Steroid-induced oocyte maturation in Indian shad Tenualosa ilisha (Hamilton, 1822) is dependent on phosphatidylinositol 3 kinase but not MAP kinase activation

2014 ◽  
Vol 390 (1-2) ◽  
pp. 26-33 ◽  
Author(s):  
Kousik Pramanick ◽  
Sourav Kundu ◽  
Sudipta Paul ◽  
Buddhadev Mallick ◽  
Sujata Roy Moulik ◽  
...  
Keyword(s):  
Map Kinase ◽  
Oocyte Maturation ◽  
Phosphatidylinositol 3 Kinase ◽  
Kinase Activation ◽  
Tenualosa Ilisha ◽  
Phosphatidylinositol 3

scholarly journals Phosphatidylinositol 3-kinase activity is important for progesterone-induced Xenopus oocyte maturation.

1993 ◽  
Vol 13 (11) ◽  
pp. 6661-6666 ◽  
Author(s):  
A J Muslin ◽  
A Klippel ◽  
L T Williams
Keyword(s):  
Oocyte Maturation ◽  
Kinase Activity ◽  
Sh2 Domain ◽  
Pi3 Kinase ◽  
Meiotic Maturation ◽  
Xenopus Laevis Oocytes ◽  
Phosphatidylinositol 3 Kinase ◽  
Kinase Activation ◽  
Phosphatidylinositol 3

In somatic cells, phosphatidylinositol 3-kinase (PI3 kinase) is a critical intermediary in growth factor-induced mitogenesis. We have examined the role of this enzyme in meiotic maturation of Xenopus laevis oocytes. PI3 kinase activity was present in immunoprecipitates of the p85 subunit of PI3 kinase from immature oocytes and markedly increased following progesterone stimulation. Injection of bacterially expressed protein corresponding to the C-terminal SH2 domain of p85 (SH2-C) inhibited progesterone-induced PI3 kinase activation and meiotic maturation. Injection of protein corresponding to the N-terminal SH2 domain or the SH3 domain of p85 did not inhibit PI3 kinase activation or maturation. SH2-C did not inhibit oocyte maturation induced by c-mos RNA injection. In addition, radiolabelled SH2-C was used to probe oocyte lysates, revealing that a novel 200-kDa protein bound to SH2-C. This protein may be an important mediator of progesterone-induced lipid metabolism in oocytes.

scholarly journals Interleukin-2 triggers a novel phosphatidylinositol 3-kinase-dependent MEK activation pathway.

1995 ◽  
Vol 15 (6) ◽  
pp. 3049-3057 ◽  
Author(s):  
L M Karnitz ◽  
L A Burns ◽  
S L Sutor ◽  
J Blenis ◽  
R T Abraham
Keyword(s):  
Map Kinase ◽  
Interleukin 2 ◽  
Phosphatidylinositol 3 Kinase ◽  
Lipid Kinase ◽  
Kinase Activation ◽  
Activation Pathway ◽  
Drug Concentrations ◽  
Phase Entry ◽  
Phosphatidylinositol 3

Phosphatidylinositol 3-kinase (PI3-K) has been implicated as a signal-transducing component in interleukin-2 (IL-2)-induced mitogenesis. However, the function of this lipid kinase in regulating IL-2-triggered downstream events has remained obscure. Using the potent and specific PI3-K inhibitor, wortmannin, we assessed the role of PI3-K in IL-2-mediated signaling and proliferation in the murine T-cell line CTLL-2. Addition of the drug to exponentially growing cells resulted in an accumulation of cells in the G0/G1 phase of the cell cycle. Furthermore, wortmannin also partially suppressed IL-2-induced S-phase entry in G1-synchronized cells. Analysis of IL-2-triggered signaling pathways revealed that wortmannin pretreatment resulted in complete inhibition of IL-2-provoked p70 S6 kinase activation and also attenuated IL-2-induced MAP kinase activation at drug concentrations identical to those required for inhibition of PI3-K catalytic activity. Wortmannin also diminished the IL-2-triggered activation of the MAP kinase activator, MEK, but did not inhibit activation of Raf, the canonical upstream activator of MEK. These results suggest that a novel wortmannin-sensitive activation pathway regulates MEK and MAP kinase in IL-2-stimulated T lymphocytes.

scholarly journals Somatostatin Inhibits Akt Phosphorylation and Cell Cycle Entry, But Not p42/p44 Mitogen-Activated Protein (MAP) Kinase Activation in Normal and Tumoral Pancreatic Acinar Cells**This research was supported by Grant 970384 (to N.R.) from the Natural Sciences and Engineering Research Council of Canada.

Endocrinology ◽  
2001 ◽  
Vol 142 (1) ◽  
pp. 121-128 ◽  
Author(s):  
Stéphanie Charland ◽  
Marie-Josée Boucher ◽  
Mathieu Houde ◽  
Nathalie Rivard
Keyword(s):  
Cell Cycle ◽  
Map Kinase ◽  
Inhibitory Action ◽  
Map Kinases ◽  
Cyclin E ◽  
Pancreatic Acinar Cells ◽  
Phosphatidylinositol 3 Kinase ◽  
Kinase Activation ◽  
Rat Pancreas ◽  
Phosphatidylinositol 3

Abstract Somatostatin, or its structural analog SMS 201–995 (SMS), is recognized to exert a growth-inhibitory action in rat pancreas, but the cellular mechanisms are not completely understood. This study was undertaken to evaluate the effect of SMS on p42/p44 MAP kinases and phosphatidylinositol 3-kinase activation and to analyze expression of some cell cycle regulatory proteins in relation to pancreatic acinar cell proliferation in vivo (rat pancreas), as well as in the well-established tumoral cell line AR4–2J. We herein report that: 1) SMS inhibits caerulein-induced pancreatic weight and DNA content and abolishes epidermal growth factor (EGF)-stimulated AR4–2J proliferation; 2) SMS only moderately reduces the stimulatory effect of caerulein on p42/p44 MAP kinase activities in pancreas and has no effect on EGF-stimulated MAP kinase activities in AR4–2J cells; 3) SMS repressed caerulein-induced Akt activity in normal pancreas; 4) SMS has a strong inhibitory action on cyclin E expression induced by caerulein in pancreas and EGF in AR4–2J cells and as expected, the resulting cyclin E-associated cyclin-dependent kinase (cdk)2 activity, as well as pRb phosphorylation, are blunted by SMS treatment in both models; and 5) SMS suppresses mitogen-induced p27Kip1 down-regulation, as well as marginally induces p21Cip expression. Thus, our data suggest that somatostatin-induced growth arrest is mediated by inhibition of phosphatidylinositol 3-kinase pathway and by enhanced expression of p21Cip and p27Kip1, leading to repression of pRb phosphorylation and cyclin E-cdk2 complex activity.

Phosphatidylinositol 3-kinase activity is important for progesterone-induced Xenopus oocyte maturation

1993 ◽  
Vol 13 (11) ◽  
pp. 6661-6666
Author(s):  
A J Muslin ◽  
A Klippel ◽  
L T Williams
Keyword(s):  
Oocyte Maturation ◽  
Kinase Activity ◽  
Sh2 Domain ◽  
Pi3 Kinase ◽  
Meiotic Maturation ◽  
Xenopus Laevis Oocytes ◽  
Phosphatidylinositol 3 Kinase ◽  
Kinase Activation ◽  
Phosphatidylinositol 3

In somatic cells, phosphatidylinositol 3-kinase (PI3 kinase) is a critical intermediary in growth factor-induced mitogenesis. We have examined the role of this enzyme in meiotic maturation of Xenopus laevis oocytes. PI3 kinase activity was present in immunoprecipitates of the p85 subunit of PI3 kinase from immature oocytes and markedly increased following progesterone stimulation. Injection of bacterially expressed protein corresponding to the C-terminal SH2 domain of p85 (SH2-C) inhibited progesterone-induced PI3 kinase activation and meiotic maturation. Injection of protein corresponding to the N-terminal SH2 domain or the SH3 domain of p85 did not inhibit PI3 kinase activation or maturation. SH2-C did not inhibit oocyte maturation induced by c-mos RNA injection. In addition, radiolabelled SH2-C was used to probe oocyte lysates, revealing that a novel 200-kDa protein bound to SH2-C. This protein may be an important mediator of progesterone-induced lipid metabolism in oocytes.

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