Upstream stimulatory factor 1 (USF1) is a member of the basic helix-loop-helix family of transcription factors and is involved in the regulation of various genes related to cellular metabolism, cell growth, and stress responses. The USF1 luciferase reporter vector is designed to study the transcriptional activity of USF1. The vector contains a USF1 DNA consensus binding site and TA minimal promoter upstream of a firefly luciferase reporter gene, which can specifically report USF1 activity while maintaining a low basal level of transcription.