title: Involvement of phosphatidylinositol 4,5-bisphosphate in RNA polymerase I transcription.
abstract: RNA polymerase I (Pol I) transcription is essential for the cell cycle, growth and protein synthesis in eukaryotes. In the present study, we found that phosphatidylinositol 4,5-bisphosphate (PIP2) is a part of the protein complex on the active ribosomal promoter during transcription. PIP2 makes a complex with Pol I and the Pol I transcription factor UBF in the nucleolus. PIP2 depletion reduces Pol I transcription, which can be rescued by the addition of exogenous PIP2. In addition, PIP2 also binds directly to the pre-rRNA processing factor fibrillarin (Fib), and co-localizes with nascent transcripts in the nucleolus. PIP2 binding to UBF and Fib modulates their binding to DNA and RNA, respectively. In conclusion, PIP2 interacts with a subset of Pol I transcription machinery, and promotes Pol I transcription.
authors.affiliation: Laboratory of Biology of the Cell Nucleus, Institute of Molecular Genetics ASCR, v.v.i., Vídeňská 1083, 142 20, Prague 4, Czech Republic.
authors.forename: Sukriye
authors.initials: S
authors.lastname: Yildirim
authors.forename: Enrique
authors.initials: E
authors.lastname: Castano
authors.forename: Margarita
authors.initials: M
authors.lastname: Sobol
authors.forename: Vlada V
authors.initials: VV
authors.lastname: Philimonenko
authors.forename: Rastislav
authors.initials: R
authors.lastname: Dzijak
authors.forename: Tomás
authors.initials: T
authors.lastname: Venit
authors.forename: Pavel
authors.initials: P
authors.lastname: Hozák
mesh_terms: D045744:Cell Line, Tumor; D002466:Cell Nucleolus / Q000235:genetics / Q000378:metabolism; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000235:genetics* / Q000378:metabolism*; D035463:Pol1 Transcription Initiation Complex Proteins / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D012318:RNA Polymerase I / Q000235:genetics* / Q000378:metabolism*; D012322:RNA Precursors / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000235:genetics*
chemical_list: D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D019269:Phosphatidylinositol 4,5-Diphosphate; D035463:Pol1 Transcription Initiation Complex Proteins; D012322:RNA Precursors; C047458:fibrillarin; C063844:transcription factor UBF; D012318:RNA Polymerase I
keywords: Fibrillarin; Nucleolus; PIP2; Transcription; UBF