Abstract
Palmitylation of Src family tyrosine kinases has been shown to play a role in directing their membrane localization. Here we demonstrate that palmitylation can also regulate recognition and tyrosine phosphorylation of the B cell Src kinase substrate Ig alpha. Blk and Src, which are not palmitylated, phosphorylate co-expressed Ig alpha in Cos cells, whereas palmitylated Src kinases do not. Addition of a palmitylation site to Blk abrogates its phosphorylation of the substrate, while mutation of Fyn's palmitylation sites results in recognition and phosphorylation of Ig alpha. These results indicate that palmitylation, a reversible protein modification, aids in regulating recognition of physiologic substrates by Src family tyrosine kinases.
Publication types
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Research Support, Non-U.S. Gov't
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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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Antigens, CD / chemistry
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Antigens, CD / metabolism
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B-Lymphocytes / immunology
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B-Lymphocytes / metabolism*
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CD79 Antigens
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COS Cells
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Mutagenesis, Site-Directed
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Palmitic Acids / chemistry
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Palmitic Acids / metabolism*
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Phosphorylation
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Proto-Oncogene Proteins / metabolism
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Proto-Oncogene Proteins c-fyn
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Receptors, Antigen, B-Cell / chemistry
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Receptors, Antigen, B-Cell / metabolism
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Recombinant Fusion Proteins / chemistry
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Recombinant Fusion Proteins / genetics
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Recombinant Fusion Proteins / metabolism
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Signal Transduction
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Substrate Specificity
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Transfection
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src-Family Kinases / chemistry*
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src-Family Kinases / genetics
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src-Family Kinases / metabolism*
Substances
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Antigens, CD
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CD79 Antigens
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Palmitic Acids
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Proto-Oncogene Proteins
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Receptors, Antigen, B-Cell
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Recombinant Fusion Proteins
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Proto-Oncogene Proteins c-fyn
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src-Family Kinases