Mitogen-activated protein kinase in human eggs

Zygote ◽  
1999 ◽  
Vol 7 (2) ◽  
pp. 181-185 ◽  
Author(s):  
Qing-Yuan Sun ◽  
Zeev Blumenfeld ◽  
Sara Rubinstein ◽  
Shlomit Goldman ◽  
Yael Gonen ◽  
...  
Keyword(s):  
Map Kinase ◽  
Mammalian Species ◽  
Germinal Vesicle ◽  
Mitogen Activated Protein Kinase ◽  
Early Embryos ◽  
Protein Map ◽  
Mitogen Activated Protein ◽  
Kinase Phosphorylation ◽  
Cycle Regulation ◽  
Kinase Expression

Mitogen-activated protein (MAP) kinase in human eggs has been investigated by using immunoblotting with both anti-Active MAPK and anti-ERK2 antibodies. The results showed that the main form of MAP kinase was p42ERK2. It was in a dephosphorylated form in oocytes at the germinal vesicle stage, but fully phosphorylated in unfertilised mature eggs. MAP kinase phosphorylation was significantly decreased when pronuclei were formed after intracytoplasmic sperm injection. Neither MAP kinase expression nor activity was detected in morphologically degenerated eggs. Although MAP kinase still existed in early embryos arrested at the 8-cell or morula stages, little, if any, activity could be detected. These data suggest that MAP kinase may play an important role in the cell cycle regulation of human eggs, as in other mammalian species.

cAMP inhibits mitogen-activated protein (MAP) kinase activation and resumption of meiosis, but exerts no effects after spontaneous germinal vesicle breakdown (GVBD) in mouse oocytes

1999 ◽  
Vol 11 (2) ◽  
pp. 81 ◽  
Author(s):  
Q. Y. Sun ◽  
Q. Lu ◽  
H. Breitbart ◽  
D. Y. Chen
Keyword(s):  
Map Kinase ◽  
Map Kinases ◽  
Specific Inhibitor ◽  
Germinal Vesicle ◽  
Germinal Vesicle Breakdown ◽  
Kinase Activation ◽  
Protein Map ◽  
Mitogen Activated Protein ◽  
Kinase Phosphorylation ◽  
Pkc Activation

Various signaling molecules have been implicated in the oocyte G2/MII transition, including protein kinase C (PKC), cAMP and mitogen-activated protein (MAP) kinases. However, the cross-talk among these signaling pathways has not been elucidated. The present study demonstrates that both germinal vesicle break down (GVBD) and MAP kinase phosphorylation (activation) are inhibited when intraoocyte cAMP is increased by treating the GV-intact oocytes with dibutyryl cyclic AMP (dbcAMP), forskolin, or isobutylmethylxanthine (IBMX). Okadaic acid, a specific inhibitor of protein phosphatase-1 and -2A, completely overcame this effect. Calphostin C, a specific inhibitor of PKC, accelerated both GVBD and MAP kinase phosphorylation, and this effect was attenuated by increased intraoocyte cAMP, whereas PKC activation inhibited these events. Once GVBD occurred, the progression of oocyte maturation and MAP kinase phosphorylation were independent of cAMP. These results indicate that an increase in intraoocyte cAMP, in synergy with PKC activation, initiates a cascade of events resulting in inhibition of MAP kinase phosphorylation and GVBD in the mouse oocyte.

Antioxidants stimulate meiosis resumption, but inhibit mitogen-activated protein kinase phosphorylation and further cell cycle progression in porcine oocytes

2000 ◽  
Vol 12 (8) ◽  
pp. 383 ◽  
Author(s):  
Q. Y. Sun ◽  
L. Lai ◽  
R. S. Prather ◽  
H. Schatten
Keyword(s):  
Map Kinase ◽  
Germinal Vesicle ◽  
Fluorescein Isothiocyanate ◽  
Nordihydroguaiaretic Acid ◽  
Mitogen Activated Protein Kinase ◽  
Dependent Manner ◽  
Germinal Vesicle Breakdown ◽  
Mitogen Activated Protein ◽  
Kinase Phosphorylation ◽  
Dose Dependent

In the present study the effects of two cell-permeant antioxidants, 2(3)-tert-butyl-4-hydroxyanisole (BHA) and nordihydroguaiaretic acid (NDGA), on porcine oocyte meiosis resumption, chromatin behaviour and spindle assembly were investigated. The antioxidants BHA and NDGA stimulated meiosis resumption in a dose-dependent manner in both cumulus-enclosed and denuded porcine oocytes. Afterin vitro culture for 8 h, few oocytes underwent germinal vesicle breakdown (GVBD) in control groups, whereas GVBD occurred in high percentages of oocytes treated with BHA or NDGA at concentrations that inhibit GVBD in rodent oocytes, although mitogen-activated protein (MAP) kinase was not phosphorylated as revealed by Western immunoblots. Orcein staining and fluorescein isothiocyanate-anti-· -tubulin labelling showed that chromosome and spindle formation, respectively, and further meiosis progression were inhibited 20 and 25 h after culture. Instead, chromatin was highly condensed or existed in scattered condensed clusters. Correspondingly, MAP kinase phosphorylation was inhibited by both BHA and NDGA in a dose-dependent manner. The inhibitory effects of BHA on meiosis completion and MAP kinase phosphorylation was reversible. These results suggest that, unlike in rodent oocytes, antioxidants stimulate GVBD in the absence of MAP kinase activation, but inhibit MAP kinase phosphorylation, meiotic apparatus formation and thus the further progression of the meiosis of porcine oocytes.

Functional Role of p38 Mitogen Activated Protein Kinase in Platelet Activation induced by a Thromboxane A2 Analogue and by 8-iso-prostaglandin F2 α

2002 ◽  
Vol 87 (05) ◽  
pp. 888-898 ◽  
Author(s):  
Stefania Gaino ◽  
Valeria Zuliani ◽  
Rosa Tommasoli ◽  
Donatella Benati ◽  
Riccardo Ortolani ◽  
...  
Keyword(s):  
Map Kinase ◽  
Platelet Activation ◽  
Tyrosine Kinases ◽  
Actin Polymerization ◽  
Shape Change ◽  
Specific Inhibitor ◽  
P38 Map Kinase ◽  
Mitogen Activated Protein Kinase ◽  
Mitogen Activated Protein ◽  
Kinase Phosphorylation

SummaryWe investigated similarities in the signaling pathways elicited by the F2 isoprostane 8-iso-PGF2α and by low doses of U46619 to induce platelet activation. Both 0.01-0.1 µmol/L U46619 and 0.01-1 µmol/L 8-isoPGF2α triggered shape change and filopodia extension, as well as adhesion to immobilized fibrinogen of washed platelets. At these doses the two platelet agonists failed to trigger secretion and aggregation, which were however induced by higher doses of U46619 (0.1-1 µmol/L). SB203580 (1-10 µmol/L), a specific inhibitor of the p38 mitogen activated protein (MAP) kinase blunted platelet shape change and adhesion induced by 0.05-1 µmol/L 8-iso-PGF2α and by 0.01 µmol/L U46619. These platelet responses were also inhibited by 20 µmol/L cytochalasin D, an inhibitor of actin polymerization, and 50 µmol/L piceatannol, an inhibitor of the Syk tyrosine kinases. Both 8-iso-PGF2α and U46619-induced p38 MAP kinase phosphorylation in suspended platelets and this was inhibited by piceatannol, indicating that Syk activation occurs upstream p38 MAP kinase phosphorylation. These findings suggest that the signaling pathway triggered by both 8-iso-PGF2α and low concentrations of U46619 to induce platelet adhesion and shape change implicates Syk, the p38 MAP kinase, and actin polymerization.

scholarly journals Two Adjacent Docking Sites in the Yeast Hog1 Mitogen-Activated Protein (MAP) Kinase Differentially Interact with the Pbs2 MAP Kinase Kinase and the Ptp2 Protein Tyrosine Phosphatase

2008 ◽  
Vol 28 (7) ◽  
pp. 2481-2494 ◽  
Author(s):  
Yulia Murakami ◽  
Kazuo Tatebayashi ◽  
Haruo Saito
Keyword(s):  
Map Kinase ◽  
Binding Sites ◽  
Tyrosine Phosphatase ◽  
Specific Interaction ◽  
Binding Domain ◽  
Mitogen Activated Protein Kinase ◽  
Protein Map ◽  
Mitogen Activated Protein ◽  
Initial Interaction ◽  
Docking Sites

ABSTRACT Functional interactions between a mitogen-activated protein kinase (MAPK) and its regulators require specific docking interactions. Here, we investigated the mechanism by which the yeast osmoregulatory Hog1 MAPK specifically interacts with its activator, the MAPK kinase Pbs2, and its major inactivator, the protein phosphatase Ptp2. We found, in the N-terminal noncatalytic region of Pbs2, a specific Hog1-binding domain, termed HBD-1. We also defined two adjacent Pbs2-binding sites in Hog1, namely, the common docking (CD) domain and Pbs2-binding domain 2 (PBD-2). The PBD-2 docking site appears to be sterically blocked in the intact Hog1 molecule, but its affinity to Pbs2 is apparent in shorter fragments of Hog1. Both the CD and the PBD-2 docking sites are required for the optimal activation of Hog1 by Pbs2, and in the absence of both sites, Hog1 cannot be activated by Pbs2. These data suggest that the initial interaction of Pbs2 with the CD site might induce a conformational change in Hog1 so that the PBD-2 site becomes accessible. The CD and PBD-2 docking sites are also involved in the specific interaction between Hog1 and Ptp2 and govern the dynamic dephosphorylation of activated Hog1. Thus, the CD and the PBD-2 docking sites play critical roles in both the activation and inactivation of Hog1.

scholarly journals Inhibition by adenylyl cyclase-cAMP system of ET-1-induced HSP27 in osteoblasts

2001 ◽  
Vol 281 (6) ◽  
pp. E1260-E1266 ◽  
Author(s):  
Daijiro Hatakeyama ◽  
Osamu Kozawa ◽  
Masayuki Niwa ◽  
Hiroyuki Matsuno ◽  
Kanefusa Kato ◽  
...  
Keyword(s):  
Map Kinase ◽  
Adenylyl Cyclase ◽  
Mrna Level ◽  
P38 Map Kinase ◽  
Hsp 27 ◽  
Kinase C ◽  
Protein Map ◽  
Mitogen Activated Protein ◽  
Camp System ◽  
Kinase Phosphorylation

We have previously reported that endothelin-1 (ET-1) stimulates heat shock protein (HSP) 27 induction in osteoblast-like MC3T3-E1 cells and that p38 mitogen-activated protein (MAP) kinase acts at a point downstream from protein kinase C (PKC) in HSP27 induction. In the present study, we investigated the effect of the adenylyl cyclase-cAMP system on ET-1-stimulated induction of HSP27 in MC3T3-E1 cells. Dibutyryl-cAMP (DBcAMP) dose dependently inhibited the HSP27 accumulation stimulated by ET-1. Forskolin and cholera toxin significantly suppressed the ET-1-stimulated accumulation of HSP27. However, dideoxyforskolin, a forskolin derivative that does not activate cAMP, failed to suppress the ET-1-induced HSP27 accumulation. Forskolin reduced the p38 MAP kinase phosphorylation induced by ET-1 or 12- O-tetradecanoylphorbol-13-acetate (TPA). PGE1, an extracellular agonist that activates cAMP production, reduced the ET-1-induced HSP27 accumulation. In addition, the phosphorylation of p38 MAP kinase induced by ET-1 or TPA was suppressed by PGE1. Forskolin, DBcAMP, and PGE1suppressed the ET-1-stimulated increase in the mRNA level for HSP27. These results indicate that the adenylyl cyclase-cAMP system has an inhibitory role in ET-1-stimulated HSP27 induction in osteoblasts and that the effect is exerted at the point between PKC and p38 MAP kinase in osteoblasts.

Inhibition of p42 and p44 MAP kinase does not alter smooth muscle contraction in swine carotid artery

1998 ◽  
Vol 275 (1) ◽  
pp. H131-H138 ◽  
Author(s):  
Isabelle Gorenne ◽  
Xiaoling Su ◽  
Robert S. Moreland
Keyword(s):  
Smooth Muscle ◽  
Muscle Contraction ◽  
Map Kinase ◽  
Map Kinases ◽  
Kinase Activity ◽  
Smooth Muscle Contraction ◽  
Protein Map ◽  
Mitogen Activated Protein ◽  
Kinase Phosphorylation

Caldesmon inhibits myosin ATPase activity; phosphorylation of caldesmon reverses the inhibition. The caldesmon kinase is believed to be mitogen-activated protein (MAP) kinase. MAP kinases are activated during vascular stimulation, but a cause-and-effect relationship between kinase activity and contraction has not been established. We examined the role of MAP kinase in contraction using PD-098059, an inhibitor of MAP kinase kinase (MEK). MAP kinase activity was assessed using an anti-active MAP kinase antibody and direct measurement of MAP kinase catalyzed phosphorylation of myelin basic protein, MBP-(95—98). MAP kinase phosphorylation, stimulated by histamine (50 μM) or phorbol 12,13-dibutyrate (PDBu, 0.1 μM), was inhibited by PD-098059 (100 μM). PD-098059 did not alter the sensitivity or the maximal level of force in smooth muscle stimulated by histamine or PDBu, nor did PD-098059 affect contraction of β-escin-permeabilized tissue. Our data suggest that p44 and p42 MAP kinases are not involved in regulation of vascular smooth muscle contraction. These results do not, however, preclude a role for other isoforms of the MAP kinase family.

scholarly journals Identification of the mitogen-activated protein kinase phosphorylation sites on human Sos1 that regulate interaction with Grb2.

1996 ◽  
Vol 16 (10) ◽  
pp. 5674-5682 ◽  
Author(s):  
S Corbalan-Garcia ◽  
S S Yang ◽  
K R Degenhardt ◽  
D Bar-Sagi
Keyword(s):  
Growth Factor ◽  
Map Kinase ◽  
Tyrosine Kinases ◽  
Phosphorylation Site ◽  
Mitogen Activated Protein Kinase ◽  
Phosphorylation Sites ◽  
Nucleotide Exchange ◽  
Mitogen Activated Protein ◽  
Son Of Sevenless ◽  
Kinase Phosphorylation

The Son of sevenless proteins (Sos) are guanine nucleotide exchange factors involved in the activation of Ras by cytoplasmic and receptor tyrosine kinases. Growth factor stimulation rapidly induces the phosphorylation of Sos on multiple serine and threonine sites. Previous studies have demonstrated that growth factor-induced Sos phosphorylation occurs at the C-terminal region of the protein and is mediated, in part, by mitogen-activated protein (MAP) kinase. In this report, we describe the identification of five MAP kinase sites (S-1137, S-1167, S-1178, S-1193, and S-1197) on hSos1. We demonstrate that four of these sites, S-1132, S-1167, S-1178, and S-1193, become phosphorylated following growth factor stimulation. The MAP kinase phosphorylation sites are clustered within a region encompassing three proline-rich SH3-binding sites in the C-terminal domain of hSos1. Replacing the MAP kinase phosphorylation sites with alanine residues results in an increase in the binding affinity of Grb2 to hSos1. Interestingly, hSos2 contains only one MAP kinase phosphorylation site and, as demonstrated previously, has an increased affinity toward Grb2 compared with hSos1. These results suggest a role for MAP kinase in the regulation of Grb2-Sos interactions. Since the binding of Grb2 is important for Sos function, the phosphorylation-dependent modulation of Grb2-Sos association may provide a means of controlling Ras activation.

scholarly journals The Stress-activated Mitogen-activated Protein Kinase Signaling Cascade Promotes Exit from Mitosis

2006 ◽  
Vol 17 (7) ◽  
pp. 3136-3146 ◽  
Author(s):  
Vladimír Reiser ◽  
Katharine E. D’Aquino ◽  
Ly-Sha Ee ◽  
Angelika Amon
Keyword(s):  
Map Kinase ◽  
Mitogen Activated Protein Kinase ◽  
Hog Pathway ◽  
Hypertonic Stress ◽  
Map Kinase Cascade ◽  
Protein Map ◽  
Mitogen Activated Protein ◽  
Early Anaphase ◽  
Kinase Cascade ◽  
Protein Kinase Signaling

In budding yeast, a signaling network known as the mitotic exit network (MEN) triggers exit from mitosis. We find that hypertonic stress allows MEN mutants to exit from mitosis in a manner dependent on the high osmolarity glycerol (HOG) mitogen-activated protein (MAP) kinase cascade. The HOG pathway drives exit from mitosis in MEN mutants by promoting the activation of the MEN effector, the protein phosphatase Cdc14. Activation of Cdc14 depends on the Cdc14 early anaphase release network, a group of proteins that functions in parallel to the MEN to promote Cdc14 function. Notably, exit from mitosis is promoted by the signaling branch defined by the Sho1 osmosensing system, but not by the Sln1 osmosensor of the HOG pathway. Our results suggest that the stress MAP kinase pathway mobilizes programs to promote completion of the cell cycle and entry into G1 under unfavorable conditions.

α1-Adrenergic activation of myocardial Na-K-2Cl cotransport involving mitogen-activated protein kinase

1998 ◽  
Vol 275 (2) ◽  
pp. H641-H652 ◽  
Author(s):  
Geir Øystein Andersen ◽  
Mette Enger ◽  
G. Hege Thoresen ◽  
Tor Skomedal ◽  
Jan-Bjørn Osnes
Keyword(s):  
Protein Kinase ◽  
Map Kinase ◽  
Mitogen Activated Protein Kinase ◽  
Extracellular Signal ◽  
Rat Hearts ◽  
Protein Map ◽  
Mitogen Activated Protein ◽  
Β Blocker ◽  
Map Kinase Pathway ◽  
Erk Activity

The translocation mechanisms involved in the α1-adrenoceptor-stimulated efflux of the potassium analog86Rb+were studied in isolated rat hearts. Phenylephrine (in the presence of a β-blocker) increased the efflux of86Rb+and42K+, and the Na-K-2Cl (or K-Cl) cotransport inhibitor bumetanide reduced the response by 42 ± 11%. Furosemide inhibited the response with a lower potency than that of bumetanide. The bumetanide-insensitive efflux was largely sensitive to the K+ channel inhibitor 4-aminopyridine. Inhibitors of the Na+/H+exchanger or the Na+-K+pump had no effect on the increased86Rb+efflux. The activation of the Na-K-2Cl cotransporter was dependent on the extracellular signal-regulated kinase (ERK) subgroup of the mitogen-activated protein (MAP) kinase family. Phenylephrine stimulation increased ERK activity 3.4-fold. PD-98059, an inhibitor of the ERK cascade, reduced both the increased86Rb+efflux and ERK activity. Specific inhibitors of protein kinase C and Ca2+/calmodulin-dependent kinase II had no effect. In conclusion, α1-adrenoceptor stimulation increases86Rb+efflux from the rat heart via K+channels and a Na-K-2Cl cotransporter. Activation of the Na-K-2Cl cotransporter is apparently dependent on the MAP kinase pathway.

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