TFAP2 基因家族成员促进 MITF 在色素沉着和细胞增殖基因中对染色质的可及性。

TFAP2 paralogs facilitate chromatin access for MITF at pigmentation and cell proliferation genes.

机构信息

Department of Anatomy and Cell Biology, College of Medicine, University of Iowa, Iowa City, Iowa, United States of America.

Department of Biochemistry and Molecular Biology, BioMedical Center, Faculty of Medicine, University of Iceland, Reykjavik, Iceland.

出版信息

PLoS Genet. 2022 May 17;18(5):e1010207. doi: 10.1371/journal.pgen.1010207. eCollection 2022 May.

Abstract

In developing melanocytes and in melanoma cells, multiple paralogs of the Activating-enhancer-binding Protein 2 family of transcription factors (TFAP2) contribute to expression of genes encoding pigmentation regulators, but their interaction with Microphthalmia transcription factor (MITF), a master regulator of these cells, is unclear. Supporting the model that TFAP2 facilitates MITF's ability to activate expression of pigmentation genes, single-cell seq analysis of zebrafish embryos revealed that pigmentation genes are only expressed in the subset of mitfa-expressing cells that also express tfap2 paralogs. To test this model in SK-MEL-28 melanoma cells we deleted the two TFAP2 paralogs with highest expression, TFAP2A and TFAP2C, creating TFAP2 knockout (TFAP2-KO) cells. We then assessed gene expression, chromatin accessibility, binding of TFAP2A and of MITF, and the chromatin marks H3K27Ac and H3K27Me3 which are characteristic of active enhancers and silenced chromatin, respectively. Integrated analyses of these datasets indicate TFAP2 paralogs directly activate enhancers near genes enriched for roles in pigmentation and proliferation, and directly repress enhancers near genes enriched for roles in cell adhesion. Consistently, compared to WT cells, TFAP2-KO cells proliferate less and adhere to one another more. TFAP2 paralogs and MITF co-operatively activate a subset of enhancers, with the former necessary for MITF binding and chromatin accessibility. By contrast, TFAP2 paralogs and MITF do not appear to co-operatively inhibit enhancers. These studies reveal a mechanism by which TFAP2 profoundly influences the set of genes activated by MITF, and thereby the phenotype of pigment cells and melanoma cells.

摘要

在黑色素细胞和黑色素瘤细胞的发育过程中,激活增强子结合蛋白 2 家族的多个基因家族的转录因子(TFAP2)多基因家族有助于表达编码色素沉着调节剂的基因,但它们与小眼畸形转录因子(MITF)的相互作用,这些细胞的主要调节剂,尚不清楚。支持 TFAP2 有助于 MITF 激活色素基因表达的能力的模型,斑马鱼胚胎的单细胞序列分析显示,只有在表达 mitfa 的细胞亚群中才表达色素基因,该亚群也表达 tfap2 基因家族。为了在 SK-MEL-28 黑色素瘤细胞中验证该模型,我们删除了表达量最高的两个 TFAP2 基因家族,TFAP2A 和 TFAP2C,从而创建了 TFAP2 敲除(TFAP2-KO)细胞。然后,我们评估了基因表达、染色质可及性、TFAP2A 和 MITF 的结合以及染色质标记 H3K27Ac 和 H3K27Me3,它们分别是活跃增强子和沉默染色质的特征。对这些数据集的综合分析表明,TFAP2 基因家族直接激活了富含色素沉着和增殖作用的基因附近的增强子,直接抑制了富含细胞粘附作用的基因附近的增强子。一致地,与 WT 细胞相比,TFAP2-KO 细胞增殖较少,彼此之间的粘附更多。TFAP2 基因家族和 MITF 合作激活了一组增强子,前者是 MITF 结合和染色质可及性所必需的。相比之下,TFAP2 基因家族和 MITF 似乎没有合作抑制增强子。这些研究揭示了 TFAP2 深刻影响 MITF 激活的基因集合的机制,从而影响色素细胞和黑色素瘤细胞的表型。

https://cdn.ncbi.nlm.nih.gov/pmc/blobs/c7ba/9159589/8e78ecc34605/pgen.1010207.g001.jpg

文献AI研究员

20分钟写一篇综述,助力文献阅读效率提升50倍

立即体验

用中文搜PubMed

大模型驱动的PubMed中文搜索引擎

马上搜索