scholarly journals A Truncated Kringle Domain of Human Apolipoprotein(a) Inhibits the Activation of Extracellular Signal-regulated Kinase 1 and 2 through a Tyrosine Phosphatase-dependent Pathway

2004 ◽  
Vol 279 (21) ◽  
pp. 21808-21814 ◽  
Author(s):  
Jin-Hyung Ahn ◽  
Jang-Seong Kim ◽  
Hyun-Kyung Yu ◽  
Ho-Jeong Lee ◽  
Yeup Yoon
Keyword(s):  
Tyrosine Phosphatase ◽  
Kringle Domain ◽  
Extracellular Signal Regulated Kinase ◽  
Human Apolipoprotein ◽  
Apolipoprotein A ◽  
Extracellular Signal ◽  
Dependent Pathway

scholarly journals Soluble Fibrinogen Modulates Neutrophil Functionality Through the Activation of an Extracellular Signal-Regulated Kinase-Dependent Pathway

2002 ◽  
Vol 168 (7) ◽  
pp. 3527-3535 ◽  
Author(s):  
Carolina Rubel ◽  
Gabriela C. Fernández ◽  
Fernanda Alves Rosa ◽  
Sonia Gómez ◽  
Macarena Beigier Bompadre ◽  
...  
Keyword(s):  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Dependent Pathway

Mechanism of eosinophil induced signaling in cholinergic IMR-32 cells

2005 ◽  
Vol 288 (2) ◽  
pp. L326-L332 ◽  
Author(s):  
David R. Curran ◽  
Ross K. Morgan ◽  
Paul J. Kingham ◽  
Niamh Durcan ◽  
W. Graham McLean ◽  
...  
Keyword(s):  
Adhesion Molecules ◽  
Neurotransmitter Release ◽  
Interleukin 1 ◽  
Nerve Cells ◽  
Intercellular Adhesion Molecule ◽  
Intercellular Adhesion Molecule 1 ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Induced Apoptosis ◽  
Dependent Pathway

Eosinophils interact with nerve cells, leading to changes in neurotransmitter release, altered nerve growth, and protection from cytokine-induced apoptosis. In part, these interactions occur as a result of activation of neural nuclear factor (NF)-κB, which is activated by adhesion of eosinophils to neural intercellular adhesion molecule-1 (ICAM-1). The mechanism and consequence of signaling after eosinophil adhesion to nerve cells were investigated. Eosinophil membranes, which contain eosinophil adhesion molecules but not other eosinophil products, were coincubated with IMR-32 cholinergic nerve cells. The studies showed that there were two mechanisms of activation of NF-κB, one of which was dependent on reactive oxygen species, since it was inhibited with diphenyleneiodonium. This occurred at least 30 min after coculture of eosinophils and nerves. An earlier phase of NF-κB activation occurred within 2 min of eosinophil adhesion and was mediated by tyrosine kinase-dependent phosphorylation of interleukin-1 receptor-associated kinase-1 (IRAK-1). Coimmunoprecipitation experiments showed that both extracellular signal-regulated kinase 1/2 and IRAK-1 were recruited to ICAM-1 rapidly after coculture with eosinophil membranes. This was accompanied by an induction of ICAM-1, which was mediated by an IRAK-1-dependent pathway. These data indicate that adhesion of eosinophils to IMR-32 nerves via ICAM-1 leads to important signaling events, mediated via IRAK-1, and these in turn lead to expression of adhesion molecules.

scholarly journals The Tyrosine Phosphatase SHP-2 Is Required for Sustained Activation of Extracellular Signal-Regulated Kinase and Epithelial Morphogenesis Downstream from the Met Receptor Tyrosine Kinase

2000 ◽  
Vol 20 (22) ◽  
pp. 8513-8525 ◽  
Author(s):  
Christiane R. Maroun ◽  
Monica A. Naujokas ◽  
Marina Holgado-Madruga ◽  
Albert J. Wong ◽  
Morag Park
Keyword(s):  
Growth Factor ◽  
Tyrosine Phosphatase ◽  
Epithelial Morphogenesis ◽  
Met Receptor ◽  
Erk Activation ◽  
Extracellular Signal Regulated Kinase ◽  
Transient Activation ◽  
Extracellular Signal ◽  
Positive Modulator ◽  
Sustained Activation

ABSTRACT Epithelial morphogenesis is critical during development and wound healing, and alterations in this program contribute to neoplasia. Met, the hepatocyte growth factor (HGF) receptor, promotes a morphogenic program in epithelial cell lines in matrix cultures. Previous studies have identified Gab1, the major phosphorylated protein following Met activation, as important for the morphogenic response. Gab1 is a docking protein that couples the Met receptor with multiple signaling proteins, including phosphatidylinositol-3 kinase, phospholipase Cγ, the adapter protein Crk, and the tyrosine specific phosphatase SHP-2. HGF induces sustained phosphorylation of Gab1 and sustained activation of extracellular signal-regulated kinase (Erk) in epithelial Madin-Darby canine kidney cells. In contrast, epidermal growth factor fails to promote a morphogenic program and induces transient Gab1 phosphorylation and Erk activation. To elucidate the Gab1-dependent signals required for epithelial morphogenesis, we undertook a structure-function approach and demonstrate that association of Gab1 with the tyrosine phosphatase SHP-2 is required for sustained Erk activation and for epithelial morphogenesis downstream from the Met receptor. Epithelial cells expressing a Gab1 mutant protein unable to recruit SHP-2 elicit a transient activation of Erk in response to HGF. Moreover, SHP-2 catalytic activity is required, since the expression of a catalytically inactive SHP-2 mutant, C/S, abrogates sustained activation of Erk and epithelial morphogenesis by the Met receptor. These data identify SHP-2 as a positive modulator of Erk activity and epithelial morphogenesis downstream from the Met receptor.

scholarly journals A Novel Regulatory Mechanism of Map Kinases Activation and Nuclear Translocation Mediated by Pka and the Ptp-Sl Tyrosine Phosphatase

1999 ◽  
Vol 147 (6) ◽  
pp. 1129-1136 ◽  
Author(s):  
Carmen Blanco-Aparicio ◽  
Josema Torres ◽  
Rafael Pulido
Keyword(s):  
Map Kinases ◽  
Nuclear Translocation ◽  
Tyrosine Phosphatase ◽  
Phosphorylation Site ◽  
Extracellular Signal Regulated Kinase ◽  
Inactive Form ◽  
Extracellular Signal ◽  
Protein Map ◽  
Mitogen Activated Protein ◽  
Dependent Protein

Protein tyrosine phosphatase PTP-SL retains mitogen-activated protein (MAP) kinases in the cytoplasm in an inactive form by association through a kinase interaction motif (KIM) and tyrosine dephosphorylation. The related tyrosine phosphatases PTP-SL and STEP were phosphorylated by the cAMP-dependent protein kinase A (PKA). The PKA phosphorylation site on PTP-SL was identified as the Ser231 residue, located within the KIM. Upon phosphorylation of Ser231, PTP-SL binding and tyrosine dephosphorylation of the MAP kinases extracellular signal–regulated kinase (ERK)1/2 and p38α were impaired. Furthermore, treatment of COS-7 cells with PKA activators, or overexpression of the Cα catalytic subunit of PKA, inhibited the cytoplasmic retention of ERK2 and p38α by wild-type PTP-SL, but not by a PTP-SL S231A mutant. These findings support the existence of a novel mechanism by which PKA may regulate the activation and translocation to the nucleus of MAP kinases.

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