Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Química Biológica (IQUIBICEN), Buenos Aires, Argentina.
CONICET-Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia (FLENI), Laboratorio de Investigación de Aplicación a Neurociencias (LIAN), Buenos Aires, Argentina.
J Mol Biol. 2019 Mar 15;431(6):1148-1159. doi: 10.1016/j.jmb.2019.02.012. Epub 2019 Feb 18.
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 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-transcription factors interactions and its influence on cell fate decisions during neural development.
染色质重塑对于发育和干细胞分化过程中转录程序的动态变化至关重要。组蛋白乙酰转移酶 Kat6b 与小鼠胚胎中的神经发生有关，该基因的突变会导致人类智力障碍。然而，Kat6b 突变表型涉及的分子机制以及这种染色质修饰物在胚胎干细胞（ES 细胞）中的作用仍不清楚。在这项工作中，我们表明 Kat6b 在 ES 细胞中表达，并在分化过程中受到抑制。此外，我们发现该基因受多能转录因子 Nanog 和 Oct4 调控。为了研究 Kat6b 在 ES 细胞中的功能相关性，我们使用 CRISPR/Cas9 生成了 Kat6b 敲除 ES 细胞系（K6b-/-）。荧光相关光谱分析表明，K6b-/-细胞中的染色质组织更为紧凑，Oct4 和 Nanog 与染色质的相互作用受损。值得注意的是，K6b-/-细胞向神经谱系分化的效率降低。这些结果揭示了 Kat6b 作为染色质可塑性调节剂的作用，其对染色质-转录因子相互作用的影响以及其对神经发育过程中细胞命运决定的影响。
