Dynamin I is highly expressed in brain and plays a critical role in clathrin-mediated endocytosis and synaptic vesicle recycling. To elucidate the molecular mechanism by which expression of dynamin I is tissue-specifically regulated, we previously cloned and characterized the promoter of the mouse dynamin I gene and suggested that there is a negative regulatory element in this promoter region. In the present study, we showed that YY1 binds to this negative regulatory element located at -111 to -107 by using the EMSA and supershift analyses. Cotransfection experiment using an YY1 expression vector revealed that YY1 exerts a repressive role on the dynamin I gene promoter activity. These results demonstrate that transcription factor YY1 negatively regulates dynamin I expression via binding to the negative regulatory element.