LIN9, a Subunit of the DREAM Complex, Regulates Mitotic Gene Expression and Proliferation of Embryonic Stem Cells

Jasmina Esterlechner,Stefan Gaubatz,Florian Finkernagel,Nina Reichert,Michael Krause,Fabian Iltzsche,Austin John Cooney

doi:10.1371/journal.pone.0062882

Jasmina Esterlechner, Stefan Gaubatz + Show 5 more

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https://doi.org/10.1371/journal.pone.0062882

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Journal: PLoS ONE	Publication Date: May 7, 2013
Citations: 49	License type: CC BY 4.0

Affiliation: University of Würzburg, Philipps University of Marburg

Abstract

The DREAM complex plays an important role in regulation of gene expression during the cell cycle. We have previously shown that the DREAM subunit LIN9 is required for early embryonic development and for the maintenance of the inner cell mass in vitro. In this study we examined the effect of knocking down LIN9 on ESCs. We demonstrate that depletion of LIN9 alters the cell cycle distribution of ESCs and results in an accumulation of cells in G2 and M and in an increase of polyploid cells. Genome-wide expression studies showed that the depletion of LIN9 results in downregulation of mitotic genes and in upregulation of differentiation-specific genes. ChIP-on chip experiments showed that mitotic genes are direct targets of LIN9 while lineage specific markers are regulated indirectly. Importantly, depletion of LIN9 does not alter the expression of pluripotency markers SOX2, OCT4 and Nanog and LIN9 depleted ESCs retain alkaline phosphatase activity. We conclude that LIN9 is essential for proliferation and genome stability of ESCs by activating genes with important functions in mitosis and cytokinesis.

Highlights

Pluripotent embryonic stem cells (ESCs) are derived from the inner cell mass (ICM) of the pre-implantation embryo
LIN9 is a Component of the DREAM Complex in ESCs We investigated the expression of LIN9 in ESCs, which are derived from the inner cell mass of pre-implantation blastocysts
We describe the first genome-wide analysis of genes regulated by the DREAM-subunit LIN9 in murine ESCs by using a combination of RNAi mediated depletion of LIN9 and microarray experiments

Summary

Introduction

Pluripotent embryonic stem cells (ESCs) are derived from the inner cell mass (ICM) of the pre-implantation embryo. ESCs have the unique ability to self-renew while retaining the ability to differentiate into any cell type of the adult animal. Self-renewal and pluripotency of ESCs is maintained by a set of pluripotency transcription factors such as SOX2, OCT4 and Nanog and by polycomb group complexes that maintain the undifferentiated state of ESCs through the repression of developmental genes [1]. Inactivation of pluripotency factors or polycomb proteins leads to loss of pluripotent cells and aberrant differentiation. Embryonic stem cells are characterized by an unusual cell cycle. The abnormal cell cycle structure of ESCs is intimately linked to the unique features of ESCs. the relationship between cell cycle regulation and ESC pluripotency is incompletely understood. While it has been suggested that the short G1 phase of ESCs inhibits their differentiation and preserves pluripotency, a recent study showed that a short G1 phase is not sufficient to prevent differentiation of ESCs [4]

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