Kat6b Modulates Oct4 and Nanog Binding to Chromatin in Embryonic Stem Cells and Is Required for Efficient Neural Differentiation

Abstract

Chromatin remodeling is fundamental for the dynamical changes in transcriptional programs that occur during development and stem cell differentiation. The histone acetyltransferase Kat6b is relevant for neurogenesis in mouse embryos and mutations of this gene cause intellectual disability in humans. However, the molecular mechanisms involved in Kat6b mutant phenotype and the role of this chromatin modifier in embryonic stem (ES) cells remain elusive. In this work, we show that Kat6b is expressed in ES cells and is repressed during differentiation. Moreover, we found that this gene is regulated by the pluripotency transcription factors (TFs) Nanog and Oct4. To study the functional relevance of Kat6b in ES cells, we generated a Kat6b knockout ES cell line (K6b-/-) using CRISPR/Cas9. Fluorescence correlation spectroscopy analyses suggest a more compact chromatin organization in K6b-/cells and impaired interactions of Oct4 and Nanog with chromatin. Remarkably, K6b-/-cells showed a reduced efficiency to differentiate to neural lineage. These results reveal a role of Kat6b as a modulator of chromatin plasticity, its impact on chromatin-TFs interactions and its influence on cell fate decisions during neural development.

Dynamical reorganization of the pluripotency transcription factors Oct4 and Sox2 during early differentiation of embryonic stem cells

“…Additionally, the method has the advantage of requiring relatively low levels of fluorescent proteins minimally modifying the cell homeostasis. We have recently used this powerful tool to explore how certain epigenetic modifications in ES cells modulate Oct4 and Nanog interactions with chromatin 36 .…”

“…Figure 3a,b show the mean, normalized autocorrelation functions (ACF) obtained for Oct4-YPet and Sox2-YPet in undifferentiated and early-differentiated ES cells. The ACF curves could be interpreted with a model that includes the diffusion of the proteins and their interactions with chromatin targets in two distinct temporal windows 15,18,36 . The fitting of the model to the experimental data provides relevant information on how TFs distribute within the nuclear space.…”

Network and Evolutionary Analysis of Human Epigenetic Regulators to Unravel Disease Associations

“…Of the 55 Seed-DDEN genes in the turquoise module, 7 ER genes (RAI1, KAT6B, NSD2, BAZ1B, SRCAP, ADNP, and HUWE1) were found to be positively selected ( Table 1). Most of them were implicated in the transcriptional regulation of multicellular development including DNA damage responses [64,65] and neural differentiation [66,67]. Therefore, while these ER genes appear to confer fitness advantages to humans during some stages of life history, they could also specifically increase the risk of various developmental diseases through the dysregulation of the turquoise module at the stages of multicellular development [68,69].…”

Tyroxine Hydroxylase-Positive Neuronal Cell Population is Increased by Temporal Dioxin Exposure at Early Stage of Differentiation from Human Embryonic Stem Cells

“…Otherwise, human transcription factors for the activation of these genes may have insufficient activity for these rat promoters. Rather than simple transfection, it is necessary to use human TH -promoter DNA with knockin vector or the gene editing technology [61].…”