scholarly journals Identification of amino acid residues required for a specific interaction between Src-tyrosine kinase and proline-rich region of phosphatidylinositol-3′ kinase

FEBS Letters ◽  
1996 ◽  
Vol 397 (2-3) ◽  
pp. 183-185 ◽  
Author(s):  
Paul Mak ◽  
Zhiqing He ◽  
Tomohiro Kurosaki
Keyword(s):  
Amino Acid ◽  
Tyrosine Kinase ◽  
Specific Interaction ◽  
Amino Acid Residues ◽  
Phosphatidylinositol 3 Kinase ◽  
Rich Region ◽  
Src Tyrosine Kinase ◽  
Proline Rich Region ◽  
Phosphatidylinositol 3

scholarly journals Requirement of phosphatidylinositol 3-kinase-dependent pathway and Src for Gas6-Axl mitogenic and survival activities in NIH 3T3 fibroblasts.

1997 ◽  
Vol 17 (8) ◽  
pp. 4442-4453 ◽  
Author(s):  
S Goruppi ◽  
E Ruaro ◽  
B Varnum ◽  
C Schneider
Keyword(s):  
Tyrosine Kinase ◽  
Specific Inhibitor ◽  
S Phase ◽  
Phosphatidylinositol 3 Kinase ◽  
3T3 Cells ◽  
Src Tyrosine Kinase ◽  
Survival Effect ◽  
Nih 3T3 ◽  
Nih 3T3 Cells ◽  
Phosphatidylinositol 3

Gas6 is a secreted protein previously identified as the ligand of the Axl receptor tyrosine kinase. We have shown that Gas6 is able to induce cell cycle reentry of serum-starved NIH 3T3 cells and to efficiently prevent apoptosis after complete growth factor removal, a survival effect uncoupled from Gas6-induced mitogenesis. Here we report that the mitogenic effect of Gas6 requires phosphatidylinositol 3-kinase (PI3K) activity since it is abrogated both by the specific inhibitor wortmannin and by overexpression of the dominant negative P13K p85 subunit. Consistently, Gas6 activates the P13K downstream targets S6K and Akt, whose activation is abrogated by addition of wortmannin. Moreover, rapamycin treatment blocks Gas6-induced entry into the S phase of serum-starved NIH 3T3 cells. We also demonstrate the requirement of Src tyrosine kinase for Gas6 signalling since stable or transient expression of a catalytically inactive form of Src significantly inhibited Gas6-stimulated entry into the S phase. Accordingly, Gas6 addition to serum-starved NIH 3T3 cells causes activation of the intrinsic Src kinase activity. When specifically analyzed in a survival assay, these elements were found to be required for the survival effect of Gas6. Taken together, the evidence presented here identifies elements involved in the Gas6 transduction pathway that are responsible for its antiapoptotic effect and suggests that Src is involved in the events regulating cell survival.

scholarly journals Phosphatidylinositol 3-kinase binds to α-actinin through the p85 subunit

1994 ◽  
Vol 302 (2) ◽  
pp. 551-557 ◽  
Author(s):  
F Shibasaki ◽  
K Fukami ◽  
Y Fukui ◽  
T Takenawa
Keyword(s):  
Signal Transduction ◽  
Kinase Activity ◽  
Cytoskeletal Reorganization ◽  
Phosphatidylinositol 3 Kinase ◽  
3T3 Cells ◽  
Rich Region ◽  
Phosphatidylinositol 4 ◽  
Nih 3T3 ◽  
Proline Rich Region ◽  
Phosphatidylinositol 3

Phosphatidylinositol 3-kinase (PI 3-kinase) has been shown to play an important role in the signal transduction of cell growth. It is also suggested that it is involved in cytoskeletal reorganization. We have found that alpha-actinin copurifies with PI 3-kinase from bovine thymus. The antibody against PI 3-kinase 85 kDa subunit (p85) also co-immunoprecipitates alpha-actinin from lysates of NIH/3T3 cells. In addition, anti-alpha-actinin antibody coprecipitates PI 3-kinase activity. This coprecipitation was observed even after depolymerization of actin fibres, suggesting that PI 3-kinase binds directly to alpha-actinin. As alpha-actinin is a phosphatidylinositol 4,5-bisphosphate (PI4,5P2)-binding protein, binding experiments using various constructs of truncated p85 were carried out in the presence or absence of PI4,5P2. In the absence of PI4,5P2, chicken gizzard alpha-actinin binds only to the whole p85 construct, but it binds to the proline-rich region of p85 fragments in the presence of PI4,5P2. This binding is enhanced with increased concentrations of Pi4,5P2 up to 10 microM, whereas phosphatidylinositol and phosphatidylinositol 4-phosphate were not good activators of alpha-actinin binding. These results suggest that PI 3-kinase binds to alpha-actinin and regulates cytoskeletal reorganization.

Determination of Amino Acid Residues Responsible for Specific Interaction of Protein Kinases with Small Molecule Inhibitors

2018 ◽  
Vol 52 (3) ◽  
pp. 478-487 ◽  
Author(s):  
D. A. Karasev ◽  
A. V. Veselovsky ◽  
A. A. Lagunin ◽  
D. A. Filimonov ◽  
B. N. Sobolev
Keyword(s):  
Amino Acid ◽  
Protein Kinases ◽  
Small Molecule ◽  
Small Molecule Inhibitors ◽  
Specific Interaction ◽  
Amino Acid Residues

Schizosaccharomyces pombe Vps34p, a phosphatidylinositol-specific PI 3-kinase essential for normal cell growth and vacuole morphology

1995 ◽  
Vol 108 (12) ◽  
pp. 3745-3756 ◽  
Author(s):  
K. Takegawa ◽  
D.B. DeWald ◽  
S.D. Emr
Keyword(s):  
Amino Acid ◽  
Schizosaccharomyces Pombe ◽  
Mammalian Cells ◽  
Membrane Fraction ◽  
Kinase Activity ◽  
Temperature Sensitive ◽  
Wild Type ◽  
Phosphatidylinositol 3 Kinase ◽  
Acid Protein ◽  
Phosphatidylinositol 3

We have cloned the gene, vps34+, from the fission yeast Schizosaccharomyces pombe which encodes an 801 amino acid protein with phosphatidylinositol 3-kinase activity. The S. pombe Vps34 protein shares 43% amino acid sequence identity with the Saccharomyces cerevisiae Vps34 protein and 28% identity with the p110 catalytic subunit of the mammalian phosphatidylinositol 3-kinase. When the vps34+ gene is disrupted, S.pombe strains are temperature-sensitive for growth and the mutant cells contain enlarged vacuoles. Furthermore, while wild-type strains exhibit substantial levels of phosphatidylinositol 3-kinase activity, this activity is not detected in the vps34 delta strain. S.pombe Vps34p-specific antiserum detects a single protein in cells of -90 kDa that fractionates almost exclusively with the crude membrane fraction. Phosphatidylinositol 3-kinase activity also is localized mainly in the membrane fraction of wild-type cells. Immunoisolated Vps34p specifically phosphorylates phosphatidylinositol on the D-3 position of the inositol ring to yield phosphatidylinositol(3)phosphate. but does not utilize phosphatidylinositol(4)phosphate or phosphatidylinositol(4,5)bisphosphate as substrates. In addition, when compared to the mammalian p110 phosphatidylinositol 3-kinase, S. pombe Vps34p is relatively insensitive to the inhibitors wortmannin and LY294002. Together, these results indicate that S. pombe Vps34 is more similar to the phosphatidylinositol-specific 3-kinase, Vps34p from S. cerevisiae, and is distinct from the p110/p85 and G protein-coupled phosphatidylinositol 3-kinases from mammalian cells. These data are discussed in relation to the possible role of Vps34p in vesicle-mediated protein sorting to the S. pombe vacuole.

Hepatic glutamine transporter activation in burn injury: role of amino acids and phosphatidylinositol-3-kinase

2000 ◽  
Vol 278 (4) ◽  
pp. G532-G541 ◽  
Author(s):  
Timothy M. Pawlik ◽  
Rüdiger Lohmann ◽  
Wiley W. Souba ◽  
Barrie P. Bode
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Burn Injury ◽  
Cell Swelling ◽  
Phosphatidylinositol 3 Kinase ◽  
Pi3k Inhibitors ◽  
Glutamine Transporter ◽  
Hypermetabolic State ◽  
Phosphatidylinositol 3

Burn injury elicits a marked, sustained hypermetabolic state in patients characterized by accelerated hepatic amino acid metabolism and negative nitrogen balance. The transport of glutamine, a key substrate in gluconeogenesis and ureagenesis, was examined in hepatocytes isolated from the livers of rats after a 20% total burn surface area full-thickness scald injury. A latent and profound two- to threefold increase in glutamine transporter system N activity was first observed after 48 h in hepatocytes from injured rats compared with controls, persisted for 9 days, and waned toward control values after 18 days, corresponding with convalescence. Further studies showed that the profound increase was fully attributable to rapid posttranslational transporter activation by amino acid-induced cell swelling and that this form of regulation may be elicited in part by glucagon. The phosphatidylinositol-3-kinase (PI3K) inhibitors wortmannin and LY-294002 each significantly attenuated transporter stimulation by amino acids. The data suggest that PI3K-dependent system N activation by amino acids may play an important role in fueling accelerated hepatic nitrogen metabolism after burn injury.

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