scholarly journals Binding of Shp2 Tyrosine Phosphatase to FRS2 Is Essential for Fibroblast Growth Factor-Induced PC12 Cell Differentiation

1998 ◽  
Vol 18 (7) ◽  
pp. 3966-3973 ◽  
Author(s):  
Y. R. Hadari ◽  
H. Kouhara ◽  
I. Lax ◽  
J. Schlessinger
Keyword(s):  
Cell Differentiation ◽  
Growth Factor ◽  
Map Kinase ◽  
Fibroblast Growth Factor ◽  
Pc12 Cell ◽  
Tyrosine Phosphatase ◽  
Sh2 Domain ◽  
Fibroblast Growth ◽  
Mitogen Activated Protein ◽  
Docking Protein

ABSTRACT FRS2 is a lipid-anchored docking protein that plays an important role in linking fibroblast growth factor (FGF) and nerve growth factor receptors with the Ras/mitogen-activated protein (MAP) kinase signaling pathway. In this report, we demonstrate that FRS2 forms a complex with the N-terminal SH2 domain of the protein tyrosine phosphatase Shp2 in response to FGF stimulation. FGF stimulation induces tyrosine phosphorylation of Shp2, leading to the formation of a complex containing Grb2 and Sos1 molecules. In addition, a mutant FRS2 deficient in both Grb2 and Shp2 binding induces a weak and transient MAP kinase response and fails to induce PC12 cell differentiation in response to FGF stimulation. Furthermore, FGF is unable to induce differentiation of PC12 cells expressing an FRS2 point mutant deficient in Shp2 binding. Finally, we demonstrate that the catalytic activity of Shp2 is essential for sustained activation of MAP kinase and for potentiation of FGF-induced PC12 cell differentiation. These experiments demonstrate that FRS2 recruits Grb2 molecules both directly and indirectly via complex formation with Shp2 and that Shp2 plays an important role in FGF-induced PC12 cell differentiation.

scholarly journals Mitogen-activated protein kinase activation is insufficient for growth factor receptor-mediated PC12 cell differentiation.

1995 ◽  
Vol 15 (7) ◽  
pp. 3644-3653 ◽  
Author(s):  
R R Vaillancourt ◽  
L E Heasley ◽  
J Zamarripa ◽  
B Storey ◽  
M Valius ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Growth Factor ◽  
Map Kinase ◽  
Pc12 Cells ◽  
Pc12 Cell ◽  
Growth Factor Receptor ◽  
Receptor Activation ◽  
Mitogen Activated Protein ◽  
Map Kinase Pathway ◽  
Kinase Pathway

When expressed in PC12 cells, the platelet-derived growth factor beta receptor (beta PDGF-R) mediates cell differentiation. Mutational analysis of the beta PDGF-R indicated that persistent receptor stimulation of the Ras/Raf/mitogen-activated protein (MAP) kinase pathway alone was insufficient to sustain PC12 cell differentiation. PDGF receptor activation of signal pathways involving p60c-src or the persistent regulation of phospholipase C gamma was required for PC12 cell differentiation. beta PDGF-R regulation of phosphatidylinositol 3-kinase, the GTPase-activating protein of Ras, and the tyrosine phosphatase, Syp, was not required for PC12 cell differentiation. In contrast to overexpression of oncoproteins involved in regulating the MAP kinase pathway, growth factor receptor-mediated differentiation of PC12 cells requires the integration of other signals with the Ras/Raf/MAP kinase pathway.

scholarly journals Somatostatin Activation of Mitogen-Activated Protein Kinase via Somatostatin Receptor 1 (SSTR1)

1999 ◽  
Vol 13 (1) ◽  
pp. 24-37 ◽  
Author(s):  
Tullio Florio ◽  
Hong Yao ◽  
Kendall D. Carey ◽  
Tara J. Dillon ◽  
Philip J. S. Stork
Keyword(s):  
Growth Factor ◽  
Protein Kinase ◽  
Map Kinase ◽  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Somatostatin Receptor ◽  
Fibroblast Growth ◽  
Map Kinase Cascade ◽  
Mitogen Activated Protein ◽  
Kinase Cascade

Abstract Hormones and growth factors regulate cell growth via the mitogen-activated protein (MAP) kinase cascade. Here we examine the actions of the hormone somatostatin on the MAP kinase cascade through one of its two major receptor subtypes, the somatostatin receptor 1 (SSTR1) stably expressed in CHO-K1 cells. Somatostatin antagonizes the proliferative effects of fibroblast growth factor in CHO-SSTR1 cells via the SSTR1 receptor. However, in these cells, somatostatin robustly activates MAP kinase (also called extracellular signal regulated kinase; ERK) and augments fibroblast growth factor-stimulated ERK activity. We show that the activation of ERK via SSTR1 is pertussis toxin sensitive and requires the small G protein Ras, phosphatidylinositol 3-kinase, the serine/threonine kinase Raf-1, and the protein tyrosine phosphatase SHP-2. The activation of ERK by SSTR1 increased the expression of the cyclin-dependent protein kinase inhibitor p21cip1/WAF1. Previous studies have suggested that somatostatin-stimulated protein tyrosine phosphatase activity mediates the growth effects of somatostatin. Our data suggest that SHP-2 stimulation by SSTR1 may mediate some of these effects through the activation of the MAP kinase cascade and the expression of p21cip1/WAF1.

scholarly journals Stimulation of C2C12 myoblast growth by basic fibroblast growth factor and insulin-like growth factor 1 can occur via mitogen-activated protein kinase-dependent and -independent pathways.

1996 ◽  
Vol 16 (11) ◽  
pp. 5964-5973 ◽  
Author(s):  
D J Milasincic ◽  
M R Calera ◽  
S R Farmer ◽  
P F Pilch
Keyword(s):  
Growth Factor ◽  
Map Kinase ◽  
Fibroblast Growth Factor ◽  
Basic Fibroblast Growth Factor ◽  
Kinase Inhibitor ◽  
Cellular Responses ◽  
Fibroblast Growth ◽  
Map Kinase Cascade ◽  
Mitogen Activated Protein ◽  
Kinase Cascade

It is now well-recognized that the mitogen-activated protein (MAP) kinase cascade facilitates signaling from an activated tyrosine kinase receptor to the nucleus. In fact, an increasing number of extracellular effectors have been reported to activate the MAP kinase cascade, with a significant number of cellular responses attributed to this activation. We set out to explore how two extracellular effectors, basic fibroblast growth factor (bFGF) and insulin-like growth factor 1 (IGF-1), which have both been reported to activate MAP kinase, generate quite distinct cellular responses in C2C12 myoblasts. We demonstrate here that bFGF, which is both a potent mitogen and inhibitor of myogenic differentiation, is a strong MAP kinase agonist. By contrast, IGF-1, which is equally mitogenic for C2C12 cells but ultimately enhances the differentiated phenotype, is a weak activator of the MAP kinase cascade. We further demonstrate that IGF-1 is a potent activator of both insulin receptor substrate IRS-1 tyrosyl phosphorylation and association of IRS-1 with activated phosphatidylinositol 3-kinase (PI 3-kinase). Finally, use of the specific MAP kinase kinase inhibitor, PD098059, and wortmannin, a PI 3-kinase inhibitor, suggests the existence of an IGF-1-induced, MAP kinase-independent signaling event which contributes to the mitogenic response of this factor, whereas bFGF-induced mitogenesis appears to strongly correlate with activation of the MAP kinase cascade.

scholarly journals p42/mitogen-activated protein kinase as a converging target for different growth factor signaling pathways: use of pertussis toxin as a discrimination factor.

1991 ◽  
Vol 2 (8) ◽  
pp. 675-684 ◽  
Author(s):  
G L'Allemain ◽  
J Pouyssegur ◽  
M J Weber
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Protein Kinase ◽  
Map Kinase ◽  
Signaling Pathways ◽  
Fibroblast Growth Factor ◽  
Tyrosine Phosphorylation ◽  
Pertussis Toxin ◽  
Fibroblast Growth ◽  
Mitogen Activated Protein

Mitogen-activated protein (MAP) kinase is a 42-kDa serine/threonine-specific protein kinase that requires phosphorylation on both tyrosine and threonine residues for activity. This enzyme is rapidly and transiently activated in quiescent cells after addition of various agonists, including insulin, epidermal growth factor, platelet-derived growth factor, and phorbol esters. We show here that addition of the growth factors thrombin or basic fibroblast growth factor to CCL39 fibroblasts rapidly induces tyrosine phosphorylation of the p42 MAP kinase protein and concomitantly stimulates MAP kinase enzymatic activity. To elucidate the signaling pathways utilized in this activation, we took advantage of the sensitivity of CCL39 cells to the toxin of bordetella pertussis, which ADP-ribosylates two Gi proteins in this cell system. We show that pretreatment of cells with the toxin inhibited thrombin stimulation of MAP kinase by greater than 75% but had no detectable effect on the stimulation induced by basic fibroblast growth factor. We also demonstrate that these two growth factors that synergize for mitogenicity are able to cooperate in activation of MAP kinase and that this synergism is partially sensitive to pertussis toxin. Finally, we describe a 44-kDa protein, the tyrosine phosphorylation of which appears to be coregulated with p42 MAP kinase. We conclude that p42 MAP kinase (and the pp44 protein) are at or are downstream from a point of convergence of two different receptor-induced signaling pathways and might well play a key role in integrating those signals.

scholarly journals Fibroblast growth factor receptor signaling is essential for lens fiber cell differentiation

2008 ◽  
Vol 318 (2) ◽  
pp. 276-288 ◽  
Author(s):  
Haotian Zhao ◽  
Tianyu Yang ◽  
Bhavani P. Madakashira ◽  
Cornelius A. Thiels ◽  
Chad A. Bechtle ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Fibroblast Growth Factor Receptor ◽  
Growth Factor Receptor ◽  
Fiber Cell ◽  
Fibroblast Growth ◽  
Lens Fiber ◽  
Lens Fiber Cell ◽  
Growth Factor Receptor Signaling

scholarly journals The Docking Protein Gab1 Is an Essential Component of an Indirect Mechanism for Fibroblast Growth Factor Stimulation of the Phosphatidylinositol 3-Kinase/Akt Antiapoptotic Pathway

2004 ◽  
Vol 24 (13) ◽  
pp. 5657-5666 ◽  
Author(s):  
Betty Lamothe ◽  
Masashi Yamada ◽  
Ute Schaeper ◽  
Walter Birchmeier ◽  
Irit Lax ◽  
...  
Keyword(s):  
Growth Factor ◽  
Protein Kinase ◽  
Fibroblast Growth Factor ◽  
Critical Role ◽  
Mitogen Activated Protein Kinase ◽  
Fibroblast Growth ◽  
Indirect Mechanism ◽  
Docking Protein ◽  
Stimulation Of

ABSTRACT The docking protein Gab1 has been implicated as a mediator of multiple signaling pathways that are activated by a variety of receptor tyrosine kinases and cytokines. We have previously proposed that fibroblast growth factor 1 (FGF1) stimulation of tyrosine phosphorylation of Gab1 and recruitment of phosphatidylinositol (PI) 3-kinase are mediated by an indirect mechanism in which the docking protein fibroblast receptor substrate 2α (FRS2α) plays a critical role. In this report, we explore the role of Gab1 in FGF1 signaling by using mouse embryo fibroblasts (MEFs) derived from Gab1−/− or FRS2α−/− mice. We demonstrate that Gab1 is essential for FGF1 stimulation of both PI 3-kinase and the antiapoptotic protein kinase Akt, while FGF1-induced mitogen-activated protein kinase (MAPK) stimulation is not affected by Gab1 deficiency. To test the indirect mechanism for FGF1 stimulation of PI 3-kinase and Akt, we use a chimeric docking protein composed of the membrane targeting signal and the phosphotyrosine-binding domain of FRS2α fused to the C-terminal portion of Gab1, the region including the binding sites for the complement of signaling proteins that are recruited by Gab1. We demonstrate that expression of the chimeric docking protein in Gab1−/− MEFs rescues PI 3-kinase and the Akt responses, while expression of the chimeric docking protein in FRS2α−/− MEFs rescues stimulation of both Akt and MAPK. These experiments underscore the essential role of Gab1 in FGF1 stimulation of the PI 3-kinase/Akt signaling pathway and provide further support for the indirect mechanism for FGF1 stimulation of PI 3-kinase involving regulated assembly of a multiprotein complex.

A tyrosine-phosphorylated carboxy-terminal peptide of the fibroblast growth factor receptor (Flg) is a binding site for the SH2 domain of phospholipase C-gamma 1

1991 ◽  
Vol 11 (10) ◽  
pp. 5068-5078
Author(s):  
M Mohammadi ◽  
A M Honegger ◽  
D Rotin ◽  
R Fischer ◽  
F Bellot ◽  
...  
Keyword(s):  
Amino Acid ◽  
Growth Factor ◽  
Binding Site ◽  
Fibroblast Growth Factor ◽  
Tryptic Peptide ◽  
Fibroblast Growth Factor Receptor ◽  
Growth Factor Receptor ◽  
Sh2 Domain ◽  
Fibroblast Growth ◽  
Wild Type

Phospholipase C-gamma (PLC-gamma) is a substrate of the fibroblast growth factor receptor (FGFR; encoded by the flg gene) and other receptors with tyrosine kinase activity. It has been demonstrated that the src homology region 2 (SH2 domain) of PLC-gamma and of other signalling molecules such as GTPase-activating protein and phosphatidylinositol 3-kinase-associated p85 direct their binding toward tyrosine-autophosphorylated regions of the epidermal growth factor or platelet-derived growth factor receptor. In this report, we describe the identification of Tyr-766 as an autophosphorylation site of flg-encoded FGFR by direct sequencing of a tyrosine-phosphorylated tryptic peptide isolated from the cytoplasmic domain of FGFR expressed in Escherichia coli. The same phosphopeptide was found in wild-type FGFR phosphorylated either in vitro or in living cells. Like other growth factor receptors, tyrosine-phosphorylated wild-type FGFR or its cytoplasmic domain becomes associated with intact PLC-gamma or with a fusion protein containing the SH2 domain of PLC-gamma. To delineate the site of association, we have examined the capacity of a 28-amino-acid tryptic peptide containing phosphorylated Tyr-766 to bind to various constructs containing SH2 and other domains of PLC-gamma. It is demonstrated that the tyrosine-phosphorylated peptide binds specifically to the SH2 domain but not to the SH3 domain or other regions of PLC-gamma. Hence, Tyr-766 and its flanking sequences represent a major binding site in FGFR for PLC-gamma. Alignment of the amino acid sequences surrounding Tyr-766 with corresponding regions of other FGFRs revealed conserved tyrosine residues in all known members of the FGFR family. We propose that homologous tyrosine-phosphorylated regions in other FGFRs also function as binding sites for PLC-gamma and therefore are involved in coupling to phosphatidylinositol breakdown.

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