Insulin regulates MAP kinase phosphatase-1 induction in Hirc B cells via activation of both extracellular signal-regulated kinase (ERK) and c-Jun-N-terminal kinase (JNK).
Previously, we have reported that insulin induces the expression of the dual-specificity tyrosine phosphatase Mitogen-activated protein (MAP) kinase phosphatase-1 (MKP-1) and that this may represent a negative feedback mechanism to regulate insulin-stimulated MAP kinase activity. In this work, the mechanism of regulation of MKP-1 expression by insulin was examined, particularly the role of the MAP kinase superfamily. Inhibition of the ERK pathway attenuated insulin-stimulated MKP-1 mRNA expression. Expression of dominant negative molecules of the JNK pathway also abolished insulin-stimulated MKP-1 expression. However, inhibition of p38MAPK activity by SB202190 had no effect on insulin-stimulated MKP-1 induction. Simultaneous inhibition of the ERK and JNK pathways abolished the ability of insulin to stimulate MKP-1 expression, however, this combined inhibition was neither additive nor synergistic, suggesting these pathways converge to act on a common final effector. In conclusion, induction of MKP-1 mRNA expression in Hirc B cells by insulin requires activation of both the ERK and JNK pathways, but not p38MAPK.
Byon
J C
JC
Department of Physiology, Tulane University School of Medicine, New Orleans, LA, USA.
Dadke
S S
SS
Rulli
S
S
Kusari
A B
AB
Kusari
J
J
D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D018797:Cell Cycle Proteins; D002478:Cells, Cultured; D054638:Dual Specificity Phosphatase 1; D004789:Enzyme Activation / Q000187:drug effects; D004790:Enzyme Induction / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005347:Fibroblasts / Q000201:enzymology / Q000473:pathology / Q000502:physiology; D006801:Humans; D017874:Immediate-Early Proteins; D007328:Insulin / Q000378:metabolism*; D048031:JNK Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D020929:Mitogen-Activated Protein Kinase Kinases; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D017239:Paclitaxel / Q000494:pharmacology*; D010749:Phosphoprotein Phosphatases; D054645:Protein Phosphatase 1; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D017027:Protein Tyrosine Phosphatases; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D015398:Signal Transduction; D014162:Transfection; D048051:p38 Mitogen-Activated Protein Kinases
D000972:Antineoplastic Agents, Phytogenic; D018797:Cell Cycle Proteins; D004791:Enzyme Inhibitors; D017874:Immediate-Early Proteins; D007328:Insulin; D012333:RNA, Messenger; D017346:Protein Serine-Threonine Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D020929:Mitogen-Activated Protein Kinase Kinases; D010749:Phosphoprotein Phosphatases; D054645:Protein Phosphatase 1; C517019:DUSP1 protein, human; D054638:Dual Specificity Phosphatase 1; C517021:Dusp1 protein, rat; D017027:Protein Tyrosine Phosphatases; D017239:Paclitaxel