Abstract
CD45, a leukocyte-specific transmembrane protein tyrosine phosphatase, mediates signal transduction pathways critical for immune responses. However, the mechanism of CD45-mediated signal transduction and the identity of CD45-associated proteins have remained unclear. A CD45-associated 30-kDA phosphorylated protein (CD45-AP) was purified by virtue of its specific association with CD45, and its mouse cDNA was cloned by using the internal amino acid sequence information. In vitro translated CD45-AP bound specifically to CD45. CD45-AP appears to be leukocyte-specific and shares no significant homology with presently known sequences. The predicted sequence contains no consensus tyrosine phosphorylation sites or conserved sequences of GTP-binding proteins. CD45-AP may act as an adapter molecule for CD45-mediated signal transduction.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Amino Acid Sequence
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Animals
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Base Sequence
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Blotting, Southern
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Cell Line
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Chromatography, Affinity
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Cloning, Molecular / methods
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DNA, Complementary / biosynthesis
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DNA, Complementary / metabolism
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Gene Library
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Intracellular Signaling Peptides and Proteins
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Kinetics
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Leukocyte Common Antigens / metabolism*
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Leukocytes / metabolism
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Male
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Membrane Proteins*
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Mice
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Mice, Inbred BALB C
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Molecular Sequence Data
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Molecular Weight
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Organ Specificity
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Phosphoproteins / biosynthesis*
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Phosphoproteins / isolation & purification
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Phosphoproteins / metabolism
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Protein Binding
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Protein Biosynthesis
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RNA, Messenger / metabolism
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Recombinant Proteins / biosynthesis
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Recombinant Proteins / isolation & purification
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Recombinant Proteins / metabolism
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Restriction Mapping
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T-Lymphocytes
Substances
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DNA, Complementary
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Intracellular Signaling Peptides and Proteins
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Membrane Proteins
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Phosphoproteins
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Ptprcap protein, mouse
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RNA, Messenger
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Recombinant Proteins
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Leukocyte Common Antigens