299 LEPTIN ACCELERATES PRONUCLEAR FORMATION FOLLOWING INTRACYTOPLASMIC SPERM INJECTION OF PORCINE OOCYTES: POSSIBLE ROLE OF MITOGEN-ACTIVATED PROTEIN KINASE INACTIVATION

2007 ◽  
Vol 19 (1) ◽  
pp. 265
Author(s):  
Y. X. Jin ◽  
X. S. Cui ◽  
W. K. Chang ◽  
T. Kim ◽  
N. H. Kim
Keyword(s):  
Protein Kinase ◽  
Oocyte Maturation ◽  
Intracytoplasmic Sperm Injection ◽  
Treated Group ◽  
Mitogen Activated Protein Kinase ◽  
Parthenogenetic Activation ◽  
Mitogen Activated Protein ◽  
Cytoplasmic Maturation ◽  
Pronuclear Formation

Although evidence suggests that leptin modulates oocyte maturation in vitro, few studies have examined the direct effect of leptin on cytoplasmic maturation and pronuclear formation following fertilization of porcine oocytes.The aim of this studywas to determine microtubule and microfilament assembly following oocyte maturation, and to assess blastocyst formation, mitogen-activated protein kinase (MAPK) activity, and pronuclear formation following parthenogenetic stimuli or intracytoplasmic sperm injection (ICSI) of leptin-treated oocytes.A symmetrical shape of the meiotic spindle was considered to be the normal microtubule assembly, and a clear, thick microfilament area containing a second metaphase chromatin was considered to be morphologically normal. Significant differences were determined using Tukey's multiple range test with P < 0.05 being considered significant. Addition of 10 ng mL-1 of leptin to the in vitro maturation (IVM) medium significantly increased the percentage of zygotes that developed to the blastocyst stage (26.1 � 2.1%; P < 0.05) compared with that of the control (0 ng mL-1: 16.3 � 2.8%) or 1 ng mL-1 (18.6 � 2.6%) leptin treatment groups following parthenogenetic activation. After IVM for 44 h, the percentage of oocytes with normal microtubules was higher in the leptin (10 ng mL-1) group than in the control group (89.1 � 4.3% vs. 78.5 � 4.0%, respectively; P < 0.05). However, the percentage of normal microfilament assembly was similar in the leptin-treated and control groups (85.6 � 4.3% and 82.9 � 5.0%, respectively). In oocytes matured in vitro in the presence of 10 ng mL-1 of leptin and subsequently induced by parthenogenetic activation via chemical stimulation, there was a significant increase in the formation of 2 pronuclei (2PN: 52.1 � 5.2%; P < 0.05) at 6 h, compared with the control non-leptin-treated oocytes (40.7 � 4.0%). Similarly, addition of 10 ng mL-1 of leptin to the IVM medium also increased 2PN formation at the same time point following ICSI (leptin treatment: 47.9 � 4.0; control: 36.2 � 3.8%; P < 0.05). The addition of 10 ng mL-1 of leptin to the IVM medium decreased the level of phospho-ERK1/2 at 6 and 9 h and was lower in the leptin-treated group compared with the control non-leptin-treated group (P < 0.01). These results suggest that exogenous leptin enhances cytoplasmic maturation and pronuclear formation following fertilization, possibly via the MAPK pathway.

Treatment of allicin improves maturation of immature oocytes and subsequent developmental ability of preimplantation embryos

Zygote ◽  
2017 ◽  
Vol 25 (4) ◽  
pp. 480-488 ◽  
Author(s):  
Sang-Gi Jeong ◽  
Seung-Eun Lee ◽  
Yun-Gwi Park ◽  
Yeo-Jin Son ◽  
Min-Young Shin ◽  
...  
Keyword(s):  
Oocyte Maturation ◽  
Polar Body ◽  
Treated Group ◽  
Developmental Competence ◽  
Mitogen Activated Protein Kinase ◽  
Preimplantation Embryos ◽  
Maturation Medium ◽  
Mitogen Activated Protein ◽  
Porcine Oocyte

SummaryAllicin (AL) regulates the cellular redox, proliferation, viability, and cell cycle of different cells against extracellular-derived stress. This study investigated the effects of allicin treatment on porcine oocyte maturation and developmental competence. Porcine oocytes were cultured in medium supplemented with 0 (control), 0.01, 0.1, 1, 10 or 100 μM AL, respectively, during in vitro maturation (IVM). The rate of polar body emission was higher in the 0.1 AL-treated group (74.5% ± 2.3%) than in the control (68.0% ± 2.6%) (P < 0.1). After parthenogenetic activation, the rates of cleavage and blastocyst formation were significantly higher in the 0.1 AL-treated group than in the control (P < 0.05). The reactive oxygen species level at metaphase II did not significantly differ among all groups. In matured oocytes, the expression of both BAK and CASP3, and BIRC5 was significantly lower and higher, respectively, in the 0.1 AL-treated group than in the control. Similarly, the expression of BMP15 and CCNB1, and the activity of phospho-p44/42 mitogen-activated protein kinase (MAPK), significantly increased. These results indicate that supplementation of oocyte maturation medium with allicin during IVM improves the maturation of oocytes and the subsequent developmental competence of porcine oocytes.

scholarly journals Mechanistic Studies of the Mitotic Activation of Mos

2006 ◽  
Vol 26 (14) ◽  
pp. 5300-5309 ◽  
Author(s):  
Jianbo Yue ◽  
James E. Ferrell
Keyword(s):  
Protein Kinase ◽  
Oocyte Maturation ◽  
Tyrosine Kinases ◽  
Spindle Assembly Checkpoint ◽  
Phosphorylation Site ◽  
Kinase Domain ◽  
Mitogen Activated Protein Kinase ◽  
Egg Extracts ◽  
Mitogen Activated Protein

ABSTRACT The protein kinase Mos is responsible for the activation of MEK1 and p42 mitogen-activated protein kinase during Xenopus oocyte maturation and during mitosis in Xenopus egg extracts. Here we show that the activation of Mos depends upon the phosphorylation of Ser 3, a residue previously implicated in the regulation of Mos stability; the dephosphorylation of Ser 105, a previously unidentified phosphorylation site conserved in Mos proteins; and the regulated dissociation of Mos from CK2β. Mutation of Ser 3 to alanine and/or mutation of Ser 105 to glutamate produces a Mos protein that is defective for M-phase activation, as assessed by in vitro kinase assays, and defective for induction of oocyte maturation and maintenance of the spindle assembly checkpoint in extracts. Interestingly, Ser 105 is situated at the beginning of helix αC in the N-terminal lobe of the Mos kinase domain. Changes in the orientation of this helix have been previously implicated in the activation of Cdk2 and Src family tyrosine kinases. Our work suggests that Ser 105 dephosphorylation represents a novel mechanism for reorienting helix αC.

scholarly journals Cross-talk between IRAK-4 and the NADPH oxidase1

2007 ◽  
Vol 403 (3) ◽  
pp. 451-461 ◽  
Author(s):  
Sandrine Pacquelet ◽  
Jennifer L. Johnson ◽  
Beverly A. Ellis ◽  
Agnieszka A. Brzezinska ◽  
William S. Lane ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Nadph Oxidase ◽  
P38 Mapk ◽  
Interleukin 1 ◽  
Mitogen Activated Protein Kinase ◽  
Free System ◽  
Mitogen Activated Protein ◽  
A Cell ◽  
Tlr4 Activation

Exposure of neutrophils to LPS (lipopolysaccharide) triggers their oxidative response. However, the relationship between the signalling downstream of TLR4 (Toll-like receptor 4) after LPS stimulation and the activation of the oxidase remains elusive. Phosphorylation of the cytosolic factor p47phox is essential for activation of the NADPH oxidase. In the present study, we examined the hypothesis that IRAK-4 (interleukin-1 receptor-associated kinase-4), the main regulatory kinase downstream of TLR4 activation, regulates the NADPH oxidase through phosphorylation of p47phox. We show that p47phox is a substrate for IRAK-4. Unlike PKC (protein kinase C), IRAK-4 phosphorylates p47phox not only at serine residues, but also at threonine residues. Target residues were identified by tandem MS, revealing a novel threonine-rich regulatory domain. We also show that p47phox is phosphorylated in granulocytes in response to LPS stimulation. LPS-dependent phosphorylation of p47phox was enhanced by the inhibition of p38 MAPK (mitogen-activated protein kinase), confirming that the kinase operates upstream of p38 MAPK. IRAK-4-phosphorylated p47phox activated the NADPH oxidase in a cell-free system, and IRAK-4 overexpression increased NADPH oxidase activity in response to LPS. We have shown that endogenous IRAK-4 interacts with p47phox and they co-localize at the plasma membrane after LPS stimulation, using immunoprecipitation assays and immunofluorescence microscopy respectively. IRAK-4 was activated in neutrophils in response to LPS stimulation. We found that Thr133, Ser288 and Thr356, targets for IRAK-4 phosphorylation in vitro, are also phosphorylated in endogenous p47phox after LPS stimulation. We conclude that IRAK-4 phosphorylates p47phox and regulates NADPH oxidase activation after LPS stimulation.

Far1 and Fus3 link the mating pheromone signal transduction pathway to three G1-phase Cdc28 kinase complexes

1993 ◽  
Vol 13 (9) ◽  
pp. 5659-5669 ◽  
Author(s):  
M Tyers ◽  
B Futcher
Keyword(s):  
Signal Transduction ◽  
Protein Kinase ◽  
Signal Transduction Pathway ◽  
Mitogen Activated Protein Kinase ◽  
G1 Phase ◽  
Transduction Pathway ◽  
Yeast Saccharomyces Cerevisiae ◽  
Alpha Factor ◽  
Mitogen Activated Protein

In the yeast Saccharomyces cerevisiae, the Cdc28 protein kinase controls commitment to cell division at Start, but no biologically relevant G1-phase substrates have been identified. We have studied the kinase complexes formed between Cdc28 and each of the G1 cyclins Cln1, Cln2, and Cln3. Each complex has a specific array of coprecipitated in vitro substrates. We identify one of these as Far1, a protein required for pheromone-induced arrest at Start. Treatment with alpha-factor induces a preferential association and/or phosphorylation of Far1 by the Cln1, Cln2, and Cln3 kinase complexes. This induced interaction depends upon the Fus3 protein kinase, a mitogen-activated protein kinase homolog that functions near the bottom of the alpha-factor signal transduction pathway. Thus, we trace a path through which a mitogen-activated protein kinase regulates a Cdc2 kinase.

Sign in / Sign up

Export Citation Format

Share Document