Objective Hepatocyte nuclear factor 4-alpha (HNF4A) is a critical transcription factor in the liver and pancreas. Dysfunctions of HNF4A lead to maturity onset diabetes of the young (MODY1). Notably, MODY1 patients with HNF4A pathogenic mutations exhibit decreased responses to arginine and reduced plasma triglyceride levels, but the mechanisms remain unclear. This study aims to investigate the potential target genes transcriptionally regulated by HNF4A and explore its role in these metabolic pathways.Methods A stable 293T cell line expressing the HNF1A reporter was overexpressed with HNF4A. RNA sequencing (RNA-seq) was performed to analyze transcriptional differences. Transcription factor binding site prediction was then conducted to identify HNF4A binding motifs in the promoter regions of relevant target genes.Results RNA-seq results revealed a significant upregulation of transmembrane 4 L six family member 5 (TM4SF5) mRNA in HNF4A-overexpressing cells. Transcription factor binding predictions suggested the presence of five potential HNF4A binding motifs in the TM4SF5 promoter. Finally, we confirmed that the DR1 site in the -57 to -48 region of the TM4SF5 promoter is the key binding motif for HNF4A.Conclusion This study is the first to identify TM4SF5 as a target gene of HNF4A and to determine the key binding motif involved in its regulation. Given the role of TM4SF5 as an arginine sensor in mTOR signaling activation and triglyceride secretion, which closely aligns with phenotypes observed in MODY1 patients, our findings provide novel insights into how HNF4A regulates triglyceride secretion in the liver and arginine-stimulated insulin secretion in the pancreas.