IN VITRO METABOLISM OF THE PHOSPHATIDYLINOSITOL 3-KINASE INHIBITOR, WORTMANNIN, BY CARBONYL REDUCTASE

2004 ◽  
Vol 32 (5) ◽  
pp. 490-496 ◽  
Author(s):  
Julianne L. Holleran ◽  
Julien Fourcade ◽  
Merrill J. Egorin ◽  
Julie L. Eiseman ◽  
Robert A. Parise ◽  
...  
Keyword(s):  
Kinase Inhibitor ◽  
Carbonyl Reductase ◽  
In Vitro Metabolism ◽  
Phosphatidylinositol 3 Kinase ◽  
Phosphatidylinositol 3

scholarly journals In Vitro Antimetastatic Effect of Phosphatidylinositol 3-Kinase Inhibitor ZSTK474 on Prostate Cancer PC3 Cells

2013 ◽  
Vol 14 (7) ◽  
pp. 13577-13591 ◽  
Author(s):  
Wennan Zhao ◽  
Wenzhi Guo ◽  
Qianxiang Zhou ◽  
Sheng-Nan Ma ◽  
Ran Wang ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Kinase Inhibitor ◽  
Phosphatidylinositol 3 Kinase ◽  
Antimetastatic Effect ◽  
Pc3 Cells ◽  
Phosphatidylinositol 3

Phosphatidylinositol 3-kinase in cumulus cells is responsible for both suppression of spontaneous maturation and induction of gonadotropin-stimulated maturation of porcine oocytes

2003 ◽  
Vol 179 (1) ◽  
pp. 25-34 ◽  
Author(s):  
M Shimada ◽  
J Ito ◽  
Y Yamashita ◽  
T Okazaki ◽  
N Isobe
Keyword(s):  
High Activity ◽  
Cell Function ◽  
Kinase Inhibitor ◽  
Germinal Vesicle ◽  
Cumulus Cells ◽  
Basic Medium ◽  
Phosphatidylinositol 3 Kinase ◽  
Germinal Vesicle Breakdown ◽  
Phosphatidylinositol 3

In this study, we investigated the mechanisms of protein kinase B (PKB) activation and its role in cumulus cells during in vitro meiotic resumption of porcine oocytes. PKB activity in cumulus cells was significantly decreased by 12 h cultivation of cumulus-oocyte complexes (COCs) in basic medium. However, the addition of phosphodiesterase inhibitors, hypoxanthine or 3-isobutyl-1-methylxanthine, maintained the level of PKB activity in cumulus cells at comparable with that in cumulus cells just after collection from their follicles. When COCs were cultured with phosphatidylinositol 3-kinase (PI 3-kinase) inhibitor, LY294002, PKB activity was significantly decreased, and both caspase 3 activity and the proportion of apoptotic cells were significantly increased as compared with those in cumulus cells just after collection from their follicles. Moreover, the inhibitory effect of hypoxanthine on spontaneous meiotic resumption was overcome by addition of LY294002. On the other hand, markedly high activity of PKB and high intensity of the phosphorylated PKB band were observed in cumulus cells of COCs which were cultured with FSH. The addition of 20 microM LY294002 to FSH-containing medium induced an apoptosis of cumulus cells, whereas little apoptotic-positive signal was detected in COCs cultured with 5 microM LY294002 and FSH. However, the inhibitory effects of LY294002 on progesterone production by cumulus cells and germinal vesicle breakdown in oocytes reached a maximum at 5 microM. Thus, high activity of the PI 3-kinase-PKB pathway in cumulus cells plays an important role in FSH regulation of cell function. Judging from these results, it is estimated that PI 3-kinase in cumulus cells is required for both the suppression of spontaneous meiotic resumption and the induction of gonadotropin-stimulated meiotic resumption.

scholarly journals Wortmannin alters the transferrin receptor endocytic pathway in vivo and in vitro.

1996 ◽  
Vol 7 (3) ◽  
pp. 355-367 ◽  
Author(s):  
D J Spiro ◽  
W Boll ◽  
T Kirchhausen ◽  
M Wessling-Resnick
Keyword(s):  
Transferrin Receptor ◽  
Kinase Inhibitor ◽  
Morphological Changes ◽  
Endocytic Pathway ◽  
Receptor Internalization ◽  
Phosphatidylinositol 3 Kinase ◽  
Vitro Assay ◽  
Phosphatidylinositol 3

Treatment with the phosphatidylinositol 3-kinase inhibitor wortmannin promotes approximately 30% decrease in the steady-state number of cell-surface transferrin receptors. This effect is rapid and dose dependent, with maximal down-regulation elicited with 30 min of treatment and with an IC50 approximately 25 nM wortmannin. Wortmannin-treated cells display an increased endocytic rate constant for transferrin internalization and decreased exocytic rate constants for transferrin recycling. In addition to these effects in vivo, wortmannin is a potent inhibitor (IC50 approximately 15 nM) of a cell-free assay that detects the delivery of endocytosed probes into a common compartment. Inhibition of the in vitro assay involves the inactivation of a membrane-associated factor that can be recruited onto the surface of vesicles from the cytosol. Its effects on the cell-free assay suggest that wortmannin inhibits receptor sorting and/or vesicle budding required for delivery of endocytosed material to "mixing" endosomes. This idea is consistent with morphological changes induced by wortmannin, which include the formation of enlarged transferrin-containing structures and the disruption of the perinuclear endosomal compartment. However, the differential effects of wortmannin, specifically increased transferrin receptor internalization and inhibition of receptor recycling, implicate a role for phosphatidylinositol 3-kinase activity in multiple sorting events in the transferrin receptor's membrane traffic pathway.

scholarly journals The Identification of Raptor as a Substrate for p44/42 MAPK

Endocrinology ◽  
2011 ◽  
Vol 152 (4) ◽  
pp. 1264-1273 ◽  
Author(s):  
Paul Langlais ◽  
Zhengping Yi ◽  
Lawrence J. Mandarino
Keyword(s):  
Kinase Inhibitor ◽  
Mammalian Target Of Rapamycin ◽  
Adaptor Protein ◽  
Phosphorylation Sites ◽  
Phosphatidylinositol 3 Kinase ◽  
Mtor Inhibition ◽  
Mtor Complex 1 ◽  
Mapk Inhibitor ◽  
Phosphatidylinositol 3

Abstract The adaptor protein raptor is the functional identifier for mammalian target of rapamycin (mTOR) complex 1 (mTORC1), acting to target mTOR to specific substrates for phosphorylation and regulation. Using HPLC-electrospray ionization tandem mass spectrometry, we confirmed the phosphorylation of raptor at Ser696, Thr706, Ser721, Ser722, Ser855, Ser859, Ser863, Thr865, Ser877, Ser881, Ser883, and Ser884 and identified Tyr692, Ser699, Thr700, Ser704, Ser854, Ser857, Ser882, Ser886, Ser887, and Thr889 as new, previously unidentified raptor phosphorylation sites. Treatment of cells with insulin increased the phosphorylation of raptor at Ser696, Ser855, Ser863, and Thr865 and suppressed the phosphorylation of Ser722. Ser696 phosphorylation was insensitive to mTOR inhibition with rapamycin, whereas treatment of cells with the MAPK inhibitor PD98059 inhibited the insulin-stimulated phosphorylation of raptor at Ser696. In vitro incubation of raptor with p42 MAPK significantly increased raptor phosphorylation (P < 0.01), whereas phosphorylation of a Ser696Ala mutant was decreased (P < 0.05), suggesting MAPK is capable of directly phosphorylating raptor at Ser696. Mutation of Ser696 to alanine interfered with insulin-stimulated phosphorylation of the mTOR downstream substrate p70S6 kinase. Incubation of cells with the MAPK inhibitor PD98059 and the phosphatidylinositol 3-kinase inhibitor wortmannin decreased the insulin stimulated phosphorylation of raptor, suggesting that the MAPK and phosphatidylinositol 3-kinase pathways may merge at mTORC1.

Gallic acid promotes the in vitro development of sheep secondary isolated follicles involving the phosphatidylinositol 3-kinase pathway

2021 ◽  
pp. 106767
Author(s):  
Gizele A.L. Silva ◽  
Luana B. Araújo ◽  
Larissa C.R. Silva ◽  
Bruna B. Gouveia ◽  
Ricássio S. Barberino ◽  
...  
Keyword(s):  
Gallic Acid ◽  
Phosphatidylinositol 3 Kinase ◽  
In Vitro Development ◽  
Vitro Development ◽  
Kinase Pathway ◽  
Phosphatidylinositol 3
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