Asparagine Synthetase Is Partially Localized to the Plasma Membrane and Upregulated by L-asparaginase in U937 Cells
- Author:
HE YINGYI
1
;
LI BENSHANG
;
LUO CHANGYING
;
SHEN SHUHONG
;
CHEN JING
;
XUE HUILIANG
;
TANG JINGYAN
;
GU LONGJUN
Author Information
1. Department of Hematology/Oncology, Shanghai Children's Medical Center, Shanghai Jiaotong University School of Medicine,Shanghai, 200127, China
- Keywords:
asparagine synthetase;
L-asparaginase;
acute myeloid leukemia;
drug resistance;
plasma membrane
- From:
Journal of Huazhong University of Science and Technology (Medical Sciences)
2011;31(2):159-163
- CountryChina
- Language:Chinese
-
Abstract:
This study investigated the intracellular localization of asparagine synthetase (ASNS) in the relation with chemoresistance in leukemia.pIRES-GFP-ASNS-Flag/Neo expression vector was transiently tansfected into SK-N-MC cells and 297T cells respectively.Immunofluorescence and Western blot analysis were performed for cellular localization of ASNS respectively.U937 cells were treated with L-asparaginase for 48 h and examined for endogenous ASNS expression on plasma membrane by immunofluorescence staining.Immunofluorescence staining showed that the transiently expressed ASNS was partly localized on transfected-SK-N-MC cell surface.Moreover,Western blotting exhibited that ASNS expressed both in cytosol and on plasma membrane of transfected-293T cells.Immunofluo-rescence staining with anti-ASNS-specific monoclonal antibody revealed that endogenous ASNS was localized on the plasma membrane of U937 cells,except for its distribution in the cytosol.In addition,ASNS exhibited a higher expression on plasma membrane after treatment with L-asparaginase as compared with the untreated cells.It was concluded that the subcellular translocation of ASNS may play an important role in L-asparaginase resistance in leukemia cells.
