PAP-1, a novel target protein of phosphorylation by pim-1 kinase.
Protooncogene, pim-1, has been reported to be a predisposition for lymphomagenesis along with myc, and its protein product, Pim-1, has been shown to be a serine/threonine protein kinase, whose activity is involved in proliferation and differentiation of blood cells. The signal transduction pathways neither to nor from Pim-1, however, have been clarified. We have cloned a cDNA encoding a novel Pim-1 binding protein, PAP-1, comprising 213 amino acids with a basic amino-acid cluster near the C-terminus. PAP-1 was colocalized with Pim-1 in human HeLa cell nuclei. The in vitro binding assays using GST fusion proteins of the wild-type and various deletion mutants revealed that the whole molecule of Pim-1 is required for the binding activity to PAP-1 and that Pim-1 binds to the region from amino-acid numbers 1-147 of PAP-1, or to two segments in the region. The association of PAP-1 with Pim-1 was also shown in vivo in transfected cells. Furthermore, PAP-1 was phosphorylated in vitro by Pim-1, but not a kinase-negative Pim-1 mutant. The two serine residues of PAP-1 at amino acids 204 and 206 near the C-terminus were phosphorylated by Pim-1. PAP-1 is thus thought to be a target protein for Pim-1 kinase.
Department of Molecular Biology, Hokkaido University, Kita-ku, Sapporo, Japan. hiro@pharm.hokudai.ac.jp
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H
Maita
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Harada
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D
Nagakubo
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Kitaura
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M
Ikeda
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Tamai
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K
Takahashi
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Ariga
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Iguchi-Ariga
D000595:Amino Acid Sequence; D000818:Animals; D017304:Annexin A5 / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D019556:COS Cells; D003001:Cloning, Molecular; D006801:Humans; D019169:Jurkat Cells; D007700:Kinetics; D008969:Molecular Sequence Data; D000073718:Pancreatitis-Associated Proteins; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051573:Proto-Oncogene Proteins c-pim-1; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D020298:U937 Cells
D017304:Annexin A5; D000073718:Pancreatitis-Associated Proteins; D011518:Proto-Oncogene Proteins; C000612141:REG3A protein, human; D011994:Recombinant Proteins; C496634:PIM1 protein, human; D017346:Protein Serine-Threonine Kinases; D051573:Proto-Oncogene Proteins c-pim-1