Characterization of the 78 kDa mast cell protein phosphorylated by the antiallergic drug cromolyn and homology to moesin.

摘要: Abstract Mast cells (MC) can be stimulated to secrete by cross-linking immunoglobulin E bound specific surface receptors, as well in response polycationic molecules such substance P and compound 48 80 . The antiallergic drug disodium cromoglycate (cromolyn) inhibited MC secretion rapidly incorporated phosphate into a 78 kDa protein, speculated its mode of action. This protein was purified single two-dimensional gel electrophoresis, shown phosphorylated primarily on serine residues kinase C. Partial amino acid sequencing two generated fragments identical that portions mouse moesin, member the band 4.1 superfamily proteins, with no definitive function known date. Polyclonal antibodies raised against rat basophil leukemia cell moesin cDNA expressed Escherichia coli immunoprecipitated phosphoprotein quantitatively, immunocytochemistry localized it plasma membrane. Reversible phosphorylation this could affect possible cytoskeletal binding through which may regulate stimulus-secretion coupling MC.