Abstract
Anaplastic large-cell lymphoma is a subtype of non-Hodgkin lymphomas characterized by the expression of CD30. More than half of these lymphomas carry a chromosomal translocation t(2;5) leading to expression of the oncogenic tyrosine kinase nucleophosmin-anaplastic lymphoma kinase (NPM-ALK). NPM-ALK is capable of transforming fibroblasts and lymphocytes in vitro and of causing lymphomas in mice. Previously, we and others demonstrated phospholipase C-gamma and phosphatidylinositol 3-kinase as crucial downstream signaling mediators of NPM-ALK-induced oncogenicity. In this study, we used an ALK fusion protein as bait in a yeast two-hybrid screen identifying NIPA (nuclear interacting partner of ALK) as a novel downstream target of NPM-ALK. NIPA encodes a 60-kDa protein that is expressed in a broad range of human tissues and contains a classical nuclear translocation signal in its C terminus, which directs its nuclear localization. NIPA interacts with NPM-ALK and other ALK fusions in a tyrosine kinase-dependent manner and is phosphorylated in NPM-ALK-expressing cells on tyrosine and serine residues with serine 354 as a major phosphorylation site. Overexpression of NIPA in Ba/F3 cells was able to protect from apoptosis induced by IL-3 withdrawal. Mutations of the nuclear translocation signal or the Ser-354 phosphorylation site impaired the antiapoptotic function of NIPA. In NPM-ALK-transformed Ba/F3 cells, apoptosis triggered by wortmannin treatment was enhanced by overexpression of putative dominant-negative NIPA mutants. These results implicate an antiapoptotic role for NIPA in NPM-ALK-mediated signaling events.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Active Transport, Cell Nucleus
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Adaptor Proteins, Signal Transducing
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Amino Acid Sequence
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Androstadienes / pharmacology
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Animals
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Apoptosis
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Blotting, Northern
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COS Cells
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Cell Cycle
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Cell Cycle Proteins
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Cell Line
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Cell Nucleus / metabolism*
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Cloning, Molecular
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DNA, Complementary / metabolism
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Electrophoresis, Polyacrylamide Gel
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Enzyme Inhibitors / pharmacology
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Fibroblasts / metabolism
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Glutathione Transferase / metabolism
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Humans
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Immunoblotting
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In Situ Nick-End Labeling
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Ki-1 Antigen / biosynthesis
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Lymphoma, Large B-Cell, Diffuse / metabolism*
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Mice
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Microscopy, Fluorescence
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Models, Biological
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Molecular Sequence Data
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Mutation
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Nuclear Proteins / chemistry*
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Nuclear Proteins / metabolism*
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Phosphatidylinositol 3-Kinases / metabolism*
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Phosphoamino Acids / metabolism
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Phospholipase C gamma
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Phosphorylation
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Plasmids / metabolism
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Protein Binding
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Protein Structure, Tertiary
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Protein-Tyrosine Kinases / chemistry
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Protein-Tyrosine Kinases / metabolism*
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RNA, Messenger / metabolism
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Recombinant Fusion Proteins / metabolism
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Sequence Homology, Amino Acid
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Serine / chemistry
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Signal Transduction
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Time Factors
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Tissue Distribution
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Transfection
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Two-Hybrid System Techniques
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Type C Phospholipases / chemistry*
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Tyrosine / chemistry
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Wortmannin
Substances
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Adaptor Proteins, Signal Transducing
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Androstadienes
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Cell Cycle Proteins
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DNA, Complementary
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Enzyme Inhibitors
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Ki-1 Antigen
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NIPA protein, mouse
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Nuclear Proteins
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Phosphoamino Acids
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RNA, Messenger
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Recombinant Fusion Proteins
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ZC3HC1 protein, human
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Tyrosine
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Serine
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Glutathione Transferase
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Phosphatidylinositol 3-Kinases
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p80(NPM-ALK) protein
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Protein-Tyrosine Kinases
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Type C Phospholipases
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Phospholipase C gamma
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Wortmannin
Associated data
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GENBANK/AF537494
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GENBANK/AF537495