Fibronectin phosphorylation by ecto-protein kinase

Journal Article · Thu Dec 01 04:00:00 EST 1988 · Experimental Cell Research; (United States)

DOI:https://doi.org/10.1016/0014-4827(88)90293-5· OSTI ID:5451375

Imada, Sumi; Sugiyama, Yayoi; Imada, Masaru ^[1]

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1. Meiji Institute of Health Science, Odawara (Japan)

The presence of membrane-associated, extracellular protein kinase (ecto-protein kinase) and its substrate proteins was examined with serum-free cultures of Swiss 3T3 fibroblast. When cells were incubated with ({gamma}-{sup 32})ATP for 10 min at 37{degree}C, four proteins with apparent molecular weights between 150 and 220 kDa were prominently phosphorylated. These proteins were also radiolabeled by lactoperoxidase catalyzed iodination and were sensitive to mild tryptic digestion, suggesting that they localized on the cell surface or in the extracellular matrix. Phosphorylation of extracellular proteins with ({gamma}-{sup 32}P)ATP in intact cell culture is consistent with the existence of ecto-protein kinase. Anti-fibronectin antibody immunoprecipitated one of the phosphoproteins which comigrated with a monomer and a dimer form of fibronectin under reducing and nonreducing conditions of electrophoresis, respectively. The protein had affinity for gelatin as demonstrated by retention with gelatin-conjugated agarose. This protein substrate of ecto-protein kinase was thus concluded to be fibronectin. The sites of phosphorylation by ecto-protein kinase were compared with those of intracellularly phosphorylated fibronectin by the analysis of radiolabeled amino acids and peptides. Ecto-protein kinase phosphorylated fibronectin at serine and threonine residues which were distinct from the sites of intracellular fibronectin phosphorylation.

• OSTI ID: 5451375
• Journal Information: Experimental Cell Research; (United States), Journal Name: Experimental Cell Research; (United States) Vol. 179:2; ISSN ECREA; ISSN 0014-4827
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALKALI METAL COMPOUNDS
AMINO ACIDS
ANIMAL CELLS
ANIMALS
ATP
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMISTRY
CARBOXYLIC ACIDS
CELL CONSTITUENTS
CELL MEMBRANES
CHEMICAL REACTIONS
CHEMISTRY
CONNECTIVE TISSUE CELLS
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
ELECTROPHORESIS
ENZYMES
FIBROBLASTS
HALIDES
HALOGEN COMPOUNDS
HALOGENATION
HYDROXY ACIDS
INORGANIC PHOSPHORS
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
IODIDES
IODINATION
IODINE 125
IODINE COMPOUNDS
IODINE ISOTOPES
ISOTOPES
LIGHT NUCLEI
MAMMALS
MEMBRANE PROTEINS
MEMBRANES
MICE
NUCLEI
NUCLEOTIDES
ODD-EVEN NUCLEI
ODD-ODD NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
OXIDOREDUCTASES
PEROXIDASES
PHOSPHORS
PHOSPHORUS 32
PHOSPHORUS ISOTOPES
PHOSPHORUS-GROUP TRANSFERASES
PHOSPHORYLATION
PHOSPHOTRANSFERASES
PROTEINS
RADIOISOTOPES
RECEPTORS
RODENTS
SCLEROPROTEINS
SERINE
SODIUM COMPOUNDS
SODIUM IODIDES
SOMATIC CELLS
SUBSTRATES
THREONINE
TRANSFERASES
VERTEBRATES