Induction of cyclin-dependent kinase 5 and its activator p35 through the extracellular-signal-regulated kinase and protein kinase A pathways during retinoic-acid mediated neuronal differentiation in human neuroblastoma SK-N-BE(2)C cells.
Cyclin-dependent kinase 5 (Cdk5), a neuronal Cdc2-like kinase, exhibits a variety of functions in neuronal differentiation and neurocytoskeleton dynamics, as well as neuronal degeneration. However, its role and induction mechanisms in retinoic acid (RA)-induced neuronal differentiation have not been well understood. In this study we newly found that RA treatment of SK-N-BE(2)C, human neuroblastoma cells, increased the expression of Cdk5 and its neuron specific activator p35 through the extracellular-signal-regulated kinase1/2 (ERK1/2) and cAMP-dependent protein kinase A (PKA) pathway. Inhibition of Cdk5 activity either by an inhibitor, roscovitine, or by transfection with a dominant negative form of Cdk5 caused a dramatic decrease in RA-induced differentiation, suggesting the requirement of Cdk5 kinase activity for the RA-induced neurite outgrowth. Furthermore, Cdk5 and p35 expression was decreased by ERK1/2 inhibition with PD98059 and increased by overexpression of a constitutive active mitogen-activated protein kinase kinase 1 (MEK1) mutant, suggesting the critical role of ERK1/2 in the induction of Cdk5 and p35. In addition, a transcription factor early growth response 1 (Egr-1) was induced by RA through the ERK1/2 pathway, suggesting its possible involvement in the p35 induction. RA treatment also induced c-fos mediated AP-1 binding, and cAMP-responsive element binding protein (CREB) mediated CRE binding via ERK1/2 and PKA pathway, respectively, in the Cdk5 promoter region, resulting in the induction of Cdk5. Our results suggest that ERK1/2 and PKA-induced regulation of Cdk5 activity possibly through Egr-1, c-fos, and CREB plays a critical role in the RA-induced neuronal differentiation.
Department of Life Science, Division of Molecular and Life Science, Pohang University of Science and Technology, Pohang 790-784, Korea.
Jong-Hee
JH
Lee
Kyong-Tai
KT
Kim
D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D045744:Cell Line, Tumor; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D051360:Cyclin-Dependent Kinase 5; D018844:Cyclin-Dependent Kinases / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D051766:Early Growth Response Protein 1; D004790:Enzyme Induction / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D006801:Humans; D017874:Immediate-Early Proteins / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D016501:Neurites / Q000502:physiology; D009447:Neuroblastoma / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism*; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D014157:Transcription Factors / Q000378:metabolism; D014162:Transfection; D014212:Tretinoin / Q000494:pharmacology*
D017362:Cyclic AMP Response Element-Binding Protein; D004268:DNA-Binding Proteins; C497325:EGR1 protein, human; D051766:Early Growth Response Protein 1; D017874:Immediate-Early Proteins; D009419:Nerve Tissue Proteins; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D014157:Transcription Factors; C089495:neuronal Cdk5 activator (p25-p35); D014212:Tretinoin; D051360:Cyclin-Dependent Kinase 5; D017868:Cyclic AMP-Dependent Protein Kinases; C495905:CDK5 protein, human; D018844:Cyclin-Dependent Kinases; D048049:Extracellular Signal-Regulated MAP Kinases