Secretion of Legumain Increases in Conditioned Medium from DJ-1-Knockout Cells and in Serum from DJ-1-Knockout Mice
Izumi Kato-Ose3
Tatsuji Sakamoto1 , 2
Yoshihisa Nakano1
Authors Info & Affiliations
Abstract
Background:
Asparaginyl endopeptidase, also known as legumain (EC 3.4.22.34) shows strong activity in the mouse kidney. Legumain is also highly expressed in tumors. DJ-1/PARK7 is a Parkinson’s disease- and cancer-associated protein. DJ-1 is a coactivator of various transcription factors. Recently, we reported that transcription of the legumain gene is regulated by p53 through DJ-1.
Methods:
We measured the secretion levels of legumain in a conditioned medium of DJ-1 knockout cells and in serum from DJ-1 knockout mice using Western blotting and ELISA. We performed immunocytochemical staining of legumain to examine the localization of legumain in DJ-1-knockout cells.
Results:
We found that the secretion levels of legumain were increased in the conditioned medium of DJ-1-knockout cells and in serum from DJ-1-knockout mice. Dot structures of legumain were also increased in DJ-1-knockout cells.
Conclusion:
The results suggest that legumain secretion from DJ-1-knockout cells and in mice increases through its increased expression and accumulation in membrane-associated vesicles.
