ERK5 Activity Is Required for Nerve Growth Factor-induced Neurite Outgrowth and Stabilization of Tyrosine Hydroxylase in PC12 Cells

Extracellular signal-regulated kinases (ERKs) play important physiological roles in proliferation, differentiation, and gene expression. ERK5 is approximately twice the size of ERK1/2, and its amino-terminal half contains the kinase domain that shares homology with ERK1/2 and TEY activation motif, whereas the carboxyl-terminal half is unique. In this study, we examined a physiological role of ERK5 in rat pheochromocytoma cells (PC12), comparing it with ERK1/2. Nerve growth factor (NGF) induced phosphorylation of both ERK5 and ERK1/2, whereas the cAMP analog dibutyryl cAMP (Bt2cAMP) caused only ERK1/2 phosphorylation. U0126, at 30 μm, that blocks ERK1/2 signaling selectively attenuated neurite outgrowth induced by NGF and Bt2cAMP, but BIX02188 and BIX02189, at 30 μm, that block ERK5 signaling and an ERK5 dominant-negative mutant suppressed only NGF-induced neurite outgrowth. Next, we examined the expression of tyrosine hydroxylase, a rate-limiting enzyme of catecholamine biosynthesis. Both NGF and Bt2cAMP increased tyrosine hydroxylase gene promoter activity in an ERK1/2-dependent manner but was ERK5-independent. However, when both ERK5 and ERK1/2 signalings were inhibited, tyrosine hydroxylase protein up-regulation by NGF and Bt2cAMP was abolished, because of the loss of stabilization of tyrosine hydroxylase protein by ERK5. Taking these results together, ERK5 is involved in neurite outgrowth and stabilization of tyrosine hydroxylase in PC12 cells, and ERK5, along with ERK1/2, plays essential roles in the neural differentiation process. Extracellular signal-regulated kinases (ERKs) play important physiological roles in proliferation, differentiation, and gene expression. ERK5 is approximately twice the size of ERK1/2, and its amino-terminal half contains the kinase domain that shares homology with ERK1/2 and TEY activation motif, whereas the carboxyl-terminal half is unique. In this study, we examined a physiological role of ERK5 in rat pheochromocytoma cells (PC12), comparing it with ERK1/2. Nerve growth factor (NGF) induced phosphorylation of both ERK5 and ERK1/2, whereas the cAMP analog dibutyryl cAMP (Bt2cAMP) caused only ERK1/2 phosphorylation. U0126, at 30 μm, that blocks ERK1/2 signaling selectively attenuated neurite outgrowth induced by NGF and Bt2cAMP, but BIX02188 and BIX02189, at 30 μm, that block ERK5 signaling and an ERK5 dominant-negative mutant suppressed only NGF-induced neurite outgrowth. Next, we examined the expression of tyrosine hydroxylase, a rate-limiting enzyme of catecholamine biosynthesis. Both NGF and Bt2cAMP increased tyrosine hydroxylase gene promoter activity in an ERK1/2-dependent manner but was ERK5-independent. However, when both ERK5 and ERK1/2 signalings were inhibited, tyrosine hydroxylase protein up-regulation by NGF and Bt2cAMP was abolished, because of the loss of stabilization of tyrosine hydroxylase protein by ERK5. Taking these results together, ERK5 is involved in neurite outgrowth and stabilization of tyrosine hydroxylase in PC12 cells, and ERK5, along with ERK1/2, plays essential roles in the neural differentiation process. ERKs 2The abbreviations used are: ERKextracellular signal-regulated kinasePC12pheochromocytoma cellsNGFnerve growth factorBt2cAMPdibutyryl cAMPMAPKmitogen-activated protein kinaseEGFepidermal growth factorBDNFbrain-derived neurotrophic factorGPCRG-protein-coupled receptorHRPhorseradish peroxidaseDMEMDulbecco's modified Eagle's mediumCREBcAMP-response element-binding proteinGSK3βglycogen synthase kinase-3βm.o.i.multiplicity of infectionsiRNAsmall interfering RNAGFPgreen fluorescent proteinEGFPenhanced GFP. or MAPKs are involved in proliferation, differentiation, migration, and gene expression. ERK1/2 is activated by variety of stimuli, and the signaling pathway leading to ERK1/2 activation has been well characterized (1.Goldsmith Z.G. Dhanasekaran D.N. Oncogene. 2007; 26: 3122-3142Crossref PubMed Scopus (324) Google Scholar, 2.Nishida E. Gotoh Y. Trends Biochem. Sci. 1993; 18: 128-131Abstract Full Text PDF PubMed Scopus (964) Google Scholar, 3.Robinson M.J. Cobb M.H. Curr. Opin. Cell Biol. 1997; 9: 180-186Crossref PubMed Scopus (2286) Google Scholar). ERK5 is approximately double the molecular size of ERK1/2. The kinase domain is encoded by its amino-terminal half and shares ∼50% homology with ERK1/2, whereas its unique carboxyl terminus encodes two proline-rich regions, a nuclear export domain and a nuclear localization domain (4.Wang X. Tournier C. Cell. Signal. 2006; 18: 753-760Crossref PubMed Scopus (222) Google Scholar, 5.Nishimoto S. Nishida E. EMBO Rep. 2006; 7: 782-786Crossref PubMed Scopus (347) Google Scholar). Recently, it was reported that the autophosphorylated carboxyl terminus of ERK5 plays a critical role in activating transcription (6.Morimoto H. Kondoh K. Nishimoto S. Terasawa K. Nishida E. J. Biol. Chem. 2007; 282: 35449-35456Abstract Full Text Full Text PDF PubMed Scopus (80) Google Scholar). The threonine and tyrosine residues on ERK5 are phosphorylated by MEK5 but not MEK1/2. In contrast, ERK1/2 is not phosphorylated by MEK5 but is phosphorylated by MEK1/2 (7.English J.M. Vanderbilt C.A. Xu S. Marcus S. Cobb M.H. J. Biol. Chem. 1995; 270: 28897-28902Abstract Full Text Full Text PDF PubMed Scopus (187) Google Scholar, 8.Zhou G. Bao Z.Q. Dixon J.E. J. Biol. Chem. 1995; 270: 12665-12669Abstract Full Text Full Text PDF PubMed Scopus (540) Google Scholar). extracellular signal-regulated kinase pheochromocytoma cells nerve growth factor dibutyryl cAMP mitogen-activated protein kinase epidermal growth factor brain-derived neurotrophic factor G-protein-coupled receptor horseradish peroxidase Dulbecco's modified Eagle's medium cAMP-response element-binding protein glycogen synthase kinase-3β multiplicity of infection small interfering RNA green fluorescent protein enhanced GFP. Several physiological roles of ERK5 have been reported (4.Wang X. Tournier C. Cell. Signal. 2006; 18: 753-760Crossref PubMed Scopus (222) Google Scholar, 5.Nishimoto S. Nishida E. EMBO Rep. 2006; 7: 782-786Crossref PubMed Scopus (347) Google Scholar, 9.Cavanaugh J.E. Eur. J. Biochem. 2004; 271: 2056-2059Crossref PubMed Scopus (72) Google Scholar). For example, ERK5 regulates S-phase entry by epidermal growth factor (EGF) in HeLa cells (10.Kato Y. Tapping R.I. Huang S. Watson M.H. Ulevitch R.J. Lee J.D. Nature. 1998; 395: 713-716Crossref PubMed Scopus (360) Google Scholar). In dorsal root ganglia, ERK5 is activated by nerve growth factor (NGF) during retrograde transport of TrkA, and this action prevents apoptosis (11.Watson F.L. Heerssen H.M. Bhattacharyya A. Klesse L. Lin M.Z. Segal R.A. Nat. Neurosci. 2001; 4: 981-988Crossref PubMed Scopus (384) Google Scholar). In developing cortical neurons, ERK5 plays a critical role in survival promoted by brain-derived neurotrophic factor (BDNF) (12.Liu L. Cavanaugh J.E. Wang Y. Sakagami H. Mao Z. Xia Z. Proc. Natl. Acad. Sci. U.S.A. 2003; 100: 8532-8537Crossref PubMed Scopus (144) Google Scholar). Neuronal differentiation is by ERK5 in S. Nishida E. EMBO Rep. PubMed Scopus Google Scholar). ERK5 is of cortical L. G. Wang Y. Sakagami H. Xu Xia Z. Proc. Natl. Acad. Sci. U.S.A. 2006; PubMed Scopus Google Scholar). In ERK5 gene is at because of the of ERK5 in Lee J.D. J. 2004; PubMed Scopus Google Scholar). roles ERK5 have been and (4.Wang X. Tournier C. Cell. Signal. 2006; 18: 753-760Crossref PubMed Scopus (222) Google Scholar). ERK5 plays essential physiological roles in to ERK1/2. In rat pheochromocytoma cells (PC12), and NGF ERK5 the small S. Nishida E. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). it has been that ERK5 in cortical Y. Xia Z. J. Biol. Chem. 2006; Full Text Full Text PDF PubMed Scopus Google Scholar). In the of with is involved in activation of ERK5 X. K. J. Cell. Biol. 2003; PubMed Scopus Google whereas in cells, protein kinase ERK5 activation and G. Cell. PubMed Scopus Google Scholar). G-protein-coupled receptor ERK5. For example, and ERK5 and of (1.Goldsmith Z.G. Dhanasekaran D.N. Oncogene. 2007; 26: 3122-3142Crossref PubMed Scopus (324) Google Scholar, S. M.J. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). The ERK5 activation by and is not by dominant-negative of and the that S. M.J. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). In contrast, and both of cAMP ERK5 phosphorylation induced by protein kinase S. Cobb M.H. Cell. Biol. 2006; 26: PubMed Scopus Google Scholar). In we reported that of activated by ERK5 activation by and NGF in PC12 cells Y. Y. S. A. H. Cell. Signal. PubMed Scopus Google Scholar). the of ERK5 is and the PC12 cells are a in of In to Proc. Natl. Acad. Sci. U.S.A. PubMed Scopus Google Scholar). have that NGF and cAMP ERK1/2 phosphorylation or in PC12 cells, and ERK1/2 activation is essential neurite outgrowth by NGF or cAMP Y. K. J. Cell Sci. 2004; PubMed Scopus Google Scholar). the role of ERK5 in neural differentiation is S. Nishida E. EMBO Rep. PubMed Scopus Google Scholar, L. G. Wang Y. Sakagami H. Xu Xia Z. Proc. Natl. Acad. Sci. U.S.A. 2006; PubMed Scopus Google the molecular in differentiation in this study, we to the physiological role of ERK5 in the neural differentiation on neurite outgrowth and gene expression tyrosine Bt2cAMP, and and were was and were U0126, ERK1/2, ERK5, and tyrosine hydroxylase and horseradish peroxidase were Cell ERK5 and were and were was hydroxylase was BIX02188 and were tyrosine hydroxylase was by activity of factor and were by Xia of J.E. J. S. C. Xia Z. J. Neurosci. 2001; PubMed Google Scholar). and were Nishida mutant was in this by the was by was J.M. Cell. Biol. PubMed Scopus Google Scholar). was Z. S. K. Cell. Biol. 2006; 26: PubMed Scopus Google Scholar). PC12 cells were the The cells were in Dulbecco's modified Eagle's medium with and in an at PC12 cells that dominant-negative MEK5 were in the of PC12 cells that J. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google the cells were with and in the of the and cells were by cells were in with and the was on were the by the The were with in at and with at The were and with or a in at with were a and by the the the to the enhanced The of the to tyrosine hydroxylase were by of was a that of EMBO J. 1997; PubMed Scopus Google Scholar). cells were in of were by and of protein were with of protein of J. L. The by with an at were with and protein was the with The of to the was by to The neurite PC12 cells was an of The cells were with and the were with The were with The of and of were with the and the of neurite by was neurite For the of and neurite in cells were selectively by the are of the of Y. Y. J. PubMed Scopus Google Scholar). The were PC12 cells the the cells were at and a The of of of and of or of of of and of ERK5 or of tyrosine hydroxylase of ERK5 or MEK5 and of and were in and at the of this was to the been with The cells were at and the were with growth medium and For gene the cells were with at and to were in the to the the was with of The was by of and activity was a an activity was in the to the PC12 cells were with dominant-negative and that block of and Y. J. 2007; PubMed Scopus Google Scholar). The infection was at at was to cells with at cells were with infection the medium was with and the cells were with were the and were NGF or cAMP ERK5 in PC12 cells, PC12 cells were with NGF or Bt2cAMP phosphorylation of ERK5 and ERK1/2 was by NGF induced the phosphorylation of ERK5 and ERK1/2 Y. K. J. Cell Sci. 2004; PubMed Scopus Google Scholar, H. Nature. 1998; PubMed Scopus Google Scholar). In contrast, Bt2cAMP induced ERK1/2 it not ERK5 phosphorylation. it has been reported that and U0126, block MEK5 well MEK1/2 S. Nishida E. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google it has been that these not block ERK5 signaling at E. E. S. A. S. J. PubMed Scopus Google Scholar, Z. E. S. G. H. G. H. J. 2007; PubMed Scopus Google Scholar, J. C. Dixon J. 2001; PubMed Scopus Google Scholar). the of these in PC12 cells were with or 30 30 and with NGF or Bt2cAMP ERK1/2 phosphorylation by both was by with U0126, ERK5 phosphorylation was not at suppressed ERK1/2 phosphorylation by NGF and Bt2cAMP but not ERK5 phosphorylation by NGF these we used a ERK1/2 signaling in this Recently, BIX02188 and were of the pathway R.J. C.A. S. R.J. Biochem. PubMed Scopus Google Scholar). PC12 cells were with or BIX02188 and 30 and the cells were with NGF Both ERK5 phosphorylation in a whereas phosphorylation of ERK1/2 were we used BIX02188 and ERK5 signaling in this Next, we to the of dominant-negative of ERK5 or cells were with the MEK5 mutant and ERK5 or dominant-negative ERK5 mutant caused phosphorylation of both and but the of was because its kinase activity and has been that ERK5 and at that is critical In kinase activated by ERK1/2 on that is activation Y. L. Xia Z. J. 2007; PubMed Scopus Google Scholar). the of on ERK5 transcription was PC12 cells were by NGF in the of and a NGF promoted and this was by mutant is a ERK1/2 signaling H. Cell. 1997; Full Text Full Text PDF PubMed Scopus Google we examined or dominant-negative MEK5 mutant with ERK1/2 phosphorylation induced by in PC12 ERK1/2 the phosphorylation was not by or expression phosphorylation by ERK1/2 was an of in ERK1/2 kinase and it has been that ERK5 not S. Nishida E. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar, J.E. J. S. C. Xia Z. J. Neurosci. 2001; PubMed Google Scholar). NGF promoted ERK1/2 and this was by but not by or results that or not ERK1/2 it has been that regulates ERK5 activity in PC12 cells and cells S. Nishida E. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google are that was not involved in ERK5 activation by growth or and (10.Kato Y. Tapping R.I. Huang S. Watson M.H. Ulevitch R.J. Lee J.D. Nature. 1998; 395: 713-716Crossref PubMed Scopus (360) Google Scholar, S. M.J. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). the small is ERK5 activation by in cortical Y. Xia Z. J. Biol. Chem. 2006; Full Text Full Text PDF PubMed Scopus Google Scholar). have results that activated by protein activated by cAMP ERK5 activity protein protein kinase protein J. J.D. Nature. PubMed Scopus Google Scholar). the of and in ERK5 activation is we to the of these small in ERK5 activation in PC12 PC12 cells were with dominant-negative mutant of at the cells were with NGF or the ERK1/2 phosphorylation by NGF and was by ERK5 phosphorylation by these growth was to that is not involved in ERK5 phosphorylation by NGF and in PC12 cells that activity was by infection at and PC12 cells were with NGF ERK5 phosphorylation was to in the of In activity was by infection of not a is to activation by NGF H. Nature. 1998; PubMed Scopus Google Scholar, S. K. Y. J. Cell Biol. 2007; PubMed Scopus Google Scholar). we to block activation by In the that expression is by ERK5 phosphorylation was not ERK5 phosphorylation by NGF or was examined in PC12 cells that However, ERK5 phosphorylation was not by NGF or In cells, activation by NGF was by with Taking these results together, ERK5 phosphorylation by NGF is and PC12 cells in to NGF or Bt2cAMP in an ERK1/2-dependent manner Y. K. J. Cell Sci. 2004; PubMed Scopus Google Scholar). we that attenuated the neurite outgrowth by both NGF and Bt2cAMP both BIX02188 and neurite by NGF in PC12 cells ERK5 is the NGF-induced neurite outgrowth. Next, PC12 cells were with and or and with NGF or Bt2cAMP cells were the NGF-induced neurite However, the neurite outgrowth induced by Bt2cAMP was not attenuated by the neurite outgrowth induced by NGF but not Bt2cAMP was in PC12 cells that and that ERK5 activity is the NGF-induced neurite outgrowth in PC12 ERK5 is neurite the cells were with and or ERK5. was used a caused neurite ERK5 not neurite outgrowth in PC12 cells ERK5 is but not neurite outgrowth induced by NGF is by of dominant-negative ERK5 and PC12 cells were with and or The cells were with NGF or Bt2cAMP a The were with and of cells were a of PC12 cells was the NGF and Bt2cAMP increased neurite and the of NGF was by PC12 cells or PC12 cells mutant were with NGF or Bt2cAMP a The were with and the were of PC12 cells was the NGF and Bt2cAMP increased neurite and the of NGF was by is not neurite outgrowth in PC12 PC12 cells were with and or the cells were The were with and of cells were a of PC12 cells was the increased neurite and are PC12 cells, and tyrosine hydroxylase is of the rate-limiting the catecholamine biosynthesis. ERK5 is differentiation of PC12 cells by we ERK5 is involved in differentiation of PC12 cells by tyrosine hydroxylase expression. PC12 cells were in the of NGF or Bt2cAMP a tyrosine hydroxylase protein was hydroxylase gene promoter contains transcription factor J. Biol. Chem. 2006; Full Text Full Text PDF PubMed Scopus Google and of the transcription and cAMP element-binding protein involved in the tyrosine hydroxylase transcription are to by ERK5 (6.Morimoto H. Kondoh K. Nishimoto S. Terasawa K. Nishida E. J. Biol. Chem. 2007; 282: 35449-35456Abstract Full Text Full Text PDF PubMed Scopus (80) Google Scholar, 9.Cavanaugh J.E. Eur. J. Biochem. 2004; 271: 2056-2059Crossref PubMed Scopus (72) Google Scholar, F.L. Heerssen H.M. Bhattacharyya A. Klesse L. Lin M.Z. Segal R.A. Nat. Neurosci. 2001; 4: 981-988Crossref PubMed Scopus (384) Google Scholar). PC12 cells were with the tyrosine hydroxylase gene promoter to the gene to the promoter Both NGF and Bt2cAMP increased the promoter and these were by However, or not the promoter activity in the or of ERK1/2 but not ERK5 is activation of tyrosine hydroxylase The tyrosine hydroxylase protein expression was tyrosine hydroxylase expression was by ERK5 signaling tyrosine hydroxylase was by NGF or Bt2cAMP the of or was However, tyrosine hydroxylase protein expression was when ERK5 and ERK1/2 signaling was by the interfering and NGF-induced tyrosine hydroxylase were by in the of and by in the of tyrosine hydroxylase were by in the of and by in the of Taking these results together, it is that ERK5 regulates or of tyrosine hydroxylase, in with ERK1/2. the role of ERK5 in of tyrosine hydroxylase protein in PC12 cells with or were with NGF or Bt2cAMP a in the or of and with to block tyrosine hydroxylase protein expression to by the of both ERK5 and ERK1/2 in with that of NGF and with Bt2cAMP with tyrosine hydroxylase protein by NGF or Bt2cAMP was and not by However, in of but not Bt2cAMP, the tyrosine hydroxylase protein was in the of In the of induced a in tyrosine hydroxylase The was by to block MEK5 tyrosine hydroxylase was in a manner in the of at and at and tyrosine hydroxylase by NGF was and to to at However, in the of tyrosine hydroxylase was in but was the in the of tyrosine hydroxylase was at and at results that ERK5 is involved in stabilization of tyrosine hydroxylase in the of tyrosine hydroxylase protein in PC12 PC12 cells were with or the cells were with or 30 and with NGF or Bt2cAMP with tyrosine hydroxylase was examined by PC12 cells were with or or 30 and with NGF with or tyrosine hydroxylase was examined by hydroxylase has at phosphorylation at and and the phosphorylation was induced by kinases protein kinase J. Biol. Chem. 2004; Full Text Full Text PDF PubMed Scopus Google Scholar). has been that tyrosine hydroxylase at is phosphorylated by ERK1/2 or its kinase and this phosphorylation is important stabilization of tyrosine hydroxylase J. Biol. Chem. 2004; Full Text Full Text PDF PubMed Scopus Google Scholar). For this we to the that of tyrosine hydroxylase protein is by phosphorylation by ERK5 or its NGF induced phosphorylation of tyrosine hydroxylase at in a manner at at and at 30 the the of Bt2cAMP was at at and at 30 Next, we examined ERK5 was the NGF-induced phosphorylation of tyrosine the NGF-induced phosphorylation was not at by of the dominant-negative ERK5 attenuated this phosphorylation In on the NGF-induced phosphorylation of tyrosine hydroxylase results that ERK5 is essential stabilization of tyrosine hydroxylase but that this is of the phosphorylation at In this study, we the physiological role of ERK5 in differentiation of PC12 cells both and the that ERK5 activation was NGF-induced neurite outgrowth and stabilization of the enzyme tyrosine hydroxylase, whereas ERK1/2 activity is neurite gene expression of tyrosine hydroxylase, and phosphorylation of the enzyme at cAMP only ERK1/2 phosphorylation that is neurite outgrowth and gene expression of tyrosine hydroxylase has been that and block MEK5 well MEK1/2 S. Nishida E. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). have that signaling is to these Z. E. S. G. H. G. H. J. 2007; PubMed Scopus Google or that are to block ERK5 phosphorylation E. E. S. A. S. J. PubMed Scopus Google Scholar, J. C. Dixon J. 2001; PubMed Scopus Google Scholar). the used in this study, we that these selectively ERK1/2 signaling and In contrast, we that BIX02188 and BIX02189, ERK5 phosphorylation ERK1/2 phosphorylation to the role of ERK5 ERK1/2. NGF and induced the of both ERK5 and ERK1/2, cAMP only induced ERK1/2 phosphorylation is with the that ERK5 activity in cortical J.E. J. S. C. Xia Z. J. Neurosci. 2001; PubMed Google and that cAMP regulates ERK5 activity S. Cobb M.H. Cell. Biol. 2006; 26: PubMed Scopus Google Scholar, Y. Y. S. A. H. Cell. Signal. PubMed Scopus Google Scholar). cAMP a ERK1/2 the ERKs examined in this ERK5 is survival by NGF and J.E. Eur. J. Biochem. 2004; 271: 2056-2059Crossref PubMed Scopus (72) Google Scholar, F.L. Heerssen H.M. Bhattacharyya A. Klesse L. Lin M.Z. Segal R.A. Nat. Neurosci. 2001; 4: 981-988Crossref PubMed Scopus (384) Google or by growth (10.Kato Y. Tapping R.I. Huang S. Watson M.H. Ulevitch R.J. Lee J.D. Nature. 1998; 395: 713-716Crossref PubMed Scopus (360) Google Scholar). However, the physiological role of ERK5 in differentiation by has been a have been reported that was by ERK5 in X. S. Nishida E. EMBO Rep. PubMed Scopus Google and that ERK5 is of cortical L. G. Wang Y. Sakagami H. Xu Xia Z. Proc. Natl. Acad. Sci. U.S.A. 2006; PubMed Scopus Google Scholar). In this study, we the that ERK5 is essential neurite outgrowth induced by NGF in PC12 cells and stabilization of the gene tyrosine ERK5 activity is not to neurite outgrowth in this that signaling are neural differentiation, the role of ERK1/2 pathway is to the of transcription of that are the differentiation A. Curr. Opin. PubMed Scopus Google Scholar). it has been that differentiation by ERK5 results activation of transcription nuclear and are or activated by ERK5 J.E. Eur. J. Biochem. 2004; 271: 2056-2059Crossref PubMed Scopus (72) Google Scholar, F.L. Heerssen H.M. Bhattacharyya A. Klesse L. Lin M.Z. Segal R.A. Nat. Neurosci. 2001; 4: 981-988Crossref PubMed Scopus (384) Google Scholar, L. Cavanaugh J.E. Wang Y. Sakagami H. Mao Z. Xia Z. Proc. Natl. Acad. Sci. U.S.A. 2003; 100: 8532-8537Crossref PubMed Scopus (144) Google Scholar, S. Nishida E. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar, J. S. S. E. C. J. A. R.A. J. 2006; PubMed Scopus Google Scholar, K. Wang Y. H. Wang Xia Z. J. Cell Biol. 2007; PubMed Scopus Google Scholar, Y. Tapping R.I. J. Ulevitch R.J. Lee J.D. EMBO J. 1997; PubMed Scopus Google Scholar). these transcription are that differentiation by ERK5. ERK1/2 activity was tyrosine hydroxylase gene expression The tyrosine hydroxylase promoter transcription and and the activity of is by ERK5 in to ERK1/2. However, activation of the tyrosine hydroxylase promoter was not in this ERK5 activity was essential of tyrosine hydroxylase protein action involved ERK1/2 because both ERK5 and ERK1/2 signaling was to up-regulation of the tyrosine hydroxylase protein these is that ERK5 regulates the of tyrosine hydroxylase hydroxylase is the rate-limiting enzyme catecholamine and is important the catecholamine we the of ERK5 to tyrosine hydroxylase has been that tyrosine hydroxylase phosphorylation at is important its and that ERK1/2 or its kinase this J. Biol. Chem. 2004; Full Text Full Text PDF PubMed Scopus Google Scholar). phosphorylation the of tyrosine hydroxylase to that is to or we to the role of ERK5 in phosphorylation of tyrosine we that NGF increased its phosphorylation at it was only by MEK1/2 but not that this phosphorylation was ERK1/2-dependent it is that stabilization of tyrosine hydroxylase by ERK5 on this phosphorylation However, we the that ERK5 that its that ERK5 the of the A. S. and J. S. and that the protein stabilization by ERK5 is to not tyrosine but a Recently, it was that glycogen synthase kinase-3β was by phosphorylation at by ERK5 and that a of the was of in of A. C. C. Cell. Signal. PubMed Scopus Google Scholar). of by ERK5 is an the of ERK5 the in protein In this study, cAMP by ERK5 phosphorylation However, tyrosine hydroxylase protein was by both ERK5 and ERK1/2 signaling in of NGF to this is that ERK5 kinase activity is stabilization of tyrosine is that this a ERK5 and ERK1/2. Recently, it was that the ERK5 carboxyl terminus was phosphorylated by the amino-terminal half of ERK5 that the kinase domain (6.Morimoto H. Kondoh K. Nishimoto S. Terasawa K. Nishida E. J. Biol. Chem. 2007; 282: 35449-35456Abstract Full Text Full Text PDF PubMed Scopus (80) Google Scholar). The amino-terminal half of ERK5 shares homology with ERK1/2. the amino-terminal half of ERK5 phosphorylation of the ERK5 carboxyl it that ERK1/2 the ERK5 carboxyl ERK5 transcription activity of ERK5 kinase In ERK5 a with cAMP the ERK5 signaling pathway by phosphorylation of the ERK5 carboxyl terminus by ERK1/2. has been that ERK5 activation by NGF and in PC12 cells is by the dominant-negative mutant of S. Nishida E. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). In a caused ERK5 activation in PC12 cells S. Nishida E. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google is growth factor signaling to ERK5. ERK5 phosphorylation was not by and not ERK5 in HeLa cells (10.Kato Y. Tapping R.I. Huang S. Watson M.H. Ulevitch R.J. Lee J.D. Nature. 1998; 395: 713-716Crossref PubMed Scopus (360) Google Scholar). In cortical neurons, ERK5 activation by was not by Y. Xia Z. J. Biol. Chem. 2006; Full Text Full Text PDF PubMed Scopus Google Scholar). In cells, signaling or to ERK5 not and S. M.J. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). In study, NGF ERK5 ERK1/2 phosphorylation in the was was not ERK5 phosphorylation ERK1/2 phosphorylation was by this mutant Y. Y. S. A. H. Cell. Signal. PubMed Scopus Google Scholar). In that was involved in ERK5 activation S. Nishida E. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google the ERK5 kinase was protein a ERK5 However, the protein is a well ERK1/2 In ERK5 a with it is that ERK1/2 was in ERK5 and the results were by ERK1/2 activity in Taking these results together, we that is not NGF or ERK5 activation in PC12 In of of was involved in activation of ERK5 in cortical Y. Xia Z. J. Biol. Chem. 2006; Full Text Full Text PDF PubMed Scopus Google Scholar). However, that is activated by protein activated by cAMP ERK5 in protein kinase J. J.D. Nature. PubMed Scopus Google Scholar). In cAMP activated protein kinase and tyrosine kinase in PC12 cells Y. K. J. Cell Sci. 2004; PubMed Scopus Google Scholar). However, activated by not ERK5 phosphorylation Y. Y. S. A. H. Cell. Signal. PubMed Scopus Google Scholar). In this study, ERK5 was not activated by a cAMP analog of activating activated ERK5 in PC12 cells Y. Y. S. A. H. Cell. Signal. PubMed Scopus Google not activity in PC12 cells by Y. K. J. Cell Sci. 2004; PubMed Scopus Google Scholar). results that is not a ERK5 activation in PC12 In this study, we two of an of and of that activation of by NGF H. Nature. 1998; PubMed Scopus Google Scholar, S. K. Y. J. Cell Biol. 2007; PubMed Scopus Google Scholar). results is not ERK5 activation by NGF and it is that the ERK5 activation in cortical Y. Xia Z. J. Biol. Chem. 2006; Full Text Full Text PDF PubMed Scopus Google has been that a is essential the ERK5 activation by NGF in PC12 cells C. J. Cell Biol. 2007; PubMed Scopus Google it a signaling pathway and of small ERK5 in cells in In we the that ERK5 neurite outgrowth and tyrosine hydroxylase stabilization in PC12 The of ERK5 ERK5 and ERK1/2, and physiological role of ERK5 in and neurite outgrowth with BIX02188 and Xia of and Nishida PC12 cells that were with at of of