Involvement of phosphatidylinositol 4,5-bisphosphate in RNA polymerase I transcription

• Published in: Journal of cell science Vol. 126; no. Pt 12; pp. 2730 - 2739
• Main Authors: Yildirim, Sukriye, Castano, Enrique, Sobol, Margarita, Philimonenko, Vlada V, Dzijak, Rastislav, Venit, Tomás, Hozák, Pavel
• Format: Journal Article
• Language: English
• Published: England 15-06-2013
• Subjects: Cell Line, Tumor; Cell Nucleolus - genetics; Cell Nucleolus - metabolism; Chromosomal Proteins, Non-Histone - genetics; Chromosomal Proteins, Non-Histone - metabolism; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; HeLa Cells; Humans; Phosphatidylinositol 4,5-Diphosphate - genetics; Phosphatidylinositol 4,5-Diphosphate - metabolism; Pol1 Transcription Initiation Complex Proteins - genetics; Pol1 Transcription Initiation Complex Proteins - metabolism; Promoter Regions, Genetic - genetics; RNA Polymerase I - genetics; RNA Polymerase I - metabolism; RNA Precursors - genetics; RNA Precursors - metabolism; Transcription, Genetic - genetics; UBF; Nucleolus; Transcription; Fibrillarin; PIP2
• ISSN: 0021-9533; 1477-9137
• DOI: 10.1242/jcs.123661

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.