Effect of glucose concentration on activation of the ASK1-SEK1-JNK1 signal transduction pathway.

Recently, acute total glucose deprivation has been shown to cause activation of ASK1-MEK-MAPK signal transduction and dissociation of glutaredoxin (GRX) from apoptosis signal-regulating kinase 1 (ASK1). In this study, we investigated whether clinically relevant concentrations (0.01-0.1 mM) of glucose promote ASK1 activation. We observed that a prominent activation of JNK1 occurred at a glucose concentration less than or equal to 0.01 mM. Similar to JNK1 activation, we also observed that low glucose-induced ASK1 activation, dissociation of GRX and thioredoxin (TRX) from ASK1, dimerization of ASK1, and association of Daxx and TRAF2 with ASK1 significantly occurred at a glucose concentration less than or equal to 0.01 mM.