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Ikegami Y, Ijima H. Development of heparin-conjugated nanofibers and a novel biological signal by immobilized growth factors for peripheral nerve regeneration. J Biosci Bioeng 2019; 129:354-362. [PMID: 31601468 DOI: 10.1016/j.jbiosc.2019.09.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 08/12/2019] [Accepted: 09/05/2019] [Indexed: 11/29/2022]
Abstract
Aligned fibers have been used as a scaffold of nerve guidance conduit owing to their guiding function of neural cells for peripheral nerve regeneration. However, the recovery performance of nerve guidance conduits using aligned fibrous scaffold is insufficient, and further improvements in scaffold function is required for promoting regeneration. In this study, we developed aligned heparin-conjugated fibers and supplied a biological signal to neural cells by the growth factors immobilized through heparin. Results indicated that neural model cells (PC12 cells) were cultured well on the scaffold without inhibiting cell adhesion by heparin conjugation and exhibited more vigorous cell proliferation than in a heparin-free condition. The cells extended their neurites along the fiber direction. Furthermore, PC12 cells on the heparin-conjugated fibrous scaffold pre-exposed to a nerve growth factor solution sprouted more neurites compared to those of heparin-free condition. These results verified that our scaffold exhibited high biocompatibility to neural cells and could maintain an effective local concentration of growth factors on the scaffold surface. Therefore, aligned heparin-conjugated fibers are promising scaffolds of nerve guidance conduits for promoting peripheral nerve regeneration by the combinatorial effect of topological and biological signals.
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Affiliation(s)
- Yasuhiro Ikegami
- Department of Chemical Engineering, Faculty of Engineering, Graduate School, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Hiroyuki Ijima
- Department of Chemical Engineering, Faculty of Engineering, Graduate School, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
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2
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Hensel N, Stockbrügger I, Rademacher S, Broughton N, Brinkmann H, Grothe C, Claus P. Bilateral crosstalk of rho- and extracellular-signal-regulated-kinase (ERK) pathways is confined to an unidirectional mode in spinal muscular atrophy (SMA). Cell Signal 2013; 26:540-8. [PMID: 24316236 DOI: 10.1016/j.cellsig.2013.11.027] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 11/15/2013] [Accepted: 11/26/2013] [Indexed: 10/26/2022]
Abstract
Rho-kinase (ROCK) as well as extracellular signal regulated kinase (ERK) control actin cytoskeletal organization thereby regulating dynamic changes of cellular morphology. In neurons, motility processes such as axonal guidance and neurite outgrowth demand a fine regulation of upstream pathways. Here we demonstrate a bilateral ROCK-ERK information flow in neurons. This process is shifted towards an unidirectional crosstalk in a model of the neurodegenerative disease Spinal Muscular Atrophy (SMA), ultimately leading to neurite outgrowth dysregulations. As both pathways are of therapeutic relevance for SMA, our results argue for a combinatorial ROCK/ERK-targeting as a future treatment strategy.
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Affiliation(s)
- Niko Hensel
- Institute of Neuroanatomy, Hannover Medical School, 30625 Hannover, Germany; Center for Systems Neuroscience (ZSN), 30559 Hannover, Germany
| | - Inga Stockbrügger
- Institute of Neuroanatomy, Hannover Medical School, 30625 Hannover, Germany
| | - Sebastian Rademacher
- Institute of Neuroanatomy, Hannover Medical School, 30625 Hannover, Germany; Center for Systems Neuroscience (ZSN), 30559 Hannover, Germany
| | - Natasha Broughton
- Institute of Neuroanatomy, Hannover Medical School, 30625 Hannover, Germany
| | - Hella Brinkmann
- Institute of Neuroanatomy, Hannover Medical School, 30625 Hannover, Germany
| | - Claudia Grothe
- Institute of Neuroanatomy, Hannover Medical School, 30625 Hannover, Germany; Center for Systems Neuroscience (ZSN), 30559 Hannover, Germany
| | - Peter Claus
- Institute of Neuroanatomy, Hannover Medical School, 30625 Hannover, Germany; Center for Systems Neuroscience (ZSN), 30559 Hannover, Germany; Niedersachsen Research Network on Neuroinfection (N-RENNT), Germany.
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3
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The role of Src protein in the process formation of PC12 cells induced by the proteasome inhibitor MG-132. Neurochem Int 2013; 63:413-22. [DOI: 10.1016/j.neuint.2013.07.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 07/05/2013] [Accepted: 07/23/2013] [Indexed: 11/20/2022]
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4
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Baranova LA, Emel’yanova VP, Zhornik EV, Minov AM, Naumenko LV, Volotovskii ID. Cloning and analysis of coding cDNA sequence of human leukocyte Csk tyrosine kinase under normal conditions and in choroidal melanoma. BIOL BULL+ 2008. [DOI: 10.1134/s1062359008060022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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5
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Dey N, Howell BW, De PK, Durden DL. CSK negatively regulates nerve growth factor induced neural differentiation and augments AKT kinase activity. Exp Cell Res 2005; 307:1-14. [PMID: 15890337 DOI: 10.1016/j.yexcr.2005.02.029] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2004] [Revised: 01/12/2005] [Accepted: 02/10/2005] [Indexed: 11/26/2022]
Abstract
Src family kinases are involved in transducing growth factor signals for cellular differentiation and proliferation in a variety of cell types. The activity of all Src family kinases (SFKs) is controlled by phosphorylation at their C-terminal 527-tyrosine residue by C-terminal SRC kinase, CSK. There is a paucity of information regarding the role of CSK and/or specific Src family kinases in neuronal differentiation. Pretreatment of PC12 cells with the Src family kinase inhibitor, PP1, blocked NGF-induced activation of SFKs and obliterated neurite outgrowth. To confirm a role for CSK and specific isoforms of SFKs in neuronal differentiation, we overexpressed active and catalytically dead CSK in the rat pheochromocytoma cell line, PC12. CSK overexpression caused a profound inhibition of NGF-induced activation of FYN, YES, RAS, and ERK and inhibited neurite outgrowth, NGF-stimulated integrin-directed migration and blocked the NGF-induced conversion of GDP-RAC to its GTP-bound active state. CSK overexpression markedly augmented the activation state of AKT following NGF stimulation. In contrast, kinase-dead CSK augmented the activation of FYN, RAS, and ERK and increased neurite outgrowth. These data suggest a distinct requirement for CSK in the regulation of NGF/TrkA activation of RAS, RAC, ERK, and AKT via the differential control of SFKs in the orchestration of neuronal differentiation.
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Affiliation(s)
- Nandini Dey
- Section of Pediatric Hematology/Oncology, Department of Pediatrics, AFLAC Cancer Center and Blood Disorders Services, Emory University School of Medicine, Atlanta, GA 30022, USA
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6
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Obara Y, Labudda K, Dillon TJ, Stork PJS. PKA phosphorylation of Src mediates Rap1 activation in NGF and cAMP signaling in PC12 cells. J Cell Sci 2004; 117:6085-94. [PMID: 15546918 DOI: 10.1242/jcs.01527] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Recent studies suggest that the tyrosine kinase Src plays an important role in the hormonal regulation of extracellular signal-regulated kinases (ERKs) via cyclic AMP (cAMP). Src has also been proposed to mediate signals downstream of nerve growth factor (NGF). Here, we report that the cAMP-dependent protein kinase A (PKA) induced the phosphorylation of Src at residue serine17 (S17) in multiple cell types including PC12, Hek293, AtT-20 and CHO cells. In PC12 cells, Src phosphorylation on S17 participates in the activation of the small G protein Rap1 by both cAMP and NGF. In these cells, Rap1 is required for cAMP/PKA signaling to ERKs and also for the sustained activation of ERKs by NGF. The activation of Rap1 by both cAMP and NGF was blocked by PP2, an inhibitor of Src family kinases, and by a Src mutant incapable of being phosphorylated by PKA (SrcS17A), consistent with the requirement of PKA phosphorylation of Src at S17 in these actions. PP2 and SrcS17A also inhibited the Rap1-dependent activation of ERKs by both agents. These results strongly indicate that PKA phosphorylation of Src at S17 is essential for cAMP and NGF signaling in PC12 cells and identify PKA as an important downstream target of NGF. PKA phosphorylation of Src may therefore be required for Rap1 activation in PC12 cells.
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Affiliation(s)
- Yutaro Obara
- The Vollum Institute, L474, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
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7
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Clump DA, Clem R, Qian Y, Guappone-Koay A, Berrebi AS, Flynn DC. Protein expression levels of the Src activating protein AFAP are developmentally regulated in brain. JOURNAL OF NEUROBIOLOGY 2003; 54:473-85. [PMID: 12532398 DOI: 10.1002/neu.10143] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The Src family of nonreceptor tyrosine kinases plays an important role in modulating signals that affect growth cone extension, neuronal differentiation, and brain development. Recent reports indicate that the Src SH2/SH3 binding partner AFAP-110 has the capacity to modulate actin filament integrity as a cSrc activating protein and as an actin filament bundling protein. Both AFAP-110 and a brain specific isoform called AFAP-120 (collectively referred to as AFAP) exist at high levels in chick embryo brain. We sought to identify the localization of AFAP in mouse brain in order to identify its expression pattern and potential role as a cellular modulator of Src family kinase activity and actin filament integrity in the brain. In E16 mouse embryos, AFAP expression levels were very high and concentrated in the olfactory bulb, cortex, forebrain, cerebellum, and various peripheral sensory structures. In P3 mouse pups, overall expression was reduced compared to E16 embryos, and AFAP was found primarily in olfactory bulb, cortex, and cerebellum. AFAP expression levels were significantly reduced in adult mice, with high expression levels only detected in the olfactory bulb. Western blot analysis indicated that concentrated expression of AFAP correlates well with the AFAP-120 isoform, which appears to be a splice variant of AFAP-110. As the expression pattern of AFAP overlaps with the reported expression patterns of cSrc and Fyn, we hypothesize that AFAP is positioned to modulate signal transduction cascades that direct activation of these nonreceptor tyrosine kinases and concomitant cellular changes that occur in actin filaments during brain development.
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Affiliation(s)
- David A Clump
- The Mary Babb Randolph Cancer Center and the Department of Microbiology, Immunology and Cell Biology, West Virginia University, Morgantown, West Virginia 26506-9300, USA
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8
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Abstract
Nerve growth factor (NGF) was discovered 50 years ago as a molecule that promoted the survival and differentiation of sensory and sympathetic neurons. Its roles in neural development have been characterized extensively, but recent findings point to an unexpected diversity of NGF actions and indicate that developmental effects are only one aspect of the biology of NGF. This article considers expanded roles for NGF that are associated with the dynamically regulated production of NGF and its receptors that begins in development, extends throughout adult life and aging, and involves a surprising variety of neurons, glia, and nonneural cells. Particular attention is given to a growing body of evidence that suggests that among other roles, endogenous NGF signaling subserves neuroprotective and repair functions. The analysis points to many interesting unanswered questions and to the potential for continuing research on NGF to substantially enhance our understanding of the mechanisms and treatment of neurological disorders.
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Affiliation(s)
- M V Sofroniew
- Department of Neurobiology and Brain Research Institute, University of California Los Angeles, Los Angeles, California 90095-1763, USA.
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9
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Encinas M, Tansey MG, Tsui-Pierchala BA, Comella JX, Milbrandt J, Johnson EM. c-Src is required for glial cell line-derived neurotrophic factor (GDNF) family ligand-mediated neuronal survival via a phosphatidylinositol-3 kinase (PI-3K)-dependent pathway. J Neurosci 2001; 21:1464-72. [PMID: 11222636 PMCID: PMC6762937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
Abstract
The glial cell line-derived neurotrophic factor (GDNF) family ligands (GFLs), consisting of GDNF, neurturin, persephin, and artemin, signal via a multicomponent complex composed of Ret tyrosine kinase and the glycosyl-phosphatidylinositol (GPI)-anchored coreceptors GFRalpha1-alpha4. In previous work we have demonstrated that the localization of Ret to membrane microdomains known as lipid rafts is essential for GDNF-induced downstream signaling, differentiation, and neuronal survival. Moreover, we have found that Ret interacts with members of the Src family kinases (SFK) only when it is localized to these microdomains. In the present work we show by pharmacological and genetic approaches that Src activity was necessary to elicit optimal GDNF-mediated signaling, neurite outgrowth, and survival. In particular, p60Src, but not the other ubiquitous SFKs, Fyn and Yes, was responsible for the observed effects. Moreover, Src appeared to promote neuronal survival via a phosphatidylinositol-3 kinase (PI-3K)-dependent pathway because the PI-3K inhibitor LY294002 prevented GFL-mediated neuronal survival and prevented activated Src-mediated neuronal survival. In contrast, the inhibition of Src activity had no effects on NGF-mediated survival, indicating that the requirement for Src was selective for GFL-mediated neuronal survival. These data confirm the importance of protein-protein interactions between Ret and raft-associated proteins in the signaling pathways elicited by GDNF, and the data implicate Src as one of the major signaling molecules involved in GDNF-mediated bioactivity.
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Affiliation(s)
- M Encinas
- Grup de Neurobiologia Molecular, Departament de Ciències Mèdiques Basiques, Facultat de Medicina, Universitat de Lleida, 25198 Lleida, Spain
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10
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Dobashi Y, Shoji M, Kitagawa M, Noguchi T, Kameya T. Simultaneous suppression of cdc2 and cdk2 activities induces neuronal differentiation of PC12 cells. J Biol Chem 2000; 275:12572-80. [PMID: 10777547 DOI: 10.1074/jbc.275.17.12572] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The involvement of cdc2 and cdk2 during neuronal differentiation in rat pheochromocytoma PC12 cells was examined. When PC12 cells were cultured with nerve growth factor (NGF), expression of cdc2 decreased significantly after day 5, while expression of cdk2 decreased gradually after day 7. Cells overexpressing cdc2 or cdk2 were resistant to NGF-induced differentiation and growth suppression, and maintained high cdc2 or cdk2 kinase activity, respectively, during NGF treatment. In contrast, the NGF-treated parental cells showed a marked decline in these kinase activities after day 3. When PC12 cells were treated with specific inhibitors of cdc2/cdk2 (butyrolactone-I, olomoucin), they showed marked neurite extension and up-regulation of microtubule-associated protein 2 expression. In addition, treatment with mixtures of antisense oligonucleotides for cdc2 and cdk2 resulted in down-regulation of both cdc2 and cdk2 kinase activities as well as significant neurite outgrowth and up-regulation of microtubule-associated protein 2 expression. However, neurite outgrowth was not observed in cells treated with either single antisense oligonucleotide, or antisense cdc2 + cdk4 or cdk2 + cdk4 oligonucleotide mixtures. These results suggest that simultaneous down-regulation of cdc2 and cdk2 activity is sufficient and necessary for neuronal differentiation in PC12 cells.
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Affiliation(s)
- Y Dobashi
- Department of Pathology, Kitasato University School of Medicine, 1-15-1, Kitasato, Sagamihara, Kanagawa 228-8555, Japan.
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11
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Malek RL, Nie Z, Ramkumar V, Lee NH. Adenosine A(2A) receptor mRNA regulation by nerve growth factor is TrkA-, Src-, and Ras-dependent via extracellular regulated kinase and stress-activated protein kinase/c-Jun NH(2)-terminal kinase. J Biol Chem 1999; 274:35499-504. [PMID: 10585422 DOI: 10.1074/jbc.274.50.35499] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have shown previously that nerve growth factor (NGF) down-regulates adenosine A(2A) receptor (A(2A)AR) mRNA in PC12 cells. To define cellular mechanisms that modulate A(2A)AR expression, A(2A)AR mRNA and protein levels were examined in three PC12 sublines: i) PC12nnr5 cells, which lack the high affinity NGF receptor TrkA, ii) srcDN2 cells, which overexpress kinase-defective Src, and iii) 17.26 cells, which overexpress a dominant-inhibitory Ras. In the absence of functional TrkA, Src, or Ras, NGF-induced down-regulation of A(2A)AR mRNA and protein was significantly impaired. However, regulation of A(2A)AR expression was reconstituted in PC12nnr5 cells stably transfected with TrkA. Whereas NGF stimulated the mitogen-activated protein kinases p38, extracellular regulated kinase 1 and 2 (ERK1/ERK2), and stress-activated protein kinase/c-Jun NH(2)-terminal kinase (SAPK/JNK) in PC12 cells, these kinases were activated only partially or not at all in srcDN2 and 17.26 cells. Inhibiting ERK1/ERK2 with PD98059 or inhibiting SAPK/JNK by transfecting cells with a dominant-negative SAPKbeta/JNK3 mutant partially blocked NGF-induced down-regulation of A(2A)AR expression in PC12 cells. In contrast, inhibiting p38 with SB203580 had no effect on the regulation of A(2A)AR mRNA and protein levels. Treating SAPKbeta/JNK3 mutant-transfected PC12 cells with PD98059 completely abolished the NGF-induced decrease in A(2A)AR mRNA and protein levels. These results reveal a role for ERK1/ERK2 and SAPK/JNK in regulating A(2A)AR expression.
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Affiliation(s)
- R L Malek
- Department of Molecular and Cellular Biology, The Institute for Genomic Research, Rockville, Maryland 20850, USA
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12
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Rane SG. Ion channels as physiological effectors for growth factor receptor and Ras/ERK signaling pathways. ADVANCES IN SECOND MESSENGER AND PHOSPHOPROTEIN RESEARCH 1999; 33:107-27. [PMID: 10218116 DOI: 10.1016/s1040-7952(99)80007-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Affiliation(s)
- S G Rane
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907, USA
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13
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Abstract
Src family protein tyrosine kinases are activated following engagement of many different classes of cellular receptors and participate in signaling pathways that control a diverse spectrum of receptor-induced biological activities. While several of these kinases have evolved to play distinct roles in specific receptor pathways, there is considerable redundancy in the functions of these kinases, both with respect to the receptor pathways that activate these kinases and the downstream effectors that mediate their biological activities. This chapter reviews the evidence implicating Src family kinases in specific receptor pathways and describes the mechanisms leading to their activation, the targets that interact with these kinases, and the biological events that they regulate.
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Affiliation(s)
- S M Thomas
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02115, USA.
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14
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Kuo SS, Armanini MP, Phillips HS, Caras IW. Csk and BatK show opposite temporal expression in the rat CNS: consistent with its late expression in development, BatK induces differentiation of PC12 cells. Eur J Neurosci 1997; 9:2383-93. [PMID: 9464932 DOI: 10.1111/j.1460-9568.1997.tb01655.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BatK is a second member of the Csk family of regulatory kinases that phosphorylate a key inhibitory tyrosine on Src family kinases, leading to down-regulation. To investigate the roles of BatK and Csk, both of which are expressed in the brain, we compared their temporal expression patterns during development of the central nervous system (CNS) in rats. BatK mRNA is undetectable at embryonic day 12 (E12), appears in the developing nervous system at approximately E15, and its expression progressively increases up to the time of birth, thereafter remaining high throughout the adult brain. In striking contrast, Csk is highly expressed throughout embryonic development and remains high in the CNS until birth. It is then dramatically down-regulated in the adult brain except in the olfactory bulb. BatK and Csk thus exhibit complementary temporal expression patterns. Since BatK expression correlates with late-stage development and terminal differentiation, we speculated that it might be involved in regulating neuronal differentiation. Using PC12 cells as a model system, we show that overexpression of BatK is sufficient to induce neurite outgrowth in the absence of nerve growth factor. Further, overexpression of BatK activates the mitogen-activated protein kinase cascade. We propose a model suggesting that, despite overlapping in vitro activities, BatK and Csk regulate different targets in vivo and have different functions during and after neuronal development, BatK being the dominant regulator of Src kinases in the fully differentiated adult brain.
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Affiliation(s)
- S S Kuo
- Department of Neuroscience, Genentech, Inc., South San Francisco, CA 94080, USA
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15
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Malosio ML, De Curtis I. Tyrosine phosphorylation induced by integrin-mediated adhesion of retinal neurons to laminin. Int J Dev Neurosci 1996; 14:269-81. [PMID: 8842804 DOI: 10.1016/0736-5748(96)00013-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Integrin alpha 6 beta 1 is a laminin receptor involved in adhesion and neurite extension of retinal neurons on laminin. The present study was carried out to understand some of the intracellular mechanisms which allow integrin-mediated neurite extension on laminin in primary neuronal cultures. Both integrin-mediated adhesion to laminin and antibody-induced integrin clustering resulted in the increased tyrosine phosphorylation of a 120 kDa polypeptide which was identified as the focal adhesion kinase. The kinetics of phosphorylation and dephosphorylation of this kinase were dramatically different in neurons plated on laminin, than in neurons in which the receptors were clustered with anti-integrin antibodies. To look at possible interactions of the focal adhesion kinase with integrins, we made use of sucrose velocity gradients, which have allowed the identification of a large complex containing the alpha 6 beta 1 laminin receptor. Analysis of the gradients showed that the focal adhesion kinase was not associated with the integrin receptors under these experimental conditions, while about 26% of the c-Src kinase codistributed with the integrin receptor complex, and showed a molecular size and a distribution similar to that of a 59 kDa phosphoprotein comigrating with the alpha 6 beta 1 receptor. Our results suggest that integrin-induced tyrosine phosphorylation is an early intracellular event during neuronal adhesion, and that the integrin-mediated increase in tyrosine phosphorylation of the focal adhesion kinase is not sufficient per se for the induction of neurite outgrowth. Furthermore, our data indicate that Src kinase may be involved in integrin-mediated neuronal interactions with laminin.
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Affiliation(s)
- M L Malosio
- Department of Biological and Technological Research (DIBIT), S. Raffaele Scientific Institute, Milano, Italy
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16
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Abstract
The combination of nerve growth factor (NGF) and phorbol 12-myristate 13-acetate (PMA) rapidly induced the locomotion of PC12 cells by sequentially stimulating lamellar spreading, ruffling with pinocytosis, and polarization by retraction from the substratum. During migration, cells acquired long processes as a result of several undisrupted cell-substratum attachment points. The effect of NGF on PC12 migration was blocked by K-252a, a selective inhibitor of the trk family of receptor tyrosine kinases. When PMA was added to cells expressing pp60v-src, the cells displayed the same morphological behavior as they did with NGF and PMA addition. Activated ras only partially substituted for the effects of NGF; but, when ras was inhibited, the number of migrating cells decreased significantly due to a defect in spreading and retraction. Expression of an activated form of rac stimulated spontaneous growth of lamellipodia and enhanced cell migration in response to PMA. Expression of a dominant negative form of rac inhibited cell spreading and motility. Also, as a later effect, rac-inhibited cells extended much shorter neurites than wild type cells in response to NGF alone. These results indicate that the cytoarchitectural changes induced by NGF and PMA in PC12 cells are mediated by src, ras, and rac. Whereas ras and rac activation affect lamellipodia extension and retraction but not pinocytotic ruffling, src activation is involved in all three events.
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Affiliation(s)
- Z F Altun-Gultekin
- Department of Neurology and Neuroscience, Cornell University Medical College, NY 10021, USA
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17
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Rusanescu G, Qi H, Thomas SM, Brugge JS, Halegoua S. Calcium influx induces neurite growth through a Src-Ras signaling cassette. Neuron 1995; 15:1415-25. [PMID: 8845164 DOI: 10.1016/0896-6273(95)90019-5] [Citation(s) in RCA: 221] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We find that calcium influx through voltage-dependent calcium channels causes extensive neurite outgrowth in PC12 cells. The calcium signal transduction pathway promoting neurite outgrowth causes the rapid activation of protein tyrosine kinases, which include Src. Protein tyrosine phosphorylation results in the formation of an Shc/Grb2 complex, leading to Ras activation, MAP kinase activation, and the subsequent induction of the immediate early gene NGFI-A. Protein tyrosine phosphorylation, gene induction, and neurite outgrowth are inhibited by the expression of dominant negative forms of both Src and Ras, indicating a requirement for both proto-oncoproteins in calcium signaling. Our results suggest that a signaling cassette which includes Src and Ras is likely to underlie a broad range of calcium of actions in the nervous system.
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Affiliation(s)
- G Rusanescu
- Department of Neurobiology and Behavior, State University of New York at Stony Brook 11794-5230, USA
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18
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Buensuceso C, Rogers MV. A 56,000 Mr phosphoseryl protein in PC12 cell lysates strongly associates with protein-A sepharose beads and was observed in immune complex kinase assays for PP60c-src. Cell Signal 1995; 7:765-71. [PMID: 8593245 DOI: 10.1016/0898-6568(95)02002-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Using an immune complex kinase assay to measure pp60c-src kinase activity, we have identified a 56,000 Mr protein (p56) from PC12 cell lysates that co-purified with pp60c-src by strong association with protein-A sepharose beads. The p56 protein was strongly phosphorylated on serine but no tyrosine or threonine phosphorylation was evident. However, pp60c-src was strongly phosphorylated on tyrosine, weakly phosphorylated on serine with no observed threonine phosphorylation. P56 was not a proteolytic breakdown product of pp60c-src, since it was neither tyrosine phosphorylated nor was it recognized by anti-src antibody. P56 was also not recognised by other antibodies to 56kD signalling molecules such as p56lck. The identify of p56 awaits further investigation but its appearance in immunoprecipitates of pp60c-src using protein-A sepharose beads is of interest but complicates the the interpretation of results from immune complex kinase assays in PC12 cells.
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Affiliation(s)
- C Buensuceso
- Section of Molecular Pharmacology, Wellcome Research Laboratories, Beckenham, Kent, England
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19
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Misra-Press A, Rim CS, Yao H, Roberson MS, Stork PJ. A novel mitogen-activated protein kinase phosphatase. Structure, expression, and regulation. J Biol Chem 1995; 270:14587-96. [PMID: 7782322 DOI: 10.1074/jbc.270.24.14587] [Citation(s) in RCA: 193] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Mitogen-activated protein (MAP) kinase lies at the convergence of various extracellular ligand-mediated signaling pathways. It is activated by the dual-specificity kinase, MAP kinase kinase or MEK. MAP kinase inactivation is mediated by dephosphorylation via specific MAP kinase phosphatases (MKPs). One MKP (MKP-1 (also known as 3CH134, Erp, or CL100)) has been reported to be expressed in a wide range of tissues and cells. We report the identification of a second widely expressed MKP, termed MKP-2, isolated from PC12 cells. MKP-2 showed significant homology with MKP-1 (58.8% at the amino acid level) and, like MKP-1, displayed vanadate-sensitive phosphatase activity against MAP kinase in vitro. Overexpression of MKP-2 in vivo inhibited MAP kinase-dependent gene transcription in PC12 cells. MKP-2 differed from MKP-1 in its tissue distribution and in its extent of induction by growth factors and agents that induce cellular stress, suggesting that these MKPs may have distinct physiological functions.
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Affiliation(s)
- A Misra-Press
- Vollum Institute, Oregon Health Sciences University, Portland 97201, USA
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20
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Wu CF, Howard BD. K252a-potentiation of EGF-induced neurite outgrowth from PC12 cells is not mimicked or blocked by other protein kinase activators or inhibitors. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 1995; 86:217-26. [PMID: 7656414 DOI: 10.1016/0165-3806(95)00028-c] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Epidermal growth factor (EGF) has recently been shown to cause certain strains of PC12 cells to extend short neurites. This EGF-induced differentiation of PC12 was found to be potentiated by the protein kinase inhibitor, K252a, in that PC12 cells treated with both EGF and K252a extended long branched neurites similar to those induced by nerve growth factor (NGF). As reported here no other protein kinase inhibitor or activator mimicked or blocked the effect of K252a on EGF-induced PC12 differentiation. Cyclic adenosine 3',5'-monophosphate (cAMP) also potentiated EGF-induced neurite outgrowth from PC12 cells, but the mechanism of this potentiation was different from that of K252a. Cells that had been exposed to EGF and then stripped of their neurons extended neurites again when retreated with EGF in the absence of RNA synthesis or when treated with NGF in the absence of RNA synthesis. Thus EGF can prime PC12 cells for either EGF or for NGF, a finding that further suggests that EGF and NGF use similar signaling pathways to induced neuronal differentiation of PC12.
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Affiliation(s)
- C F Wu
- Department of Biological Chemistry, School of Medicine, University of California, Los Angeles 90024, USA
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21
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Rasouly D, Lazarovici P. Staurosporine induces tyrosine phosphorylation of a 145 kDa protein but does not activate gp140trk in PC12 cells. Eur J Pharmacol 1994; 269:255-64. [PMID: 7851502 DOI: 10.1016/0922-4106(94)90094-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Staurosporine, a protein kinase C inhibitor, induces neurite outgrowth in PC12 cells similarly to nerve growth factor (NGF). Since NGF neurotropic effects are transduced by the 'trk' gene product 140 kDa tyrosine kinase receptor, gp140trk, we investigated the role of gp140trk and tyrosine phosphorylations in staurosporine neurotropic effects. A direct correlation between staurosporine neurotropic effects and a novel stimulation of tyrosine phosphorylation of a 145 kDa protein (p145) with the following characteristics has been discovered: (1) Staurosporine specifically induced, among indolcarbazoles-K252a derivatives, in a dose-dependent manner (5-100 nM), p145 tyrosine phosphorylation and neurite outgrowth. (2) Staurosporine-induced p145 tyrosine phosphorylation was selective compared to other neurotropic compounds such as 8-Br-cAMP, acidic and basic fibroblast growth factors and NGF. (3) Staurosporine stimulation of p145 tyrosine phosphorylation gradually increased during the first 8 h of staurosporine treatment coinciding with the initiation of neurotropic effects. (4) K252a, a selective inhibitor of NGF actions, and several tyrphostins did not block staurosporine-induced p145 tyrosine phosphorylation and neurotropic effects. (5) Staurosporine stimulation of p145 tyrosine phosphorylation and neurotropic effects are independent of PKC. (6) Staurosporine did not activate gp140trk-NGF receptor in PC12 cells. The present study proposes staurosporine as a pharmacological tool to study the role of tyrosine phosphorylation pathway(s), such as p145 phosphorylation, in the action of neurotropic agents.
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Affiliation(s)
- D Rasouly
- Department of Pharmacology and Experimental Therapeutics, School of Pharmacy, Faculty of Medicine, Hebrew University of Jerusalem, Israel
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22
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Gamett DC, Cerione RA. Oncogenically activated or ligand-stimulated neu kinase stimulates neurite outgrowth in PC12 cells. FEBS Lett 1994; 351:335-9. [PMID: 7915994 DOI: 10.1016/0014-5793(94)00855-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Retroviral vectors pDOL/NeuN and pDOL/NeuT were used to express normal and transforming rat neu cDNAs in PC12 cells. DOL/NeuT-infected cells exhibited a high frequency of spontaneous neurite outgrowth while DOL/NeuN-infected cells showed neurite outgrowth in the presence of heregulin, a putative ligand for the neu receptor tyrosine kinase. In both cases, neurite outgrowth was preceded by phosphorylation of p185neu and several other cellular proteins. Thus the neu tyrosine kinase can elicit morphological and biochemical changes resembling, but distinct from, those stimulated by NGF, and heregulin stimulates neu to elicit these effects in PC12 cells.
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Affiliation(s)
- D C Gamett
- Department of Pharmacology, New York State College of Veterinary Medicine, Cornell University, Ithaca 14853-6401
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23
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Rane SG, Pollock JD. Fibroblast growth factor-induced increases in calcium currents in the PC12 pheochromocytoma cell line are tyrosine phosphorylation dependent. J Neurosci Res 1994; 38:590-8. [PMID: 7815474 DOI: 10.1002/jnr.490380511] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The PC12 rat pheochromocytoma cell line is widely used to study neuronal differentiation by growth factors. In response to nerve growth factor (NGF) and basic fibroblast growth factor (bFGF), PC12 cells differentiate into sympathetic-like neurons and become electrically excitable. Using whole cell patch-clamp recording, with barium as a charge carrier, we looked at the effects of bFGF on calcium channel expression as reflected by changes in barium current amplitudes normalized to cell membrane area. Similar to the effect reported for NGF, we show that 7 day treatment with bFGF increased the barium current approximately 4-fold. The largest contributor to the increase in barium current with bFGF treatment is a 6-fold increase in the high threshold voltage activated omega-conotoxin sensitive barium current. Smaller increases in current produced by bFGF treatment of PC12 cells are observed for the dihydropyridine sensitive and dihydropyridine/conotoxin insensitive currents. The bFGF-induced increases in barium currents are dependent on tyrosine phosphorylation, since the effects of bFGF are blocked by genistein, a tyrosine kinase inhibitor. This system will ultimately be useful in understanding the signaling pathways that control calcium channel expression in response to growth factors.
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Affiliation(s)
- S G Rane
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana
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24
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Guardavaccaro D, Montagnoli A, Ciotti MT, Gatti A, Lotti L, Di Lazzaro C, Torrisi MR, Tirone F. Nerve growth factor regulates the subcellular localization of the nerve growth factor-inducible protein PC4 in PC12 cells. J Neurosci Res 1994; 37:660-74. [PMID: 8028043 DOI: 10.1002/jnr.490370514] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The immediate early gene (IEG) PC4, which encodes a protein related to gamma interferon, is activated at the onset of the neuronal differentiation induced by nerve growth factor (NGF) in PC12 cells. With an antibody raised to a bacterial beta gal-PC4 fusion protein, the PC4 protein is detected as an immunoreactive molecular species of 49 kDa, whose synthesis is rapidly induced by NGF in parallel with the induction of its mRNA. Immunofluorescence, electron microscopy and subfractionation studies indicate that the PC4 immunoreactivity is localized in the cytoplasm of PC12 cells, where it is increased transiently by NGF within 3 hr of treatment. In addition, the PC4 immunoreactivity presents an NGF-dependent pattern of intracellular localization. In fact, within 3 hr after addition of NGF, PC4 is also significantly expressed on the inner face of the plasma membrane, to which it is physically associated. After longer NGF treatment, PC4 disappears from the plasma membrane and appears in the nucleus, with reduced cytoplasmic expression. Localization in the nucleus is reversed by removal of NGF and closely parallels changes in the state of differentiation of the cell. The existence within the PC4 protein of a consensus sequence for the addition of myristic acid and of a putative sequence for the nuclear localization suggests possible mechanisms for the NGF-dependent redistribution. For an NGF-inducible IEG product, such growth factor-dependent localization of PC4 is a novel type of regulation in the pathways from the NGF receptor to the adjacent membrane proteins and to the nucleus.
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Affiliation(s)
- D Guardavaccaro
- Istituto di Neurobiologia, Consiglio Nazionale delle Richerche, Rome, Italy
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25
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Shackleford GM, Willert K, Wang J, Varmus HE. The Wnt-1 proto-oncogene induces changes in morphology, gene expression, and growth factor responsiveness in PC12 cells. Neuron 1993; 11:865-75. [PMID: 8240810 DOI: 10.1016/0896-6273(93)90116-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The product of the Wnt-1 proto-oncogene is a secreted glycoprotein that is normally produced in regions of the embryonic neural tube. We show here that expression of mouse Wnt-1 cDNA in the rat PC12 pheochromocytoma cell line causes a dramatic conversion from a round to a flat cell morphology. In addition, PC12 cells expressing Wnt-1 (PC12/Wnt-1) fail to extend neurites after treatment with NGF, despite the presence and activation of high affinity NGF receptors encoded by the trk gene and the induction of early response genes. Furthermore, PC12/Wnt-1 cells fail to express several neuron- and chromaffin-specific genes, indicating that PC12/Wnt-1 cells have assumed a new phenotype. Although NGF and FGF utilize similar signal transduction pathways in PC12 cells, only FGF is capable of inducing a morphological response and synthesis of transin mRNA in PC12/Wnt-1 cells.
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Affiliation(s)
- G M Shackleford
- Division of Hematology-Oncology, Children's Hospital Los Angeles, California
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26
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Chakraborty M, Anderson GM, Chakraborty A, Chatterjee D. Accumulation of high level of pp60c-srcN is an early event during GM3-antibody mediated differentiation of neuro-2a neuroblastoma cells. Brain Res 1993; 625:197-202. [PMID: 7506109 DOI: 10.1016/0006-8993(93)91059-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Neuro-2a neuroblastoma cells, when differentiated via a cAMP-dependent pathway by treatment with anti-GM3 monoclonal antibody, accumulated a high level of pp60c-src protein and pp60c-src kinase activity just before the onset of neurite formation. The specific kinase activity of the accumulated c-src protein was found to be comparable to that of normal cerebellar neurons, but was about 6- to 8-fold higher than that of normal astrocytes. These results, and migrations of peptide fragments in the SDS-polyacrylamide gels after V8 proteolysis, strongly indicate the accumulation of the neuron-specific isoform of the c-src protein (pp60c-srcN) in the GM3 antibody-treated Neuro-2a cells. Similar high levels of pp60c-src protein and pp60c-src kinase activity were observed in the Neuro-2a cells differentiated via a cAMP-dependent pathway by treatment with dibutyryl cAMP, but not in the same cell line when differentiated via a cAMP-independent pathway with 5-bromo-2'-deoxyuridine. These results demonstrate that the accumulation of high levels of the neuron-specific isoform of the pp60c-src protein (pp60c-srcN) in the Neuro-2a neuroblastoma cells depends on the specific signal transduction pathway involved during the differentiation of these cells.
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Affiliation(s)
- M Chakraborty
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06511
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27
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Wood KW, Roberts TM. Oncogenes and protein kinases in neuronal growth-factor action. BIOCHIMICA ET BIOPHYSICA ACTA 1993; 1155:133-50. [PMID: 8357824 DOI: 10.1016/0304-419x(93)90002-t] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- K W Wood
- Division of Cellular and Molecular Biology, Dana-Farber Cancer Institute, Boston, MA 02115
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28
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Brady M, Palfrey H. Rapid and sustained phosphorylation of a calmodulin-binding protein (CaM-BP100) in NGF-treated PC12 cells. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(17)46797-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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29
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Grimes M, Zhou J, Li Y, Holtzman D, Mobley WC. Neurotrophin signalling in the nervous system. ACTA ACUST UNITED AC 1993. [DOI: 10.1016/s1044-5765(05)80029-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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30
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Abstract
The study of ubiquitously expressed proto-oncogenes or tumor suppressor genes provided important insights into the second messenger signaling pathways common to neural and non-neural tissues. Therefore, it is expected that the analysis of proto-oncogenes expressed in neural tissues should probe into neurotrophic and neurotransmitter receptors, ion channels and other molecules involved in processes underlying basic physiological functions of the nervous system. This expectation is fulfilled by ample experimental evidence. Using the trk, abl and src families of tyrosine kinase encoded proto-oncogenes, we discuss here new insights into the structural and functional organization of neural tissues gained from the molecular and genetic analyses of these genes and their products. Special attention is given to the description of initial steps of signaling through the Trk receptors in response to neurotrophic factors of the Nerve Growth Factor family. The genetic analysis of the Drosophila abl gene product identified new gene products that interact with the Abl protein. This analysis illuminates the power of Drosophila genetics in dissecting components of a signal transduction pathway. The Src-family of non-receptor type protein-tyrosine kinases is discussed from the point of functional redundancy as revealed by targeted gene disruption and expression studies. The recent progress in the field of proto-oncogenes has been impressive and it is expected that proto-oncogenes will continue to provide valuable tools in the study of the complex signaling pathways that underlie the physiological functions of the central nervous system.
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Affiliation(s)
- M Sudol
- Rockefeller University, New York, NY 10021
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31
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Abstract
The activity of the proto-oncogene encoded c-Src product is tightly regulated in vivo. In recent years, a model has emerged of how this regulation is achieved. In particular, protein kinases and phosphatases that are potential regulators of c-Src activity in the cell cycle have been identified and characterized.
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Affiliation(s)
- S J Taylor
- Section of Biochemistry, Molecular and Cell Biology, Cornell University, Ithaca, New York 14853
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32
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Abstract
New insights into the signal transduction pathways for neuronal growth factors and cell adhesion molecules are affording us a better understanding of the intracellular mechanisms for neuronal differentiation, and of the ways in which the various signals are integrated during this process.
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Affiliation(s)
- K Keegan
- Department of Neurobiology and Behavior, State University of New York, Stony Brook 11794-5230
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33
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Yount GL, Gall CM, White JD. Limbic seizures increase cyclophilin mRNA levels in rat hippocampus. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1992; 14:139-42. [PMID: 1323013 DOI: 10.1016/0169-328x(92)90022-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Limbic seizures lead to dramatic and specific modulation of mRNA levels for many genes in the hippocampus including immediate early, growth factor and neuropeptide genes. In the present study, the influence of hilus lesion (HL)-induced seizures on the abundance of mRNA coding for cyclophilin, a peptide prolyl isomerase, in rat hippocampus was analyzed. By nuclease protection analysis a significant increase in cyclophilin mRNA levels was observed in the hippocampal dentate gyrus/CA1 subfield following HL-induced seizures. The increase began 6 h post-HL, reached a maximum (2.5-fold) at 12 h post-HL and returned to control values by 48 h post-HL. Cyclophilin mRNA levels remained stable in the cerebral cortex throughout the same seizure and post-seizure activity time span.
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Affiliation(s)
- G L Yount
- Department of Medicine, SUNY Stony Brook 11794
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34
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Maness PF, Cox ME. Protein tyrosine kinases in nervous system development. SEMINARS IN CELL BIOLOGY 1992; 3:117-26. [PMID: 1319229 DOI: 10.1016/s1043-4682(10)80021-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Protein tyrosine kinases are important mediators of intracellular signaling during nervous system development. Activation of receptor protein tyrosine kinases by neurotrophic factors are initial events in the development of discrete cell populations. The patterns of expression and characterization of substrates for nonreceptor protein tyrosine kinases indicates that they also play a crucial role in neuronal development. The observed functional redundancy among protein tyrosine kinases and their associated intracellular signaling pathways underscores the need for further characterization of these novel interactions to elucidate the mechanisms regulating nervous system development.
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Affiliation(s)
- P F Maness
- Department of Biochemistry, University of North Carolina School of Medicine, Chapel Hill 27599-7260
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35
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Thomas SM, DeMarco M, D'Arcangelo G, Halegoua S, Brugge JS. Ras is essential for nerve growth factor- and phorbol ester-induced tyrosine phosphorylation of MAP kinases. Cell 1992; 68:1031-40. [PMID: 1312392 DOI: 10.1016/0092-8674(92)90075-n] [Citation(s) in RCA: 605] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Treatment of PC12 cells with nerve growth factor (NGF) induces a rapid increase in tyrosine phosphorylation of multiple cellular proteins. Expression of a dominant inhibitory Ras mutant specifically blocked NGF- and TPA-induced tyrosine phosphorylation of two proteins of approximately 42 and 44 kd. Conversely, expression of an oncogenic variant of Ras induced tyrosine phosphorylation of the same 42 and 44 kd proteins. The 44 kd protein was immunoprecipitated with an antibody directed against extracellular signal-regulated kinase 1/mitogen-activated protein kinase (MAPK) and the 42 kd protein comigrated with a 42 kd MAPK, indicating that at least one and probably both Ras-regulated phosphoproteins are MAPKs. In addition, MAPK activation, as measured by in vitro phosphorylation of myelin basic protein, was also regulated by Ras. Ras was not required for NGF-induced activation of Trk or tyrosine phosphorylation of PLC-gamma 1. Thus, NGF-induced tyrosine phosphorylation occurs both prior to and following Ras action, and Ras plays a critical role in the NGF- and TPA-induced tyrosine phosphorylation of MAPKs.
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Affiliation(s)
- S M Thomas
- Howard Hughes Medical Institute, Department of Microbiology, University of Pennsylvania, Philadelphia 19104
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36
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Wood KW, Sarnecki C, Roberts TM, Blenis J. ras mediates nerve growth factor receptor modulation of three signal-transducing protein kinases: MAP kinase, Raf-1, and RSK. Cell 1992; 68:1041-50. [PMID: 1312393 DOI: 10.1016/0092-8674(92)90076-o] [Citation(s) in RCA: 800] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
p21c-ras plays a critical role in mediating tyrosine kinase-stimulated cell growth and differentiation. However, the pathways through which p21c-ras propagates these signals remain unknown. We report that in PC12 cells, expression of a dominant inhibitory mutant of ras, c-Ha-ras(Asn-17), antagonizes growth factor- and phorbol ester-induced activation of the erk-encoded family of MAP kinases, the 85-92 kd RSKs, and the kinase(s) responsible for hyperphosphorylation of the proto-oncogene product Raf-1. In addition, we find that expression of the activated ras oncogene is sufficient to stimulate these events. These data indicate that ras mediates nerve growth factor receptor and protein kinase C modulation of MAP kinases, RSKs, and Raf-1.
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Affiliation(s)
- K W Wood
- Program in Cell and Developmental Biology, Harvard University, Boston, Massachusetts
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