Department of Molecular, Cellular and Developmental Biology, Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA.
Center for Stem Cell Biology and Engineering, University of California, Santa Barbara, CA 93106, USA.
Cells. 2024 Jul 13;13(14):1189. doi: 10.3390/cells13141189.
The chromatin-associated protein WDR5 has been widely studied due to its role in histone modification and its potential as a pharmacological target for the treatment of cancer. In humans, the protein with highest sequence homology to WDR5 is encoded by the retrogene WDR5B, which remains unexplored. Here, we used CRISPR-Cas9 genome editing to generate WDR5B knockout and WDR5B-FLAG knock-in cell lines for further characterization. In contrast to WDR5, WDR5B exhibits low expression in pluripotent cells and is upregulated upon neural differentiation. Loss or shRNA depletion of WDR5B impairs cell growth and increases the fraction of non-viable cells in proliferating retinal pigment epithelial (RPE) cultures. CUT&RUN chromatin profiling in RPE and neural progenitors indicates minimal WDR5B enrichment at established WDR5 binding sites. These results suggest that WDR5 and WDR5B exhibit several divergent biological properties despite sharing a high degree of sequence homology.
由于其在组蛋白修饰中的作用及其作为癌症治疗的药理学靶点的潜力，染色质相关蛋白 WDR5 已被广泛研究。在人类中，与 WDR5 具有最高序列同源性的蛋白质由反基因 WDR5B 编码，而 WDR5B 尚未被探索。在这里，我们使用 CRISPR-Cas9 基因组编辑生成 WDR5B 敲除和 WDR5B-FLAG 敲入细胞系以进一步表征。与 WDR5 相比，WDR5B 在多能细胞中的表达水平较低，并且在神经分化时上调。WDR5B 的缺失或 shRNA 耗尽会损害细胞生长并增加增殖性视网膜色素上皮 (RPE) 培养物中不可存活细胞的比例。在 RPE 和神经祖细胞中的 CUT&RUN 染色质分析表明，在已建立的 WDR5 结合位点处 WDR5B 的富集程度最小。这些结果表明，尽管 WDR5 和 WDR5B 具有高度的序列同源性，但它们表现出几种不同的生物学特性。
