Schizosaccharomyces pombe Spk1 is a tyrosine-phosphorylated protein functionally related to Xenopus mitogen-activated protein kinase.

Mitogen-activated protein kinase (MAPK) and its direct activator, MAPK kinase (MAPKK), have been suggested to play a pivotal role in a variety of signal transduction pathways in higher eukaryotes. The fission yeast Schizosaccharomyces pombe carries a gene, named spk1, whose product is structurally related to vertebrate MAPK. Here we show that Spk1 is functionally related to Xenopus MAPK. (i) Xenopus MAPK partially complemented a defect in the spk1- mutant. An spk1- diploid strain could not sporulate, but one carrying Xenopus MAPK could. (ii) Both Spk1 and Xenopus MAPK interfered with sporulation if overexpressed in S. pombe cells. (iii) Spk1 underwent tyrosine phosphorylation as does Xenopus MAPK. Tyrosine phosphorylation of Spk1 appeared to be dependent upon mating signals because it occurred in homothallic cells but not in heterothallic cells. Furthermore, this phosphorylation was diminished in a byr1 disruptant strain, suggesting that spk1 lies downstream of byr1, which encodes a MAPKK homolog in S. pombe. Taken together, the MAPKK-MAPK cascade may be evolutionarily conserved in signaling pathways in yeasts and vertebrates.

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Activation of the Mitogen-activated Protein Kinase Pathway by fMet-Leu-Phe in the Absence of Lyn and Tyrosine Phosphorylation of SHC in Transfected Cells

Journal of Biological Chemistry ◽

10.1074/jbc.271.22.13244 ◽

1996 ◽

Vol 271 (22) ◽

pp. 13244-13249 ◽

Cited By ~ 19

Author(s):

Martine Torres ◽

Richard D. Ye

Keyword(s):

Protein Kinase ◽

Tyrosine Phosphorylation ◽

Mitogen Activated Protein Kinase ◽

Transfected Cells ◽

Mitogen Activated Protein ◽

Kinase Pathway

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Dissociation of mitogen-activated protein kinase activation from p125 focal adhesion kinase tyrosine phosphorylation in Swiss 3T3 cells stimulated by bombesin, lysophosphatidic acid, and platelet-derived growth factor.

Molecular Biology of the Cell ◽

10.1091/mbc.7.12.1865 ◽

1996 ◽

Vol 7 (12) ◽

pp. 1865-1875 ◽

Cited By ~ 54

Author(s):

T Seufferlein ◽

D J Withers ◽

D Mann ◽

E Rozengurt

Keyword(s):

Protein Kinase ◽

Tyrosine Phosphorylation ◽

Focal Adhesion ◽

Lysophosphatidic Acid ◽

Mitogen Activated Protein Kinase ◽

Platelet Derived Growth Factor ◽

3T3 Cells ◽

Kinase C ◽

Mitogen Activated Protein ◽

Swiss 3T3

The experiments presented here were designed to examine the contribution of p125 focal adhesion kinase (p125FAK) tyrosine phosphorylation to the activation of the mitogen-activated protein kinase cascade induced by bombesin, lysophosphatidic acid (LPA), and platelet-derived growth factor (PDGF) in Swiss 3T3 cells. We found that tyrosine phosphorylation of p125FAK in response to these growth factors is completely abolished in cells treated with cytochalasin D or in cells that were suspended in serum-free medium for 30 min. In marked contrast, the activation of p42mapk by these factors was independent of the integrity of the actin cytoskeleton and of the interaction of the cells with the extracellular matrix. The protein kinase C inhibitor GF 109203X and down-regulation of protein kinase C by prolonged pretreatment of cells with phorbol esters blocked bombesin-stimulated activation of p42mapk, p90rsk, and MAPK kinase-1 but did not prevent bombesin-induced tyrosine phosphorylation of p125FAK. Furthermore, LPA-induced p42mapk activation involved a pertussis toxin-sensitive guanylate nucleotide-binding protein, whereas tyrosine phosphorylation of p125FAK in response to LPA was not prevented by pretreatment with pertussis toxin. Finally, PDGF induced maximum p42mapk activation at concentrations (30 ng/ml) that failed to induce tyrosine phosphorylation of p125FAK. Thus, our results demonstrate that p42mapk activation in response to bombesin, LPA, and PDGF can be dissociated from p125FAK tyrosine phosphorylation in Swiss 3T3 cells.

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Identification of Cdc37 as a Novel Regulator of the Stress-Responsive Mitogen-Activated Protein Kinase

Molecular and Cellular Biology ◽

10.1128/mcb.23.15.5132-5142.2003 ◽

2003 ◽

Vol 23 (15) ◽

pp. 5132-5142 ◽

Cited By ~ 34

Author(s):

Hisashi Tatebe ◽

Kazuhiro Shiozaki

Keyword(s):

Protein Kinase ◽

Protein Kinases ◽

Inflammatory Responses ◽

Cellular Level ◽

Mitogen Activated Protein Kinase ◽

Cellular Survival ◽

Evolutionarily Conserved ◽

Mitogen Activated Protein ◽

Extracellular Stimuli ◽

The Stability

ABSTRACT Eukaryotic cells utilize multiple mitogen-activated protein kinases (MAPKs) to transmit various extracellular stimuli to the nucleus. A subfamily of MAPKs that mediates environmental stress stimuli is also called stress-activated protein kinase (SAPK), which has crucial roles in cellular survival under stress conditions as well as inflammatory responses. Here we report that Cdc37, an evolutionarily conserved kinase-specific chaperone, is a positive regulator of Spc1 SAPK in the fission yeast Schizosaccharomyces pombe. Through a genetic screen, we have identified cdc37 as a mutation that compromises signaling through Spc1 SAPK. The Cdc37 protein physically interacts with Spc1, and the cdc37 mutation affects both the cellular level of the Spc1 protein and stress-induced Spc1 phosphorylation by Wis1 MAPK kinase (MAPKK). Consistently, expression of the stress response genes regulated by the Spc1 pathway is compromised in cdc37 mutant cells. On the other hand, a mutation in Hsp90, which often cooperates with Cdc37 in chaperoning protein kinases, does not affect Spc1 SAPK. These results suggest that Spc1 SAPK is a novel client protein for the Cdc37 chaperone, and the Cdc37 function is important to maintain the stability of the Spc1 protein and to facilitate stress signaling from Wis1 MAPKK to Spc1 SAPK.

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Uniaxial Cyclic Stretch Induces Focal Adhesion Kinase (FAK) Tyrosine Phosphorylation Followed by Mitogen-Activated Protein Kinase (MAPK) Activation

Biochemical and Biophysical Research Communications ◽

10.1006/bbrc.2001.5775 ◽

2001 ◽

Vol 288 (2) ◽

pp. 356-361 ◽

Cited By ~ 82

Author(s):

Ju Guang Wang ◽

Motoi Miyazu ◽

Etsushi Matsushita ◽

Masahiro Sokabe ◽

Keiji Naruse

Keyword(s):

Protein Kinase ◽

Focal Adhesion Kinase ◽

Tyrosine Phosphorylation ◽

Focal Adhesion ◽

Cyclic Stretch ◽

Mitogen Activated Protein Kinase ◽

Mapk Activation ◽

Mitogen Activated Protein

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Growth hormone activates mitogen-activated protein kinase and S6 kinase and promotes intracellular tyrosine phosphorylation in 3T3-F442A preadipocytes

Biochemical Journal ◽

10.1042/bj2840649 ◽

1992 ◽

Vol 284 (3) ◽

pp. 649-652 ◽

Cited By ~ 49

Author(s):

N G Anderson

Keyword(s):

Growth Hormone ◽

Protein Kinase C ◽

Protein Kinase ◽

Tyrosine Phosphorylation ◽

Phorbol Esters ◽

Mitogen Activated Protein Kinase ◽

S6 Kinase ◽

Kinase C ◽

Transient Activation ◽

Mitogen Activated Protein

Physiological concentrations of growth hormone induced a rapid and transient activation of mitogen-activated protein kinase (MAP kinase) and S6 kinase in 3T3-F442A preadipocytes. These effects were abrogated by staurosporine and in cells chronically pretreated with phorbol esters, suggesting that protein kinase C is involved in the mechanism of activation. In addition, three cytosolic proteins exhibited a growth-hormone-dependent increase in tyrosine phosphorylation.

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The Phosphotyrosine Phosphatase SHP-2 Participates in a Multimeric Signaling Complex and Regulates T Cell Receptor (TCR) coupling to the Ras/Mitogen-activated Protein Kinase (MAPK) Pathway in Jurkat T Cells

Journal of Experimental Medicine ◽

10.1084/jem.187.9.1417 ◽

1998 ◽

Vol 187 (9) ◽

pp. 1417-1426 ◽

Cited By ~ 86

Author(s):

Julie A. Frearson ◽

Denis R. Alexander

Keyword(s):

T Cells ◽

Protein Kinase ◽

Tyrosine Phosphorylation ◽

T Cell Receptor ◽

Mapk Pathway ◽

Cell Receptor ◽

Mitogen Activated Protein Kinase ◽

Wild Type ◽

Jurkat T Cells ◽

Mitogen Activated Protein

Src homology 2 (SH2) domain–containing phosphotyrosine phosphatases (SHPs) are increasingly being shown to play critical roles in protein tyrosine kinase–mediated signaling pathways. The role of SHP-1 as a negative regulator of T cell receptor (TCR) signaling has been established. To further explore the function of the other member of this family, SHP-2, in TCR-mediated events, a catalytically inactive mutant SHP-2 was expressed under an inducible promoter in Jurkat T cells. Expression of the mutant phosphatase significantly inhibited TCR-induced activation of the extracellular-regulated kinase (ERK)-2 member of the mitogen-activated protein kinase (MAPK) family, but had no effect on TCR-ζ chain tyrosine phosphorylation or TCR-elicited Ca2+ transients. Inactive SHP-2 was targeted to membranes resulting in the selective increase in tyrosine phosphorylation of three membrane-associated candidate SHP-2 substrates of 110 kD, 55-60 kD, and 36 kD, respectively. Analysis of immunoprecipitates containing inactive SHP-2 also indicated that the 110-kD and 36-kD Grb-2–associated proteins were putative substrates for SHP-2. TCR-stimulation of Jurkat T cells expressing wild-type SHP-2 resulted in the formation of a multimeric cytosolic complex composed of SHP-2, Grb-2, phosphatidylinositol (PI) 3′-kinase, and p110. A significant proportion of this complex was shown to be membrane associated, presumably as a result of translocation from the cytosol. Catalytically inactive SHP-2, rather than the wild-type PTPase, was preferentially localized in complex with Grb-2 and the p85 subunit of PI 3′-kinase, suggesting that the dephosphorylating actions of SHP-2 may regulate the association of these signaling molecules to the p110 complex. Our results show that SHP-2 plays a critical role in linking the TCR to the Ras/MAPK pathway in Jurkat T cells, and also provide some insight into the molecular interactions of SHP-2 that form the basis of this signal transduction process.

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