YY1 Transcription Factor (YY1), a 414-amino-acid zinc-finger protein encoded by the YY1 gene, is a multifunctional transcription regulator widely expressed in eukaryotic cells. It exerts dual roles in gene expression, acting as either an activator or repressor depending on the cellular context, binding partners, and target gene promoters. YY1 participates in diverse biological processes, including embryonic development, cell proliferation, differentiation, apoptosis, and tumorigenesis. Its zinc-finger domain mediates specific DNA binding, while its N-terminal and C-terminal regions interact with various cofactors to modulate transcriptional activity. Dysregulation of YY1 is closely linked to multiple cancers, cardiovascular diseases, and neurological disorders due to its impact Reshaping gene expression profiles. YY1 interacts with PPARgC1a to co-regulate mitochondrial biogenesis and energy metabolism-related gene transcription.Thus a functional ELISA assay was conducted to detect the interaction of recombinant human YY1 and recombinant mouse PPARgC1a. Briefly, YY1 was diluted serially in PBS with 0.01% BSA (pH 7.4). Duplicate samples of 100 μl were then transferred to PPARgC1a-coated microtiter wells and incubated for 1h at 37℃. Wells were washed with PBST and incubated for 1h with anti-YY1 pAb, then aspirated and washed 3 times. After incubation with HRP labelled secondary antibody for 1h at 37℃, wells were aspirated and washed 5 times. With the addition of substrate solution, wells were incubated 15-25 minutes at 37℃. Finally, add 50 μL stop solution to the wells and read at 450/630nm immediately. The binding activity of recombinant human YY1 and recombinant mouse PPARgC1a was shown in Figure 1, the EC50?for this effect is 0.173μg/mL..