MOE Key Laboratory for Cellular Dynamics, Hefei National Center for Cross-disciplinary Sciences, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, P. R. China.
Department of Neurosurgery, University of Minnesota, Minneapolis, Minnesota, USA.
J Biol Chem. 2022 Dec;298(12):102607. doi: 10.1016/j.jbc.2022.102607. Epub 2022 Oct 17.
The Spalt-like 4 transcription factor (SALL4) plays an essential role in controlling the pluripotent property of embryonic stem cells via binding to AT-rich regions of genomic DNA, but structural details on this binding interaction have not been fully characterized. Here, we present crystal structures of the zinc finger cluster 4 (ZFC4) domain of SALL4 (SALL4) bound with different dsDNAs containing a conserved AT-rich motif. In the structures, two zinc fingers of SALL4 recognize an AATA tetranucleotide. We also solved the DNA-bound structures of SALL3 and SALL4. These structures illuminate a common preference for the AATA tetranucleotide shared by ZFC4 of SALL1, SALL3, and SALL4. Furthermore, our cell biology experiments demonstrate that the DNA-binding activity is essential for SALL4 function as DNA-binding defective mutants of mouse Sall4 failed to repress aberrant gene expression in Sall4-/- mESCs. Thus, these analyses provide new insights into the mechanisms of action underlying SALL family proteins in controlling cell fate via preferential targeting to AT-rich sites within genomic DNA during cell differentiation.
Spalt 样转录因子 4（SALL4）通过与基因组 DNA 的富含 AT 区域结合，在控制胚胎干细胞的多能性方面发挥着重要作用，但这种结合相互作用的结构细节尚未完全表征。在这里，我们展示了 SALL4（SALL4）的锌指簇 4（ZFC4）结构域与包含保守富含 AT 基序的不同 dsDNA 结合的晶体结构。在这些结构中，SALL4 的两个锌指识别一个 AATA 四核苷酸。我们还解决了 SALL3 和 SALL4 的 DNA 结合结构。这些结构阐明了 SALL1、SALL3 和 SALL4 的 ZFC4 共同具有的对 AATA 四核苷酸的共同偏好。此外，我们的细胞生物学实验表明，DNA 结合活性对于 SALL4 功能至关重要，因为小鼠 Sall4 的 DNA 结合缺陷突变体未能抑制 Sall4-/- mESCs 中异常基因表达的抑制。因此，这些分析为 SALL 家族蛋白通过在细胞分化过程中优先靶向基因组 DNA 中的富含 AT 区域来控制细胞命运的作用机制提供了新的见解。
