TY - JOUR
T1 - Variable regulation of glutamate cysteine ligase subunit proteins affects glutathione biosynthesis in response to oxidative stress
AU - Krzywanski, David M.
AU - Dickinson, Dale A.
AU - Iles, Karen E.
AU - Wigley, Amanda F.
AU - Franklin, Christopher C.
AU - Liu, Rui Ming
AU - Kavanagh, Terrance J.
AU - Forman, Henry Jay
N1 - Funding Information:
This work was supported by Grants ES05511 to H.J.F., CA75316, and CA90473 to C.C.F. from the National Institutes of Health.
PY - 2004/3/1
Y1 - 2004/3/1
N2 - Glutamate cysteine ligase (GCL), composed of a catalytic (GCLC) and modulatory (GCLM) subunit, catalyzes the first step of glutathione (GSH) biosynthesis. Using 4-hydroxy-2-nonenal (4HNE), 2,3-dimethoxy-1, 4-naphthoquinone (DMNQ), and tertiary-butylhydroquinone (tBHQ) as models of oxidative stress which are known to work through different mechanisms, we measured changes in cellular GSH, GCL mRNA, and GCL protein. 4HNE and tBHQ treatments increased cellular GSH levels, while DMNQ exposure depleted GSH. Furthermore, changes in the two GCL mRNAs largely paralleled changes in the GCL proteins; however, the magnitudes differed, suggesting some form of translational control. The molar ratio of GCLC:GCLM ranged from 3:1 to 17:1 in control human bronchial epithelial (HBE1) cells and all treatments further increased this ratio. Data from several mouse tissues show molar ratios of GCLC:GCLM that range from 1:1 to 10:1 in support of these findings. These data demonstrate that alterations in cellular GSH are clearly correlated with GCLC to a greater extent than GCLM. Surprisingly, both control HBE1 cells and some mouse tissues have more GCLC than GCLM and GCLM increases to a much lesser extent than GCLC, suggesting that the regulatory role of GCLM is minimal under physiologically relevant conditions of oxidative stress.
AB - Glutamate cysteine ligase (GCL), composed of a catalytic (GCLC) and modulatory (GCLM) subunit, catalyzes the first step of glutathione (GSH) biosynthesis. Using 4-hydroxy-2-nonenal (4HNE), 2,3-dimethoxy-1, 4-naphthoquinone (DMNQ), and tertiary-butylhydroquinone (tBHQ) as models of oxidative stress which are known to work through different mechanisms, we measured changes in cellular GSH, GCL mRNA, and GCL protein. 4HNE and tBHQ treatments increased cellular GSH levels, while DMNQ exposure depleted GSH. Furthermore, changes in the two GCL mRNAs largely paralleled changes in the GCL proteins; however, the magnitudes differed, suggesting some form of translational control. The molar ratio of GCLC:GCLM ranged from 3:1 to 17:1 in control human bronchial epithelial (HBE1) cells and all treatments further increased this ratio. Data from several mouse tissues show molar ratios of GCLC:GCLM that range from 1:1 to 10:1 in support of these findings. These data demonstrate that alterations in cellular GSH are clearly correlated with GCLC to a greater extent than GCLM. Surprisingly, both control HBE1 cells and some mouse tissues have more GCLC than GCLM and GCLM increases to a much lesser extent than GCLC, suggesting that the regulatory role of GCLM is minimal under physiologically relevant conditions of oxidative stress.
KW - 4HNE
KW - DMNQ
KW - GCL
KW - GCS
KW - Glutathione
KW - Molar ratio
KW - Oxidative stress
KW - TBHQ
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U2 - 10.1016/j.abb.2003.11.004
DO - 10.1016/j.abb.2003.11.004
M3 - Article
C2 - 14871475
AN - SCOPUS:1042267392
SN - 0003-9861
VL - 423
SP - 116
EP - 125
JO - Archives of Biochemistry and Biophysics
JF - Archives of Biochemistry and Biophysics
IS - 1
ER -