regulation of transcription of eukaryotic RPG s are unknown. In this study, we identified Rrn7 as a new substrate of the pleiotropic casein kinase 2 ( CK 2), which is a regulator of basal transcription. Recombinant Rrn7 from S. pombe , which is often used as a model organism for studying eukaryotic transcription, interacted with CK 2 in vitro and in vivo . Furthermore, CK 2‐mediated phosphorylation of Rrn7 inhibited its HomolD‐directed transcriptional activity and ability to bind to an oligonucleotide containing a HomolD box in vitro . Mutation of Rrn7 at Thr67 abolished these effects, indicating that this residue is a critical CK 2 phosphorylation site. Finally, Rrn7 interacted with the regulatory subunit of CK 2 in vivo , inhibition of CK 2 in vivo potentiated ribosomal protein gene transcription, and chromatin immunoprecipitation analyses identified that the catalytic subunit of CK 2 was associated with the rpk5 gene promoter in S. pombe . Taken together, these data suggest that CK 2 inhibits ribosomal protein gene transcription in S. pombe via phosphorylation of Rrn7 at Thr67.