These authors contributed equally to this work.
Cleavage of GSK-3β by calpain counteracts the inhibitory effect of Ser9 phosphorylation on GSK-3β activity induced by H2O2
Article first published online: 30 MAY 2013
© 2013 International Society for Neurochemistry
Journal of Neurochemistry
Volume 126, Issue 2, pages 234–242, July 2013
How to Cite
J. Neurochem. (2013)126, 234–242.
- Issue published online: 2 JUL 2013
- Article first published online: 30 MAY 2013
- Accepted manuscript online: 4 MAY 2013 11:40AM EST
- Manuscript Accepted: 30 APR 2013
- Manuscript Revised: 3 APR 2013
- Manuscript Received: 22 JAN 2013
- National Natural Science Foundation of China. Grant Numbers: 81271405, 31071226
- HEK293/Tau cells;
- hydrogen peroxide (H2O2)
Glycogen synthase kinase-3 beta (GSK-3β) dysfunction may play an essential role in the pathogenesis of psychiatric, metabolic, neurodegenerative diseases, in which oxidative stress exists concurrently. Some studies have shown that GSK-3β activity is up-regulated under oxidative stress. This study evaluated how oxidative stress regulates GSK-3β activity in human embryonic kidney 293 (HEK293)/Tau cells treated with hydrogen peroxide (H2O2). Here, we show that H2O2 induced an obvious increase of GSK-3β activity. Surprisingly, H2O2 dramatically increased phosphorylation of GSK-3β at Ser9, an inactive form of GSK-3β,while there were no changes of phosphorylation of GSK-3β at Tyr216. Moreover, H2O2 led to a transient [Ca2+]i elevation, and simultaneously increased the truncation of GSK-3β into two fragments of 40 kDa and 30 kDa, whereas inhibition of calpain decreased the truncation and recovered the activity of GSK-3β. Furthermore, tau was hyperphosphorylated at Ser396, Ser404, and Thr231, three most common GSK-3β targeted sites after 100 μM H2O2 administration in HEK293/Tau cells, whereas inhibition of calpain blocked the tau phosphorylation. In addition, we found that there were no obvious changes of Cyclin-dependent kinase 5 (CDK5) expression (responsible for tau phosphorylation) and of p35 cleavage, the regulatory subunit of CDK5 in H2O2-treated HEK293/Tau cells. In conclusion, Ca2+-dependent calpain activation leads to GSK-3β truncation, which counteracts the inhibitory effect of Ser9 phosphorylation, up-regulates GSK-3β activity, and phosphorylates tau in H2O2-treated HEK293/Tau cells.