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A Tyrosine Kinase Signaling Pathway Accounts for the Majority of Phosphatidylinositol 3,4,5-Trisphosphate Formation in Chemoattractant-stimulated Human Neutrophils*

  • Andrzej Ptasznik
    Correspondence
    To whom correspondence should be addressed:
    Affiliations
    From the Departments of Immunology and
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  • Eric R. Prossnitz
    Affiliations
    From the Departments of Immunology and
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  • Dan Yoshikawa
    Affiliations
    Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, New York 14642, and the
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  • Alan Smrcka
    Affiliations
    Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, New York 14642, and the
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  • Alexis E. Traynor-Kaplan
    Affiliations
    Department of Medicine, University of California, San Diego, La Jolla, California 92037
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  • Gary M. Bokoch
    Correspondence
    To whom correspondence should be addressed
    Affiliations
    Cell Biology, The Scripps Research Institute, La Jolla, California 92037, the
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  • Author Footnotes
    * This work was supported by National Institutes of Health Grants GM44428 and GM39434 (to G. M. B.), DK47240 (to A. T. K.), and AI36357 (to E. R. P.) and a PhRMA Foundation Research Starter grant (to A. S.), as well as a Miles and Shirley Fitterman Research Award (to A. T. K.). This is publication 10100-IMM from The Scripps Research Institute. The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
Open AccessPublished:October 11, 1996DOI:https://doi.org/10.1074/jbc.271.41.25204
      The signaling pathway leading from G protein-coupled chemoattractant receptors to the generation of oxidants by NADPH oxidase in human neutrophils requires the formation of the lipid mediator phosphatidylinositol 3,4,5-trisphosphate (PIP3). Two mechanisms through which PIP3 can be generated have been described in human leukocytes. One pathway involves the coupling of the src-related tyrosine kinase Lyn to the “classical” p85/p110 form of phosphatidylinositol 3-kinase. The second paradigm utilizes a novel form of phosphatidylinositol 3-kinase whose activity is directly regulated by G protein βγ subunits. In this paper, we show that formation of PIP3 in chemoattractant-stimulated neutrophils is substantially attenuated by inhibitors that specifically block tyrosine kinase activity. These data suggest that the Lyn activation pathway plays a major role in the formation of this important lipid messenger during chemoattractant stimulation of human neutrophils.

      INTRODUCTION

      Phosphatidylinositol 3-kinase (PI3K)
      The abbreviations used are: PI3K
      phosphatidylinositol 3-kinase
      PIP3
      phosphatidylinositol 3,4,5-trisphosphate
      fMLP
      formylmethionylleucylphenylalanine.
      has been shown to be an important mediator of intracellular signaling in mammalian cells (reviewed in
      • Divecha N.
      • Irvine R.F.
      ,
      • Kazlauskas A.
      ,
      • Downes C.P.
      • Carter A.N.
      ). The major product of PI3K, PIP3, is generated by phosphorylation of phosphatidylinositol 4,5-bisphosphate at the 3ʹ position of the inositol ring. Formation of PIP3 has been correlated with both cytoskeletal regulation and mitogenic signaling by growth factors (
      • Divecha N.
      • Irvine R.F.
      ,
      • Kazlauskas A.
      ,
      • Downes C.P.
      • Carter A.N.
      ). In human leukocytes, studies using PI3K inhibitors indicate that PIP3 formation is a critical component of the signaling pathway leading from chemoattractant receptors to oxidant production by the NADPH oxidase (
      • Traynor-Kaplan A.E.
      • Thompson B.L.
      • Harris A.L.
      • Taylor P.
      • Omann G.M.
      • Sklar L.A.
      ,
      • Stephens L.R.
      • Hughes K.T.
      • Irvine R.F.
      ,
      • Stephens L.
      • Jackson T.
      • Hawkins P.T.
      ,
      • Stephens L.
      • Equinoa A.
      • Corey S.
      • Jackson T.
      • Hawkins T.
      ,
      • Thelen M.
      • Wirthmueller U.
      ,
      • Arcaro A.
      • Wymann M.P.
      ,
      • Vlahos C.J.
      • Matter W.F.
      • Brown R.F.
      • Traynor-Kaplan A.E.
      • Heyworth P.G.
      • Prossnitz E.R.
      • Ye R.D.
      • Marder P.
      • Schelm J.A.
      • Rothfuss K.J.
      • Serlin B.S.
      • Simpson P.J.
      ). Formation of PIP3 via PI3K was originally described in chemoattractant-stimulated human neutrophils (
      • Traynor-Kaplan A.E.
      • Harris A.L.
      • Thompson B.L.
      • Taylor P.
      • Sklar L.A.
      ), and this has remained one of the best characterized cellular systems in terms of PI3K activation by G protein-coupled receptors.
      Two types of PIP3-generating enzymes have been described in neutrophils. The “classical” form of the enzyme consists of a p110 catalytic subunit and a p85 regulatory subunit (
      • Escobedo J.A.
      • Navankasattusas S.
      • Kavanaugh W.M.
      • Milfray D.
      • Fried V.A.
      • Williams L.T.
      ,
      • Skolnik E.Y.
      • Margolis B.
      • Mohamnudi M.
      • Lowenstein E.
      • Fischer R.
      • Drepps A.
      • Ullrich A.
      • Schlessinger J.
      ,
      • Otsu M.
      • Hiles I.
      • Gout I.
      • Fry M.J.
      • Ruiz-Larrea F.
      • Panayotou G.
      • Thompson A.
      • Dhanal R.
      • Hsuan J.
      • Totty N.
      • Smith A.D.
      • Morgan S.J.
      • Courtneidge S.A.
      • Parker P.J.
      • Waterfield M.D.
      ). This ubiquitous PI3K can be activated by a number of mechanisms in various cell types (
      • Divecha N.
      • Irvine R.F.
      ,
      • Kazlauskas A.
      ,
      • Downes C.P.
      • Carter A.N.
      ,
      • Thelen M.
      • Wirthmueller U.
      ). These mechanisms include binding of the enzyme to tyrosine-phosphorylated motifs of growth factor receptors via SH2 domains on the p85 subunit (
      • Divecha N.
      • Irvine R.F.
      ,
      • Kazlauskas A.
      ,
      • Hiles I.D.
      • Otsu M.
      • Volinia S.
      • Fry M.J.
      • Gout I.
      • Dhaml R.
      • Panayotou G.
      • Ruiz-Larvea F.
      • Thompson A.
      • Totty N.F.
      • Hsuan J.J.
      • Courtneidge S.A.
      • Parker P.J.
      • Waterfield M.D.
      ,
      • Carpenter C.L.
      • Auger K.R.
      • Chanudhuri M.
      • Yoakim M.
      • Schaffhausen B.
      • Shoelson S.
      • Cantley L.C.
      ,
      • Rordorf-Nikolic T.
      • Van Horn D.J.
      • Chen D.
      • White M.F.
      • Backer J.M.
      ) and activation of the enzyme by binding of Src-family kinase SH3 domains to proline-rich domains on the p85 subunit (
      • Pleiman C.M.
      • Hertz W.M.
      • Cambier J.C.
      ). Additionally, small GTPases of the Ras and Rho families can stimulate enzyme activity (
      • Rodriguez-Viciana P.
      • Warne P.H.
      • Vanhaesebroeck B.
      • Gout I.
      • Fry M.J.
      • Waterfield M.D.
      • Downward J.
      ,
      • Zheng Y.
      • Bagrodia S.
      • Cerione R.A.
      ,
      • Tolias K.F.
      • Cantley L.C.
      • Carpenter C.L.
      ,
      • Bokoch G.M.
      • Vlahos C.J.
      • Wang Y.
      • Knaus U.G.
      • Traynor-Kaplan A.E.
      ). Recently, a novel form of PI3K has been described in myeloid cells whose activity is directly regulated by G protein βγ subunits (
      • Stephens L.
      • Smrcka A.
      • Cooke F.T.
      • Jackson T.R.
      • Sternweis P.C.
      • Hawkins P.T.
      ,
      • Thomason P.A.
      • Janes S.R.
      • Casey P.J.
      • Downes C.P.
      ). This form of PI3K has now been cloned and shown to consist of a unique p110γ catalytic subunit that lacks the p85 binding domain and therefore does not associate with the p85 subunit (
      • Stoyanov B.
      • Volinia S.
      • Hanck T.
      • Rubio I.
      • Loubtchenkov M.
      • Malek D.
      • Stoyanova S.
      • Vanhaesebroeck B.
      • Dhand R.
      • Nürnberg B.
      • Gierschik P.
      • Seedorf K.
      • Hsuan J.J.
      • Waterfield M.D.
      • Wetzker R.
      ).
      The N-formyl peptide chemoattractant receptor couples to cell activation via heterotrimeric pertussis toxin-sensitive Gi proteins (
      • Bokoch G.M.
      ). As a result of Gi activation by receptor, Gβγ subunits are released and can regulate a number of enzymatic activities, including the formation of IP3 and diacylglycerol via activation of PLC-β isoforms (
      • Camps M.
      • Hou C.
      • Sidiropoulos D.
      • Stock J.B.
      • Jakobs K.H.
      • Gierschik P.
      ,
      • Camps M.
      • Carozzi A.
      • Schnabel P.
      • Scheer A.
      • Parker P.J.
      • Gierschik P.
      ,
      • Katz A.
      • Wu D.
      • Simon H.I.
      ,
      • Smrcka A.V.
      • Sternweis P.C.
      ). The apparently abundant (
      • Stephens L.
      • Smrcka A.
      • Cooke F.T.
      • Jackson T.R.
      • Sternweis P.C.
      • Hawkins P.T.
      ) Gβγ-regulated PI3K would presumably be activated as well. An additional signaling pathway activated by this receptor utilizes the Lyn tyrosine kinase (
      • Stephens L.
      • Equinoa A.
      • Corey S.
      • Jackson T.
      • Hawkins T.
      ,
      • Ptasznik A.
      • Traynor-Kaplan A.
      • Bokoch G.M.
      ). In N-formyl peptide-stimulated cells, Lyn physically and temporally associates with the classical p85/p110 form of PI3K (
      • Ptasznik A.
      • Traynor-Kaplan A.
      • Bokoch G.M.
      ). A similar situation has been observed with the B cell antigen receptor, where binding of Lyn through its SH3 domain to the p85 subunit directly activates PI3K (
      • Pleiman C.M.
      • Hertz W.M.
      • Cambier J.C.
      ). An important question that has not yet been resolved is the contribution of the Lyn-regulated PI3K pathway versus that of the Gβγ-regulated enzyme to the overall formation of PIP3 in chemoattractant-stimulated neutrophils. This question is of importance for understanding the actual signaling mechanisms that couple these receptors to generation of active oxidants for the purpose of bacterial killing. In this study, we present data that indicate that a tyrosine kinase-dependent pathway presumably mediated via Lyn accounts for a majority of the PIP3 formed in response to N-formyl peptide receptor activation.

      DISCUSSION

      We previously demonstrated that the Shc adapter protein was phosphorylated on tyrosine in response to chemoattractant receptor activation and that this phosphorylated Shc was physically associated with Lyn (
      • Ptasznik A.
      • Traynor-Kaplan A.
      • Bokoch G.M.
      ). In the present study, we provide further evidence that Shc is tyrosine-phosphorylated by Lyn by demonstrating that blockade of Lyn tyrosine kinase activity inhibits Shc phosphorylation (Fig. 1). This is consistent with our results showing that the interaction of Lyn and Shc occurs via a Shc SH2 domain (
      • Ptasznik A.
      • Traynor-Kaplan A.
      • Bokoch G.M.
      ).
      The data presented here strongly indicate that the Lyn-regulated PI3K pathway of PIP3 formation is of primary importance quantitatively during chemoattractant-mediated leukocyte activation. We have previously shown that the enhancement of PI3K activity associated with Lyn immunoprecipitates is rapid and parallels both PIP3 formation and cell activation (
      • Traynor-Kaplan A.E.
      • Thompson B.L.
      • Harris A.L.
      • Taylor P.
      • Omann G.M.
      • Sklar L.A.
      ,
      • Ptasznik A.
      • Traynor-Kaplan A.
      • Bokoch G.M.
      ). This is in contrast to the data of Stephens et al. (
      • Stephens L.
      • Equinoa A.
      • Corey S.
      • Jackson T.
      • Hawkins T.
      ), who reported Lyn-associated PIP3 formation was much slower. The Src tyrosine kinase inhibitor radicicol substantially attenuated the rise in PIP3 formation stimulated by the chemoattractant fMetLeuPhe at a concentration that totally blocked stimulated Lyn tyrosine kinase activity (Fig. 2). This inhibition was not due to a direct inhibitory effect on either the p85/p110 PI3K or the βγ-regulated enzyme (Table I), nor was there any nonspecific inhibition of βγ-mediated signaling in general (Fig. 3). Because there is no involvement of nor requirement for a tyrosine kinase in activating the βγ-regulated enzyme (
      • Stephens L.
      • Smrcka A.
      • Cooke F.T.
      • Jackson T.R.
      • Sternweis P.C.
      • Hawkins P.T.
      ,
      • Thomason P.A.
      • Janes S.R.
      • Casey P.J.
      • Downes C.P.
      ,
      • Stoyanov B.
      • Volinia S.
      • Hanck T.
      • Rubio I.
      • Loubtchenkov M.
      • Malek D.
      • Stoyanova S.
      • Vanhaesebroeck B.
      • Dhand R.
      • Nürnberg B.
      • Gierschik P.
      • Seedorf K.
      • Hsuan J.J.
      • Waterfield M.D.
      • Wetzker R.
      ), our data strongly point to the Lyn pathway as a quantitatively important source of PIP3 during early neutrophil activation. Radicicol inhibited the increase in cellular PIP3 levels by nearly 70%, indicating that at least two-thirds of the PIP3 formed originated from a tyrosine kinase-regulated PI3K pathway rather than from the βγ-regulated enzyme. Indeed, if the decrease in actual mass of PIP3 product formed is considered, the level of inhibition is even greater. An alternative explanation for our results would have to invoke the need for a tyrosine kinase for in vivo activation of the βγ-regulated PI3K, a hypothesis for which there is no supporting evidence.
      The predominant importance of the tyrosine kinase-requiring PI3K pathway is also evidenced by the data we obtained with genistein. Although not as clearcut as the radicicol data, we observed that genistein almost completely blocked (>90%) chemoattractant-stimulated PIP3 formation while not decreasing unstimulated levels of PIP3. Even taking into account the inhibition that could occur due to direct effects on PI3K itself (30-40% in vitro), the majority of the inhibition appears to be as a result of tyrosine kinase blockade. The observation that genistein was a direct inhibitor of the βγ-sensitive PI3K (p110γ) at higher concentrations may have bearing on the widespread use of this compound as a specific inhibitor of tyrosine kinases (
      • Akiyama T.
      • Ishida J.
      • Nakagawa S.
      • Ogawara H.
      • Watanabe S.
      • Itoh N.
      • Shibuya M.
      • Fukami Y.
      ). It is clear that at higher concentrations genistein can interact with the p110γ and the p85-associated p110 isoforms (α, β) as well (
      • Matter W.F.
      • Brown R.F.
      • Vlahos C.J.
      ). This is likely to be due to the ability of genistein to compete with ATP for binding to the enzyme (
      • Akiyama T.
      • Ishida J.
      • Nakagawa S.
      • Ogawara H.
      • Watanabe S.
      • Itoh N.
      • Shibuya M.
      • Fukami Y.
      ). Because radicicol is structurally distinct from genistein and inhibits tyrosine kinases in a manner noncompetitive with ATP (
      • Kwon J.J.
      • Yoshida M.
      • Abe K.
      • Horinouchi S.
      • Beppu T.
      ,
      • Kwon H.J.
      • Yoshida M.
      • Fukui Y.
      • Horinouchi S.
      • Beppu T.
      ), it has no effect on either form of PI3K.
      In summary, we have provided evidence that a tyrosine kinase-requiring pathway likely to be the Lyn pathway is quantitatively predominant for formation of the lipid mediator PIP3 during early leukocyte activation by chemoattractants. Thus, the regulation of neutrophil functions that depend upon PIP3 formation, such as oxidant formation via the NADPH oxidase (
      • Arcaro A.
      • Wymann M.P.
      ,
      • Vlahos C.J.
      • Matter W.F.
      • Brown R.F.
      • Traynor-Kaplan A.E.
      • Heyworth P.G.
      • Prossnitz E.R.
      • Ye R.D.
      • Marder P.
      • Schelm J.A.
      • Rothfuss K.J.
      • Serlin B.S.
      • Simpson P.J.
      ), is likely to occur via the tyrosine kinase-initiated pathway. The Rac GTPase is a critical regulator of the NADPH oxidase (
      • Bokoch G.M.
      ), and we have previously shown that Rac translocation from cytosolic complex to membrane oxidase requires the activity of a tyrosine kinase (
      • Dorseuil O.
      • Quinn M.T.
      • Bokoch G.M.
      ). PI3K activity has also been implicated in Rac activation (
      • Wennstr÷m S.
      • Hawkins P.
      • Cooke F.
      • Hara K.
      • Yonezawa K.
      • Kasuga M.
      • Jackson T.
      • Claesson-Welsh L.
      • Stephens L.
      ). The data presented here reconcile these observations by demonstrating the primary importance of the tyrosine kinase mechanism for generating the lipid mediator PIP3 in chemoattractant-stimulated human neutrophils.

      Acknowledgments

      We thank Eleanora Wolfson for expert technical assistance. Antonette Lestelle is gratefully acknowledged for help in manuscript preparation.

      REFERENCES

        • Divecha N.
        • Irvine R.F.
        Cell. 1995; 80: 269-278
        • Kazlauskas A.
        Curr. Opin. Genet. & Dev. 1994; 4: 5-14
        • Downes C.P.
        • Carter A.N.
        Cell. Signal. 1991; 3: 501-513
        • Traynor-Kaplan A.E.
        • Thompson B.L.
        • Harris A.L.
        • Taylor P.
        • Omann G.M.
        • Sklar L.A.
        J. Biol. Chem. 1989; 264: 15668-15673
        • Stephens L.R.
        • Hughes K.T.
        • Irvine R.F.
        Nature. 1991; 351: 33-39
        • Stephens L.
        • Jackson T.
        • Hawkins P.T.
        J. Biol. Chem. 1993; 268: 17162-17172
        • Stephens L.
        • Equinoa A.
        • Corey S.
        • Jackson T.
        • Hawkins T.
        EMBO J. 1993; 12: 2265-2273
        • Thelen M.
        • Wirthmueller U.
        Curr. Opin. Immunol. 1994; 6: 106-112
        • Arcaro A.
        • Wymann M.P.
        Biochem. J. 1993; 296: 297-301
        • Vlahos C.J.
        • Matter W.F.
        • Brown R.F.
        • Traynor-Kaplan A.E.
        • Heyworth P.G.
        • Prossnitz E.R.
        • Ye R.D.
        • Marder P.
        • Schelm J.A.
        • Rothfuss K.J.
        • Serlin B.S.
        • Simpson P.J.
        J. Immunol. 1995; 154: 2413-2422
        • Traynor-Kaplan A.E.
        • Harris A.L.
        • Thompson B.L.
        • Taylor P.
        • Sklar L.A.
        Nature. 1988; 334: 353-356
        • Escobedo J.A.
        • Navankasattusas S.
        • Kavanaugh W.M.
        • Milfray D.
        • Fried V.A.
        • Williams L.T.
        Cell. 1991; 65: 75-82
        • Skolnik E.Y.
        • Margolis B.
        • Mohamnudi M.
        • Lowenstein E.
        • Fischer R.
        • Drepps A.
        • Ullrich A.
        • Schlessinger J.
        Cell. 1991; 65: 83-90
        • Otsu M.
        • Hiles I.
        • Gout I.
        • Fry M.J.
        • Ruiz-Larrea F.
        • Panayotou G.
        • Thompson A.
        • Dhanal R.
        • Hsuan J.
        • Totty N.
        • Smith A.D.
        • Morgan S.J.
        • Courtneidge S.A.
        • Parker P.J.
        • Waterfield M.D.
        Cell. 1992; 65: 91-104
        • Hiles I.D.
        • Otsu M.
        • Volinia S.
        • Fry M.J.
        • Gout I.
        • Dhaml R.
        • Panayotou G.
        • Ruiz-Larvea F.
        • Thompson A.
        • Totty N.F.
        • Hsuan J.J.
        • Courtneidge S.A.
        • Parker P.J.
        • Waterfield M.D.
        Cell. 1992; 70: 419-429
        • Carpenter C.L.
        • Auger K.R.
        • Chanudhuri M.
        • Yoakim M.
        • Schaffhausen B.
        • Shoelson S.
        • Cantley L.C.
        J. Biol. Chem. 1993; 268: 9478-9483
        • Rordorf-Nikolic T.
        • Van Horn D.J.
        • Chen D.
        • White M.F.
        • Backer J.M.
        J. Biol. Chem. 1995; 270: 3662-3666
        • Pleiman C.M.
        • Hertz W.M.
        • Cambier J.C.
        Science. 1994; 263: 1609-1612
        • Rodriguez-Viciana P.
        • Warne P.H.
        • Vanhaesebroeck B.
        • Gout I.
        • Fry M.J.
        • Waterfield M.D.
        • Downward J.
        Nature. 1994; 370: 527-532
        • Zheng Y.
        • Bagrodia S.
        • Cerione R.A.
        J. Biol. Chem. 1994; 269: 18727-18730
        • Tolias K.F.
        • Cantley L.C.
        • Carpenter C.L.
        J. Biol. Chem. 1995; 270: 17656-17659
        • Bokoch G.M.
        • Vlahos C.J.
        • Wang Y.
        • Knaus U.G.
        • Traynor-Kaplan A.E.
        Biochem. J. 1996; 315: 775-779
        • Stephens L.
        • Smrcka A.
        • Cooke F.T.
        • Jackson T.R.
        • Sternweis P.C.
        • Hawkins P.T.
        Cell. 1994; 77: 83-93
        • Thomason P.A.
        • Janes S.R.
        • Casey P.J.
        • Downes C.P.
        J. Biol. Chem. 1994; 269: 16525-16528
        • Stoyanov B.
        • Volinia S.
        • Hanck T.
        • Rubio I.
        • Loubtchenkov M.
        • Malek D.
        • Stoyanova S.
        • Vanhaesebroeck B.
        • Dhand R.
        • Nürnberg B.
        • Gierschik P.
        • Seedorf K.
        • Hsuan J.J.
        • Waterfield M.D.
        • Wetzker R.
        Science. 1995; 269: 690-693
        • Bokoch G.M.
        Grinstein S. Rotstein O.D. Current Topics in Membranes and Transport. Academic Press, Orlando, FL1991: 65
        • Camps M.
        • Hou C.
        • Sidiropoulos D.
        • Stock J.B.
        • Jakobs K.H.
        • Gierschik P.
        Eur. J. Biochem. 1992; 206: 821-831
        • Camps M.
        • Carozzi A.
        • Schnabel P.
        • Scheer A.
        • Parker P.J.
        • Gierschik P.
        Nature. 1992; 360: 684-686
        • Katz A.
        • Wu D.
        • Simon H.I.
        Nature. 1992; 360: 686-689
        • Smrcka A.V.
        • Sternweis P.C.
        J. Biol. Chem. 1993; 268: 9667-9674
        • Ptasznik A.
        • Traynor-Kaplan A.
        • Bokoch G.M.
        J. Biol. Chem. 1995; 270: 19969-19973
        • Dobos G.J.
        • Norgauer J.
        • Eberle M.
        • Schollmeyer P.J.
        • Traynor-Kaplan A.
        J. Immunol. 1992; 149: 609-614
        • Dorseuil O.
        • Quinn M.T.
        • Bokoch G.M.
        J. Leukocyte Biol. 1995; 58: 108-113
        • Sternweis P.C.
        • Robishaw J.D.
        J. Biol. Chem. 1984; 259: 13806-13813
        • Vlahos C.J.
        • Matter W.F.
        FEBS Lett. 1992; 309: 242-248
        • Matter W.F.
        • Brown R.F.
        • Vlahos C.J.
        Biochem. Biophys. Res. Commun. 1992; 186: 624-631
        • Kwon J.J.
        • Yoshida M.
        • Abe K.
        • Horinouchi S.
        • Beppu T.
        Biosci. Biotechnol. Biochem. 1992; 56: 538-539
        • Kwon H.J.
        • Yoshida M.
        • Fukui Y.
        • Horinouchi S.
        • Beppu T.
        Cancer Res. 1992; 52: 6926-6930
        • Chanmugam P.
        • Feng L.
        • Liou S.
        • Jang B.C.
        • Boudreau M.
        • Yu G.
        • Lee J.H.
        • Kwon H.J.
        • Beppu T.
        • Yoshida M.
        • Xia Y.
        • Wilson C.B.
        • Hwang D.
        J. Biol. Chem. 1995; 270: 5418-5426
        • Cockroft S.
        Biochim. Biophys. Acta. 1992; 1113: 135-160
        • Thelen M.
        • Dewald B.
        • Baggiolini M.
        Physiol. Rev. 1993; 73: 797-821
        • Lew D.P.
        • Krause K.
        Curr. Opin. Hematol. 1993; 1993: 106-112
        • Akiyama T.
        • Ishida J.
        • Nakagawa S.
        • Ogawara H.
        • Watanabe S.
        • Itoh N.
        • Shibuya M.
        • Fukami Y.
        J. Biol. Chem. 1987; 262: 5592-5595
        • Bokoch G.M.
        Curr. Opin. Cell Biol. 1994; 6: 212-218
        • Wennstr÷m S.
        • Hawkins P.
        • Cooke F.
        • Hara K.
        • Yonezawa K.
        • Kasuga M.
        • Jackson T.
        • Claesson-Welsh L.
        • Stephens L.
        Curr. Biol. 1994; 4: 385-393