Negative regulation of MEKK1-induced signaling by glutathione S-transferase Mu.
Mitogen-activated protein kinase/extracellular signal-regulated kinase kinase kinase 1 (MEKK1) is an important component in the stress-activated protein kinase pathway. Glutathione S-transferase Mu 1-1 (GST M1-1) has now been shown to inhibit the stimulation of MEKK1 activity induced by cellular stresses such as UV and hydrogen peroxide. GST M1-1 inhibited MEKK1 activation in a manner independent of its glutathione-conjugating catalytic activity. In vitro binding and kinase assays revealed that GST M1-1 directly bound MEKK1 and inhibited its kinase activity. Co-immunoprecipitation analysis showed a physical association between endogenous GST M1-1 and endogenous MEKK1 in L929 cells. Overexpressed GST M1-1 interfered with the binding of MEKK1 to SEK1 in transfected HEK293 cells. Furthermore, GST M1-1 suppressed MEKK1-mediated apoptosis. Taken together, our results suggest that GST M1-1 functions as a negative regulator of MEKK1.
National Creative Research Initiative Center for Cell Death, School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, South Korea.
Kanghyun
K
Ryoo
Sung-Ho
SH
Huh
Yong Hee
YH
Lee
Kyoung Wan
KW
Yoon
Ssang-Goo
SG
Cho
Eui-Ju
EJ
Choi
D000818:Animals; D002460:Cell Line; D003001:Cloning, Molecular; D005982:Glutathione Transferase / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D007739:L Cells; D048728:MAP Kinase Kinase Kinase 1 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051379:Mice; D011994:Recombinant Proteins / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology*
D011994:Recombinant Proteins; D005982:Glutathione Transferase; D048728:MAP Kinase Kinase Kinase 1