Distinct Roles for CBP and p300 on the RA-Mediated Expression of the Meiosis Commitment Gene Stra8 in Mouse Embryonic Stem Cells

Abstract

In mammalian germ cells, meiotic commitment requires the expression of Stimulated by retinoic acid gene 8 (Stra8), which is transcriptionally activated by retinoic acid (RA). However, little is known about the epigenetic mechanism by which RA induces Stra8 expression. Utilizing a chromatin immunoprecipitation assay (ChIP), we showed that RA increases histone acetylation at the Stra8 promoter in murine embryonic stem cells (ESCs), a model for germ cell differentiation. Furthermore, we explored whether two coregulators with histone acetyltransferase (HAT) activity, Creb-binding protein (CBP) and p300, are involved in the activation of Stra8. The lentiviral shRNA knockdown of endogenous CBP led to Stra8 repression, while the overexpression of CBP enhanced Stra8 expression at both the mRNA and protein levels. ChIP analysis confirmed that CBP is the crucial coactivator for RA-mediated Stra8 transcription and that it enhances the level of histone acetylation and recruits RNA polymerase II to establish transcriptionally active chromatin. Furthermore, shRNA of p300 enhanced Stra8 expression, and the overexpression of p300 reduced Stra8 expression, independently of its HAT activity. ChIP showed that the knockdown of p300 significantly increased the level of CBP at the Stra8 promoter. These findings demonstrate that CBP and p300 play distinct roles in RA-mediated Stra8 gene transcription.

Differentiation of Mouse Embryonic Stem Cells toward Functional Pancreatic β-Cell Surrogates through Epigenetic Regulation ofPdx1by Nitric Oxide

“…Moreover, pull-down experiments with JARID-2 and EZH2 show that P300 interacts with PRC2 complex in undifferentiated conditions. These results are in agreement with those from previous studies that showed that P300 can act as a repressor independently of its acetyltransferase activity 25,26,42,43 . Possible posttranslational modifications such as a SUMO-dependent repression 25 or recruitment of other repressive components such as HDAC6 or HDAC1 26 remain to be studied.…”

Variant PRC1 competes with retinoic acid-related signals to repress Meis2 in distal forelimb bud

“…1A, tracks 5, 6). These findings suggest that RA-related signals upregulate Meis2 expression via activation of an RAR/coactivator pathway in the proximal forelimb bud (Bajpe et al, 2013;Chen et al, 2013;Jin et al, 2011).…”

MiR-630 inhibits proliferation by targeting CDC7 kinase, but maintains the apoptotic balance by targeting multiple modulators in human lung cancer A549 cells

“…Furthermore, miR-630 mimic significantly decreased the expression of DDIT4, PARP3 and EP300 mRNA ( Figure 5d , upper panel) and of protein ( Figure 5e , left panel) in A549 cells, whereas anti-miR-630 increased their mRNA ( Figure 5d , lower panel) and protein ( Figure 5e , right panel) compared with scrambled siRNA, indicating DDIT4, PARP3 and EP300 as targets for miR-630. Next, we performed individual and combined silencing of three molecules in A549 by specific siRNA oligonucleotides 41 , 42 (also see http: // www.pnas.org/cgi/content/short/1016574108 ) to examine the effects of targeting DDIT4, PARP3 and EP300 by miR-630 on CIS-induced apoptosis. Compared with scrambled siRNA-transfected A549, where CIS exposure induced ~25.2% early apoptosis, silencing DDIT4, PARP3 or EP300 reduced 4.1% ( P =0.0435), 2.9% ( P =0.0476) and 6.8% ( P =0.0363) apoptosis, respectively; in particular, combined silencing of them reduced 10.7% apoptosis ( P =0.0085) ( Figures 5f and g and Supplementary Figure S8 ).…”