Nitric oxide (NO) is known to induce Zn²⁺ release from the zinc‐storing protein metallothio‐nein and to induce Zn²⁺ release within the nuclei and cytoplasm of cells. This suggests that zinc finger proteins may be primary targets of NO‐induced stress. In this study, the specific interaction of the heterodimeric complex of two zinc finger transcription factors, 1α,25‐dihydroxyvitamin D₃ (1α,25(OH)₂D₃) receptor (VDR) and retinoid × receptor (RXR) with 1α,25(OH)₂D₃ response elements (VDREs), was used as a model system. NO was applied to this system via the NO donors SNOC and MAMA/NO and caused a dose‐dependent inhibition of VDR‐RXR‐VDRE complex formation (IC₅₀ values 0.5–0.8 mM). Ligand‐bound or preformed complexes displayed less sensitivity to NO‐induced stress. These in vitro effects of NO were found to be reversible. Functional assays in transiently trans‐fected cells indicated that NO can also act in vivo as a repressor of 1α,25(OH)₂D₃ signaling (IC₅₀ value of the slow NO donor DETA/NO, 0.5 mM). These findings suggest that NO has a modulatory role on transcription factors depending on their sensitivity to NO‐induced stress, thus providing a mechanism for a gene regulatory function of NO.—Krõncke, K. D., Carlberg, C. Inactivation of zinc finger transcription factors provides a mechanism for a gene regulatory role of nitric oxide. FASEB J. 13, 166–173 (2000)