Dual Regulatory Functions of Classical Zinc Finger Clusters from Myeloid Zinc Finger‐1

Zinc finger (ZF) proteins constitute a large family of transcriptional regulators that control gene expression through sequence‐specific DNA recognition stabilized by Zn 2+ ‐coordination. Myeloid zinc finger‐1 (MZF1) is a classical ZF protein associated with diverse gene regulation, although the biochemical basis of its promoter recognition remains unclear. MZF1 contains 13 CX 2 CX 12 HX 3 H‐type ZF domains organized into two discrete clusters, MZF1(ZF1–4) and MZF1(ZF5–13), suggesting the modular regulation of distinct binding partners. In this study, we investigate the metal‐binding properties and promoter recognition behavior of these ZF clusters in MZF1. Spectroscopic studies reveal that MZF1(ZF1–4) exhibits stable Zn 2+ ‐coordination with strong resistance to cysteine oxidation, whereas Zn 2+ removal from MZF1(ZF5–13) induces rapid oxidation. Fluorescence anisotropy assays show that both ZF clusters of MZF1 bind the promoter sequences of vascular, neuronal, and cancer‐related genes, while exhibiting subtle differences in cluster preference. Cerebrovascular gene promoters favor MZF1(ZF5–13), whereas neuronal and cancer‐related gene promoters display more variable involvement of the two ZF clusters. These results indicate that MZF1 uses its ZF clusters in a flexible and modular manner, providing a biochemical framework for understanding the differential behavior observed, which could be applied in future studies of MZF1‐mediated transcriptional regulation in biological systems.