Secretion of Legumain Increases in Conditioned Medium from DJ-1-Knockout Cells and in Serum from DJ-1-Knockout Mice

Takuya Yamane; Izumi Kato-Ose; Tatsuji Sakamoto; Yoshihisa Nakano

doi:10.2174/1874091X01812010029

Secretion of Legumain Increases in Conditioned Medium from DJ-1-Knockout Cells and in Serum from DJ-1-Knockout Mice

Open Biochem J. 2018 Feb 28:12:29-35. doi: 10.2174/1874091X01812010029. eCollection 2018.

Authors

Takuya Yamane^{1

2}, Izumi Kato-Ose³, Tatsuji Sakamoto^{1

2}, Yoshihisa Nakano¹

Affiliations

¹ Center for Research and Development Bioresources, Research Organization for University-Community Collaborations, Osaka Prefecture University, Sakai, Osaka 599-8570, Japan.
² Department of Applied Life Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan.
³ Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-ku, Sapporo 060-0812, Japan.

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.

Keywords: DJ-1; Gene; Knockout mice; Legumain; Secretion; Western blotting; p53.