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Embryonic Stem Cells/Induced Pluripotent Stem Cells
Article first published online: 9 OCT 2009
Copyright © 2009 AlphaMed Press
Volume 27, Issue 12, pages 3001–3011, December 2009
How to Cite
Ponnusamy, M. P., Deb, S., Dey, P., Chakraborty, S., Rachagani, S., Senapati, S. and Batra, S. K. (2009), RNA Polymerase II Associated Factor 1/PD2 Maintains Self-Renewal by Its Interaction with Oct3/4 in Mouse Embryonic Stem Cells. STEM CELLS, 27: 3001–3011. doi: 10.1002/stem.237
Author contributions: M.P.P.: conception and design, collection and/or assembly of data, data analysis and interpretation, manuscript writing; S.D.: ESC knockout design, data analysis, manuscript writing; P.D.: data analysis, manuscript writing; S.C. and S.S.: data analysis, manuscript writing; S.R.: real-time PCR and its data analysis; S.K.B.: conception and design, financial support, data analysis and interpretation, manuscript writing, final approval of manuscript.
First published online in STEM CELLS EXPRESS October 9, 2009.
Disclosure of potential conflicts of interest is found at the end of this article.
- Issue published online: 14 DEC 2009
- Article first published online: 9 OCT 2009
- Accepted manuscript online: 9 OCT 2009 12:00AM EST
- Manuscript Accepted: 5 OCT 2009
- Manuscript Received: 14 JUL 2009
- National Institutes of Health. Grant Numbers: CA78590, CA131944, 133774
- Department of Defense. Grant Number: BC061220
- PAF complex;
- Embryonic stem cells
Embryonic stem cells (ESCs) maintain self-renewal while ensuring a rapid response to differentiation signals, but the exact mechanism of this process remains unknown. PD2 is the human homolog of the RNA polymerase II-associated factor 1 (Paf1). The Paf1/PD2 is a member of the human PAF complex that consists of four other subunits, hCdc73, hLeo1, hCtr9, and hSki8, and is involved in the regulation of transcriptional elongation and further downstream events. Here, we show that Paf1/PD2 is overexpressed in mouse ESCs and is involved in the maintenance of mouse ESCs. The Paf1/PD2 knockdown and knockout ESCs grown under self-renewal conditions express substantially reduced levels of self-renewal regulators, including Oct3/4, SOX2, Nanog, and Shh. We observed that the level of Paf1/PD2 expression is much higher in self-renewing mouse embryonic carcinoma cells than in the differentiating cells. Knockout of Paf1/PD2 altered ESC phenotype by increasing apoptosis and decreasing the percentage of cells in S-phase of the cell cycle. Interestingly, we found that the key genes that regulate endodermal differentiation (Gata4, Gata6, and Fgf8) are induced in the Paf1/PD2 heterozygous knockout ESCs. This suggests that Paf1/PD2 plays a specific role in regulating early commitment of ESCs to endodermal differentiation. Furthermore, for the first time, we showed that Paf1/PD2 protein interacts with Oct3/4 and RNA polymerase II, and through this interaction Paf1/PD2 may regulate Oct3/4-mediated gene expression. Thus, the Paf1/PD2 protein is a newly discovered element of the interconnected regulatory network that maintains the self-renewal of mouse ESCs. STEM CELLS 2009;27:3001–3011