SUMO negatively regulates BACE expression.

OBJECTIVE: The effect of SUMO on the promoter activity and mRNA expression of BACE gene was investigated to find the connection between sumoylation and APP processing. METHODS: The BACE promoter activity was measured by reporter gene analysis and BACE mRNA level was investigated using real-time RT-PCR method. RESULTS: BACE gene promoter activity was inhibited by the over-expression of SUMO proteins and was blocked by disrupting the SP1 site. Endogenous BACE mRNA level was also negatively regulated by the induction of SUMO proteins. Using a specific inhitor of SP1, BACE promoter activity was coordinately inhibited. CONCLUSIONS: SUMO negatively regulates the BACE expression and SP1 is involved in the process.