Yamane Takuya, Kato-Ose Izumi, Sakamoto Tatsuji, Nakano Yoshihisa
Center for Research and Development Bioresources, Research Organization for University-Community Collaborations, Osaka Prefecture University, Sakai, Osaka 599-8570, Japan.
Department of Applied Life Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan.
Open Biochem J. 2018 Feb 28;12:29-35. doi: 10.2174/1874091X01812010029. eCollection 2018.
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.
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.
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.
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.
天冬酰胺内肽酶，也称为豆荚天冬酰胺酶（EC 3.4.22.34），在小鼠肾脏中显示出很强的活性。豆荚天冬酰胺酶在肿瘤中也高度表达。DJ-1/PARK7是一种与帕金森病和癌症相关的蛋白质。DJ-1是多种转录因子的共激活因子。最近，我们报道了豆荚天冬酰胺酶基因的转录受p53通过DJ-1调控。
我们使用蛋白质免疫印迹法和酶联免疫吸附测定法，测定DJ-1基因敲除细胞的条件培养基和DJ-1基因敲除小鼠血清中豆荚天冬酰胺酶的分泌水平。我们对豆荚天冬酰胺酶进行免疫细胞化学染色，以检查其在DJ-1基因敲除细胞中的定位。
我们发现，DJ-1基因敲除细胞的条件培养基和DJ-1基因敲除小鼠血清中豆荚天冬酰胺酶的分泌水平升高。DJ-1基因敲除细胞中豆荚天冬酰胺酶的点状结构也增加。
结果表明，DJ-1基因敲除细胞和小鼠中豆荚天冬酰胺酶的分泌增加，是由于其在膜相关囊泡中的表达和积累增加。
