title: Purification and molecular cloning of SH2- and SH3-containing inositol polyphosphate-5-phosphatase, which is involved in the signaling pathway of granulocyte-macrophage colony-stimulating factor, erythropoietin, and Bcr-Abl.
abstract: Grb2/Ash and Shc are the adapter proteins that link tyrosine-kinase receptors to Ras and make tyrosine-kinase functionally associated with receptors and Ras in fibroblasts and hematopoietic cells. Grb2/Ash and Shc have the SH3, SH2, or phosphotyrosine binding domains. These domains bind to proteins containing proline-rich regions or tyrosine-phosphorylated proteins and contribute to the association of Grb2/Ash and Shc with other signaling molecules. However, there could remain unidentified signaling molecules that physically and functionally interact with these adapter proteins and have biologically important roles in the signaling pathways. By using the GST fusion protein including the full length of Grb2/Ash, we have found that c-Cbl and an unidentified 135-kD protein (pp135) are associated with Grb2/Ash. We have also found that they become tyrosine-phosphorylated by treatment of a human leukemia cell line, UT-7, with granulocyte-macrophage colony-stimulating factor (GM-CSF). We have purified the pp135 by using GST-Grb2/Ash affinity column and have isolated the full-length complementary DNA (cDNA) encoding the pp135 using a cDNA probe, which was obtained by the degenerate polymerase chain reaction based on a peptide sequence of the purified pp135. The cloned cDNA has 3,958 nucleotides that contain a single long open reading frame of 3,567 nucleotides, encoding a 1,189 amino acid protein with a predicted molecular weight of approximately 133 kD. The deduced amino acid sequence reveals that pp135 is a protein that has one SH2, one SH3, and one proline-rich domain. The pp135, which contains two motifs conserved among the inositol polyphosphate-5-phosphatase proteins, was shown to have the inositol polyphosphate-5-phosphatase activity. The pp135 was revealed to associate constitutively with Grb2/Ash and inducibly with Shc using UT-7 cells stimulated with GM-CSF. In the cell lines derived from human chronic myelogenous leukemia, pp135 was constitutively tyrosine-phosphorylated and associated with Shc and Bcr-Abl. These facts suggest that pp135 is a signaling molecule that has a unique enzymatic activity and should play an important role in the signaling pathway triggered by GM-CSF and in the transformation of hematopoietic cells caused by Bcr-Abl.
authors.affiliation: Third Department of Internal Medicine, Faculty of Medicine, University of Tokyo, Bunyo-ku, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Odai
authors.forename: K
authors.initials: K
authors.lastname: Sasaki
authors.forename: A
authors.initials: A
authors.lastname: Iwamatsu
authors.forename: T
authors.initials: T
authors.lastname: Nakamoto
authors.forename: H
authors.initials: H
authors.lastname: Ueno
authors.forename: T
authors.initials: T
authors.lastname: Yamagata
authors.forename: K
authors.initials: K
authors.lastname: Mitani
authors.forename: Y
authors.initials: Y
authors.lastname: Yazaki
authors.forename: H
authors.initials: H
authors.lastname: Hirai
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D000595:Amino Acid Sequence; D001483:Base Sequence; D002471:Cell Transformation, Neoplastic / Q000235:genetics; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D004921:Erythropoietin / Q000502:physiology*; D016044:Fusion Proteins, bcr-abl / Q000502:physiology*; D051380:GRB2 Adaptor Protein; D005796:Genes; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000502:physiology*; D006801:Humans; D007947:Leukemia, Megakaryoblastic, Acute / Q000473:pathology; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000235:genetics; D000072183:Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases; D010744:Phosphoric Monoester Hydrolases / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D010766:Phosphorylation; D019000:Phosphotyrosine / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D011506:Proteins / Q000502:physiology; D011518:Proto-Oncogene Proteins / Q000502:physiology; D050721:Proto-Oncogene Proteins c-cbl; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D055765:Shc Signaling Adaptor Proteins; D015398:Signal Transduction / Q000502:physiology*; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D014407:Tumor Cells, Cultured; D044767:Ubiquitin-Protein Ligases; D018909:src Homology Domains
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D018076:DNA, Complementary; D051380:GRB2 Adaptor Protein; C495948:GRB2 protein, human; D009363:Neoplasm Proteins; D011506:Proteins; D011518:Proto-Oncogene Proteins; D011993:Recombinant Fusion Proteins; C528024:SHC1 protein, human; D055765:Shc Signaling Adaptor Proteins; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D004921:Erythropoietin; D019000:Phosphotyrosine; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D050721:Proto-Oncogene Proteins c-cbl; D044767:Ubiquitin-Protein Ligases; D016044:Fusion Proteins, bcr-abl; D010744:Phosphoric Monoester Hydrolases; C098706:INPPL1 protein, human; D000072183:Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases; C067419:CBL protein, human