title: Roles of the phosphorylation of human interleukin 1 alpha in proteolytic processing.
abstract: To investigate the role of phosphorylation of a precursor form of interleukin-1 alpha (pre-IL-1 alpha), we obtained cells producing either phosphorylated or unphosphorylated pre-IL-1 alpha. Although calcium-dependent proteolytic processing of unphosphorylated pre-IL-1 alpha could be observed in cell lysates, proteolytic processing was not induced by treatment with calcium ionophore in intact cells producing the unphosphorylated pre-IL-1 alpha. Further, unphosphorylated pre-IL-1 alpha showed no calcium-dependent binding to acidic phospholipids at concentrations below 5 x 10(-6) M. These results suggested that phosphorylated pre-IL-1 alpha became susceptible to proteolytic processing by association with the cell membrane in a calcium-dependent manner.
authors.affiliation: Department of Biomolecular Science, Faculty of Science, Toho University, Chiba, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Watanabe
authors.forename: Y
authors.initials: Y
authors.lastname: Kobayashi
mesh_terms: D016475:3T3 Cells; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology; D010450:Endopeptidases / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007375:Interleukin-1 / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000494:pharmacology; D051379:Mice; D008969:Molecular Sequence Data; D010743:Phospholipids; D010766:Phosphorylation; D011498:Protein Precursors / Q000378:metabolism; D014357:Trypsin / Q000378:metabolism
chemical_list: D007375:Interleukin-1; D008070:Lipopolysaccharides; D010743:Phospholipids; D011498:Protein Precursors; D000001:Calcimycin; D010450:Endopeptidases; D014357:Trypsin; D002118:Calcium