Publications

• Inositol polyphosphate 5-phosphatase7 regulates the production of reactive oxygen species and salt tolerance in Arabidopsis.

  Kaye Y., Golani Y., Singer Y., Leshem Y., Cohen G., Ercetin M., Gillaspy G., Levine A.

  Plants possess remarkable ability to adapt to adverse environmental conditions. The adaptation process involves the removal of many molecules from organelles, especially membranes, and replacing them with new ones. The process is mediated by an intracellular vesicle-trafficking system regulated by ... >> More

  Plants possess remarkable ability to adapt to adverse environmental conditions. The adaptation process involves the removal of many molecules from organelles, especially membranes, and replacing them with new ones. The process is mediated by an intracellular vesicle-trafficking system regulated by phosphatidylinositol (PtdIns) kinases and phosphatases. Although PtdIns comprise a fraction of membrane lipids, they function as major regulators of stress signaling. We analyzed the role of PtdIns 5-phosphatases (5PTases) in plant salt tolerance. The Arabidopsis (Arabidopsis thaliana) genome contains 15 At5PTases. We analyzed salt sensitivity in nine At5ptase mutants and identified one (At5ptase7) that showed increased sensitivity, which was improved by overexpression. At5ptase7 mutants demonstrated reduced production of reactive oxygen species (ROS). Supplementation of mutants with exogenous PtdIns dephosphorylated at the D5' position restored ROS production, while PtdIns(4,5)P(2), PtdIns(3,5)P(2), or PtdIns(3,4,5)P(3) were ineffective. Compromised salt tolerance was also observed in mutant NADPH Oxidase, in agreement with the low ROS production and salt sensitivity of PtdIns 3-kinase mutants and with the inhibition of NADPH oxidase activity in wild-type plants. Localization of green fluorescent protein-labeled At5PTase7 occurred in the plasma membrane and nucleus, places that coincided with ROS production. Analysis of salt-responsive gene expression showed that mutants failed to induce the RD29A and RD22 genes, which contain several ROS-dependent elements in their promoters. Inhibition of ROS production by diphenylene iodonium suppressed gene induction. In summary, our results show a nonredundant function of At5PTase7 in salt stress response by regulating ROS production and gene expression. << Less

  Plant Physiol. 157:229-241(2011) [PubMed] [EuropePMC]

• The 145-kDa protein induced to associate with Shc by multiple cytokines is an inositol tetraphosphate and phosphatidylinositol 3,4,5-triphosphate 5-phosphatase.

  Damen J.E., Liu L., Rosten P., Humphries R.K., Jefferson A.B., Majerus P.W., Krystal G.

  A 145-kDa tyrosine-phosphorylated protein that becomes associated with Shc in response to multiple cytokines has been purified from the murine hemopoietic cell line B6SUtA1. Amino acid sequence data were used to clone the cDNA encoding this protein from a B6SUtA1 library. The predicted amino acid ... >> More

  A 145-kDa tyrosine-phosphorylated protein that becomes associated with Shc in response to multiple cytokines has been purified from the murine hemopoietic cell line B6SUtA1. Amino acid sequence data were used to clone the cDNA encoding this protein from a B6SUtA1 library. The predicted amino acid sequence encodes a unique protein containing an N-terminal src homology 2 domain, two consensus sequences that are targets for phosphotyrosine binding domains, a proline-rich region, and two motifs highly conserved among inositol polyphosphate 5-phosphatases. Cell lysates immunoprecipitated with antiserum to this protein exhibited both phosphatidylinositol 3,4,5-trisphosphate and inositol 1,3,4,5-tetrakisphosphate polyphosphate 5-phosphatase activity. This novel signal transduction intermediate may serve to modulate both Ras and inositol signaling pathways. Based on its properties, we suggest the 145-kDa protein be called SHIP for SH2-containing inositol phosphatase. << Less

  Proc. Natl. Acad. Sci. U.S.A. 93:1689-1693(1996) [PubMed] [EuropePMC]

• SHIP-2 and PTEN are expressed and active in vascular smooth muscle cell nuclei, but only SHIP-2 is associated with nuclear speckles.

  Deleris P., Bacqueville D., Gayral S., Carrez L., Salles J.P., Perret B., Breton-Douillon M.

  Recently, the control of phosphatidylinositol 3,4,5-trisphosphate (PtdIns(3,4,5)P3)-dependant signaling by phosphatases has emerged, but there is a shortage of information on intranuclear PtdIns(3,4,5)P3 phosphatases. Therefore, we investigated the dephosphorylation of [32P]PtdIns(3,4,5)P3 specifi ... >> More

  Recently, the control of phosphatidylinositol 3,4,5-trisphosphate (PtdIns(3,4,5)P3)-dependant signaling by phosphatases has emerged, but there is a shortage of information on intranuclear PtdIns(3,4,5)P3 phosphatases. Therefore, we investigated the dephosphorylation of [32P]PtdIns(3,4,5)P3 specifically labeled on the D-3 position of the inositol ring in membrane-free nuclei isolated from pig aorta vascular smooth muscle cells (VSMCs). In vitro PtdIns(3,4,5)P3 phosphatase assays revealed the production of both [32P]PtdIns(3,4)P2 and inorganic phosphate, demonstrating the presence of PtdIns(3,4,5)P3 5- and 3-phosphatase activities inside the VSMC nucleus, respectively. Both activities presented the same potency in cellular lysates, whereas the nuclear PtdIns(3,4,5)P3 5-phosphatase activity appeared to be the most efficient. Immunoblot experiments showed for the first time the expression of the 5-phosphatase SHIP-2 (src homology 2 domain-containing inositol phosphatase) as well as the 3-phosphatase PTEN (phosphatase and tensin homolog deleted on chromosome 10) in VSMC nuclei. In addition, immunoprecipitations from nuclear fractions indicated a [32P]PtdIns(3,4,5)P3 dephosphorylation by both SHIP-2 and PTEN. Moreover, confocal microscopy analyses demonstrated that SHIP-2 but not PTEN colocalized with a speckle-specific component, the SC35 splicing factor. These results suggest that SHIP-2 may be the primary enzyme for metabolizing PtdIns(3,4,5)P3 into PtdIns(3,4)P2 within the nucleus, thus producing another second messenger, whereas PTEN could down-regulate nuclear phosphoinositide 3-kinase signaling. Finally, intranuclear PtdIns(3,4,5)P3 phosphatases might be involved in the control of VSMC proliferation and the pathogenesis of vascular proliferative disorders. << Less

  J. Biol. Chem. 278:38884-38891(2003) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.

• p150Ship, a signal transduction molecule with inositol polyphosphate-5-phosphatase activity.

  Lioubin M.N., Algate P.A., Tsai S., Carlberg K., Aebersold A., Rohrschneider L.R.

  The production, survival, and function of monocytes and macrophages is regulated by the macrophage colony-stimulating factor (M-CSF or CSF-1) through its tyrosine kinase receptor Fms. Binding of M-CSF to Fms induces the tyrosine phosphorylation and association of a 150-kD protein with the phosphot ... >> More

  The production, survival, and function of monocytes and macrophages is regulated by the macrophage colony-stimulating factor (M-CSF or CSF-1) through its tyrosine kinase receptor Fms. Binding of M-CSF to Fms induces the tyrosine phosphorylation and association of a 150-kD protein with the phosphotyrosine-binding (PTB) domain of Shc. We have cloned p150 using a modified yeast two-hybrid screen. p150 contains one SH2 domain, two potential PTB-binding sites, an ATP/GTP-binding domain, several potential SH3-binding sites, and a domain with homology to inositol polyphosphate-5-phosphatases. p150 antibodies detect this protein in FDC-P1 myeloid cells, but the same protein is not detectable in fibroblasts. The antibodies immunoprecipitate a 150-kD protein from quiescent or M-CSF-stimulated FDC-P1 cells that hydrolyzes PtdIns(3,4,5)P3, to PtdIns(3,4)P2. This activity is observed in Shc immunoprecipitates only after M-CSF stimulation. Retroviral expression of p15O in FD-Fms cells results in strong inhibition of cell growth in M-CSF and a lesser inhibition in IL-3. Ectopic expression of p150 in fibroblasts does not inhibit growth. This novel protein, p150(ship) (SH2-containing inositol phosphatase), identifies a component of a new growth factor-receptor signaling pathway in hematopoietic cells. << Less

  Genes Dev. 10:1084-1095(1996) [PubMed] [EuropePMC]

• The SH2 domain containing inositol 5-phosphatase SHIP2 displays phosphatidylinositol 3,4,5-trisphosphate and inositol 1,3,4,5-tetrakisphosphate 5-phosphatase activity.

  Pesesse X., Moreau C., Drayer A.L., Woscholski R., Parker P., Erneux C.

  Distinct forms of inositol and phosphatidylinositol polyphosphate 5-phosphatases selectively remove the phosphate from the 5-position of the inositol ring from both soluble and lipid substrates. SHIP1 is the 145-kDa SH2 domain-containing inositol 5-phosphatase expressed in haematopoietic cells. SH ... >> More

  Distinct forms of inositol and phosphatidylinositol polyphosphate 5-phosphatases selectively remove the phosphate from the 5-position of the inositol ring from both soluble and lipid substrates. SHIP1 is the 145-kDa SH2 domain-containing inositol 5-phosphatase expressed in haematopoietic cells. SHIP2 is a related but distinct gene product. We report here that SHIP2 can be expressed in an active form both in Escherichia coli and in COS-7 cells. A truncated 103-kDa recombinant protein could be purified from bacteria that display both inositol 1,3,4,5-tetrakisphosphate (InsP4) and phosphatidylinositol 3,4,5-trisphosphate (PtdIns(3,4,5)P3) phosphatase activities. COS-7 cell lysates transfected with SHIP2 had increased PtdIns(3,4,5)P3 phosphatase activity as compared to the vector alone. << Less

  FEBS Lett 437:301-303(1998) [PubMed] [EuropePMC]

• The isolation and characterization of a cDNA encoding phospholipid-specific inositol polyphosphate 5-phosphatase.

  Kisseleva M.V., Wilson M.P., Majerus P.W.

  We report the cDNA cloning and characterization of a novel human inositol polyphosphate 5-phosphatase (5-phosphatase) that has substrate specificity unlike previously described members of this large gene family. All previously described members hydrolyze water soluble inositol phosphates. This enz ... >> More

  We report the cDNA cloning and characterization of a novel human inositol polyphosphate 5-phosphatase (5-phosphatase) that has substrate specificity unlike previously described members of this large gene family. All previously described members hydrolyze water soluble inositol phosphates. This enzyme hydrolyzes only lipid substrates, phosphatidylinositol 3,4,5-trisphosphate and phosphatidylinositol 4,5-bisphosphate. The cDNA isolated comprises 3110 base pairs and predicts a protein product of 644 amino acids and M(r) = 70,023. We designate this 5-phosphatase as type IV. It is a highly basic protein (pI = 8.8) and has the greatest affinity toward phosphatidylinositol 3,4,5-trisphosphate of known 5-phosphatases. The K(m) is 0.65 micrometer, 1/10 that of SHIP (5.95 micrometer), another 5-phosphatase that hydrolyzes phosphatidylinositol 3,4,5-trisphosphate. The activity of 5-phosphatase type IV is sensitive to the presence of detergents in the in vitro assay. Thus the enzyme hydrolyzes lipid substrates in the absence of detergents or in the presence of n-octyl beta-glucopyranoside or Triton X-100, but not in the presence of cetyltriethylammonium bromide, the detergent that has been used in other studies of the hydrolysis of phosphatidylinositol 4,5-bisphosphate. Remarkably SHIP, a 5-phosphatase previously characterized as hydrolyzing only substrates with d-3 phosphates, also readily hydrolyzed phosphatidylinositol 4,5-bisphosphate in the presence of n-octyl beta-glucopyranoside but not cetyltriethylammonium bromide. We used antibodies prepared against a peptide predicted by the cDNA to identify the 5-phosphatase type IV enzyme in human tissues and find that it is highly expressed in the brain as determined by Western blotting. We also performed Western blotting of mouse tissues and found high levels of expression in the brain, testes, and heart with lower levels of expression in other tissues. mRNA was detected in many tissues and cell lines as determined by Northern blotting. << Less

  J. Biol. Chem. 275:20110-20116(2000) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.

• Cloning and expression of a human placenta inositol 1,3,4,5-tetrakisphosphate and phosphatidylinositol 3,4,5-trisphosphate 5-phosphatase.

  Drayer A.L., Pesesse X., De Smedt F., Woscholski R., Parker P., Erneux C.

  Distinct inositol and phosphatidylinositol polyphosphate 5-phosphatases have recently been cloned. Primers were designated coding for highly conserved amino acid regions that are shared between sequences of 5-phosphatases. We used degenerate primers to amplify polymerase chain reaction products fr ... >> More

  Distinct inositol and phosphatidylinositol polyphosphate 5-phosphatases have recently been cloned. Primers were designated coding for highly conserved amino acid regions that are shared between sequences of 5-phosphatases. We used degenerate primers to amplify polymerase chain reaction products from rat brain cDNA. A product with a novel sequence was identified and used to clone a 4.9 kb cDNA from human placenta cDNA libraries (hp51CN). COS-7 cells transfected with a C-terminal truncated form of this cDNA showed an increase in Ins(1,3,4,5)P4 and PtdIns(3,4,5)P3 hydrolyzing activity, but not in Ins(1,4,5)P3 5-phosphatase. Enzymatic activity was inhibited in the presence of 2,3-bisphosphoglycerate and p-hydroxymercuribenzoate. The presence of an SH2 domain and proline-rich sequence motifs within hp51CN suggests that this 5-phosphatase interacts with various proteins in signal transduction. << Less

  Biochem. Biophys. Res. Commun. 225:243-249(1996) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.

• SH3YL1 regulates dorsal ruffle formation by a novel phosphoinositide-binding domain.

  Hasegawa J., Tokuda E., Tenno T., Tsujita K., Sawai H., Hiroaki H., Takenawa T., Itoh T.

  Reversible interactions between cytosolic proteins and membrane lipids such as phosphoinositides play important roles in membrane morphogenesis driven by actin polymerization. In this paper, we identify a novel lipid-binding module, which we call the SYLF domain (after the SH3YL1, Ysc84p/Lsb4p, Ls ... >> More

  Reversible interactions between cytosolic proteins and membrane lipids such as phosphoinositides play important roles in membrane morphogenesis driven by actin polymerization. In this paper, we identify a novel lipid-binding module, which we call the SYLF domain (after the SH3YL1, Ysc84p/Lsb4p, Lsb3p, and plant FYVE proteins that contain it), that is highly conserved from bacteria to mammals. SH3YL1 (SH3 domain containing Ysc84-like 1) strongly bound to phosphatidylinositol 3,4,5-triphosphate (PI(3,4,5)P(3)) and several D5-phosphorylated phosphoinositides through its SYLF domain and was localized to circular dorsal ruffles induced by platelet-derived growth factor stimulation. Interestingly, SHIP2 (the PI(3,4,5)P(3) 5-phosphatase, src-homology 2-containing inositol-5-phosphatase 2) was identified as a binding partner of SH3YL1, and knockdown of these proteins significantly suppressed dorsal ruffle formation. Phosphatidylinositol 3,4-bisphosphate (PI(3,4)P(2)), which is mainly synthesized from PI(3,4,5)P(3) by the action of SHIP2, was enriched in dorsal ruffles, and PI(3,4)P(2) synthesis strongly correlated with formation of the circular membrane structure. These results provide new insight into the molecular mechanism of dorsal ruffle formation and its regulation by phosphoinositide metabolism. << Less

  J. Cell Biol. 193:901-916(2011) [PubMed] [EuropePMC]

• Inositol polyphosphate phosphatidylinositol 5-phosphatase9 (At5ptase9) controls plant salt tolerance by regulating endocytosis.

  Golani Y., Kaye Y., Gilhar O., Ercetin M., Gillaspy G., Levine A.

  Phosphatidylinositol 5-phosphatases (5PTases) that hydrolyze the 5' position of the inositol ring are key components of membrane trafficking system. Recently, we reported that mutation in At5PTase7 gene reduced production of reactive oxygen species (ROS) and decreased expression of stress-responsi ... >> More

  Phosphatidylinositol 5-phosphatases (5PTases) that hydrolyze the 5' position of the inositol ring are key components of membrane trafficking system. Recently, we reported that mutation in At5PTase7 gene reduced production of reactive oxygen species (ROS) and decreased expression of stress-responsive genes, resulting in increased salt sensitivity. Here, we describe an even more salt-sensitive 5ptase mutant, At5ptase9, which also hydrolyzes the 5' phosphate groups specifically from membrane-bound phosphatidylinositides. Interestingly, the mutants were more tolerant to osmotic stress. We analyzed the main cellular processes that may be affected by the mutation, such as production of ROS, influx of calcium, and induction of salt-response genes. The At5ptase9 mutants showed reduced ROS production and Ca(2+) influx, as well as decreased fluid-phase endocytosis. Inhibition of endocytosis by phenylarsine oxide or Tyrphostin A23 in wild-type plants blocked these responses. Induction of salt-responsive genes in wild-type plants was also suppressed by the endocytosis inhibitors. Thus, inhibition of endocytosis in wild-type plants mimicked the salt stress responses, observed in the At5ptase9 mutants. In summary, our results show a key non-redundant role of At5PTase7 and 9 isozymes, and underscore the localization of membrane-bound PtdIns in regulating plant salt tolerance by coordinating the endocytosis, ROS production, Ca(2+) influx, and induction of stress-responsive genes. << Less

  Mol. Plant 6:1781-1794(2013) [PubMed] [EuropePMC]

• A novel SH2-containing phosphatidylinositol 3,4,5-trisphosphate 5-phosphatase (SHIP2) is constitutively tyrosine phosphorylated and associated with src homologous and collagen gene (SHC) in chronic myelogenous leukemia progenitor cells.

  Wisniewski D., Strife A., Swendeman S., Erdjument-Bromage H., Geromanos S., Kavanaugh W.M., Tempst P., Clarkson B.

  Because of the probable causal relationship between constitutive p210(bcr/abl) protein tyrosine kinase activity and manifestations of chronic-phase chronic myelogenous leukemia (CML; myeloid expansion), a key goal is to identify relevant p210 substrates in primary chronic-phase CML hematopoietic p ... >> More

  Because of the probable causal relationship between constitutive p210(bcr/abl) protein tyrosine kinase activity and manifestations of chronic-phase chronic myelogenous leukemia (CML; myeloid expansion), a key goal is to identify relevant p210 substrates in primary chronic-phase CML hematopoietic progenitor cells. We describe here the purification and mass spectrometric identification of a 155-kD tyrosine phosphorylated protein associated with src homologous and collagen gene (SHC) from p210(bcr/abl)-expressing hematopoietic cells as SHIP2, a recently reported, unique SH2-domain-containing protein closely related to phosphatidylinositol polyphosphate 5-phosphatase SHIP. In addition to an N-terminal SH2 domain and a central catalytic region, SHIP2 (like SHIP1) possesses both potential PTB(NPXY) and SH3 domain (PXXP) binding motifs. Thus, two unique 5-ptases with striking structural homology are coexpressed in hematopoietic progenitor cells. Stimulation of human hematopoietic growth factor responsive cell lines with stem cell factor (SCF), interleukin-3 (IL-3), and granulocyte-macrophage colony-stimulating factor (GM-CSF) demonstrate the rapid tyrosine phosphorylation of SHIP2 and its resulting association with SHC. This finding suggests that SHIP2, like that reported for SHIP1 previously, is linked to downstream signaling events after activation of hematopoietic growth factor receptors. However, using antibodies specific to these two proteins, we demonstrate that, whereas SHIP1 and SHIP2 selectively hydrolyze PtdIns(3,4,5)P3 in vitro, only SHIP1 hydrolyzes soluble Ins(1,3,4,5)P4. Such an enzymatic difference raises the possibility that SHIP1 and SHIP2 may serve different functions. Preliminary binding studies using lysates from p210(bcr/abl)-expressing cells indicate that both Ptyr SHIP2 and Ptyr SHIP1 bind to the PTB domain of SHC but not to its SH2 domain. Interestingly, SHIP2 was found to selectively bind to the SH3 domain of ABL, whereas SHIP1 selectively binds to the SH3 domain of Src. Furthermore, in contrast to SHIP1, SHIP2 did not bind to either the N-terminal or C-terminal SH3 domains of GRB2. These observations suggest (1) that SHIP1 and SHIP2 may have a different hierarchy of binding SH3 containing proteins and therefore may modulate different signaling pathways and/or localize to different cellular compartments and (2) that they may be substrates for tyrosine phosphorylation by different tyrosine kinases. Because recent evidence has clearly implicated both PI(3,4, 5)P3 and PI(3,4)P2 in growth factor-mediated signaling, our finding that both SHIP1 and SHIP2 are constitutively tyrosine phosphorylated in CML primary hematopoietic progenitor cells may thus have important implications in p210(bcr/abl)-mediated myeloid expansion. << Less

  Blood 93:2707-2720(1999) [PubMed] [EuropePMC]