IndraLab
Statements
rlimsp
"Akt and apoptosis signal-regulating kinase 1 (ASK1) were physically associated, and E2 induced the phosphorylation of ASK1 at serine-83, which is a consensus Akt phosphorylation site. We confirmed a previous report showing that paclitaxel induces cell damage via the ASK1-c-Jun N-terminal protein kinase (JNK) cascade. E2 inhibited the paclitaxel-induced JNK activation, and the E2-induced inhibition of the paclitaxel-induced JNK activation was attenuated in cells treated with either ICI182,780 or LY294002 or transfected with ASK1S83A, in which a consensus Akt phosphorylation site at serine-83 was converted to alanine."
rlimsp
"Exposure of INS‐1 β‐cells transfected with human ASK1 to thapsigargin was found to increase phosphorylation of Thr845 and reduce phosphorylation of Ser83 in ASK1, changes that increase its enzyme activity, resulting in phosphorylation and activation of p38 MAPK and JNK, through MAPK/extracellular signal‐regulated kinase (ERK) kinase (Mek) 3/6 and Mek 4/7, respectively. Activation of PKB with GIP treatment prevented these changes in ASK1 phosphorylation and downstream targets. Suppressing ASK1 activation with GIP treatment inhibited apoptosis induced by all apoptosis‐inducing agents tested. As a result of the complexity of the system, the mechanism of GIP action is currently only open to speculation. In non‐stressed cells, ASK1 forms a high molecular weight complex that has been termed the ‘ASK1 signalosome’, and, in non‐stressed cells when ASK1 activity is inhibited, the anti‐oxidative protein, thioredoxin (Trx), is a component of the signalosome. If the oxidative state of the cell is greatly increased, the oxidized form of Trx dissociates from ASK1 and tumor necrosis factor (TNF) receptor‐associated factor 2 (TRAF2) and TRAF6 binding activates ASK1 signaling. Although GIP‐stimulated phosphorylation of Ser83 by Akt was clearly involved in inhibiting ASK1 activity, it is also possible that the binding of thioredoxin and/or TRAF2/6 to ASK1 were impacted on."