title: A new negatively regulated acute-phase phosphoprotein synthesized by rat hepatocytes.
abstract: The effect of acute inflammation on the production of the major phosphorylated protein (PP63) excreted by rat hepatocytes was investigated. Both intra- and extracellular forms of the protein labelled with [32P]Pi, [3H]fucose and [35S]methionine were immunoprecipitated with monospecific polyclonal antibodies, and relative rates of PP63 synthesis were measured. The hepatocytes of acutely inflamed rats produced and excreted 85% less 32P- and 3H-labelled PP63 than did control cells. This decreased amount of PP63 did not result from an impairment in the phosphorylation or glycosylation processes or from a blockade in excretion, but rather was found to be due to extensive shut-off in biosynthesis of the protein as measured by [35S]methionine incorporation. Thus PP63 would appear to represent a new negatively regulated acute-phase protein.
mesh_terms: D000209:Acute-Phase Proteins; D000818:Animals; D011232:Chemical Precipitation; D004591:Electrophoresis, Polyacrylamide Gel; D005110:Extracellular Space / Q000378:metabolism; D005643:Fucose / Q000378:metabolism; D007249:Inflammation; D008099:Liver / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D008297:Male; D008715:Methionine / Q000378:metabolism; D010710:Phosphates / Q000378:metabolism; D010750:Phosphoproteins / Q000096:biosynthesis* / Q000276:immunology; D010766:Phosphorylation; D051381:Rats
chemical_list: D000209:Acute-Phase Proteins; D010710:Phosphates; D010750:Phosphoproteins; C047026:acute-phase phosphoprotein pp63; D005643:Fucose; D008715:Methionine