title: Selective release of a processed form of interleukin 1 alpha.
abstract: Interleukin 1 alpha (IL-1 alpha) is synthesized as a 33 kDa form and proteolytically processed into a 17 kDa form. Although IL-1 alpha has no signal peptide, it is released from cells. To investigate the relationship between the processing and release of IL-1 alpha, human bladder carcinoma cells (HTB9 5637) which express IL-1 alpha constitutively, were treated with calcium ionophore (A23187). A23187 induced the processing of 33 kDa IL-1 alpha and selectively released processed 17 kDa IL-1 alpha, without any change in the release of 33 kDa IL-1 alpha. When extracellular calcium was chelated by EGTA, or when intracellular calpain was inhibited by the cell-permeable cysteine-protease inhibitor, E64d, the processing of 33 kDa IL-1 alpha was significantly blocked, the release of 33 kDa IL-1 alpha being unchanged. These results indicate that the release of IL-1 alpha was accompanied by the processing of 33 kDa IL-1 alpha.
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: D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D002154:Calpain / Q000037:antagonists & inhibitors; D002460:Cell Line; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D004533:Egtazic Acid / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects*; D006801:Humans; D007375:Interleukin-1 / Q000096:biosynthesis* / Q000378:metabolism; D007770:L-Lactate Dehydrogenase / Q000032:analysis; D007930:Leucine / Q000031:analogs & derivatives / Q000494:pharmacology; D008715:Methionine / Q000378:metabolism; D008970:Molecular Weight; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D013462:Sulfur Radioisotopes; D014407:Tumor Cells, Cultured; D001749:Urinary Bladder Neoplasms
chemical_list: D015853:Cysteine Proteinase Inhibitors; D007375:Interleukin-1; D013462:Sulfur Radioisotopes; D000001:Calcimycin; D004533:Egtazic Acid; D008715:Methionine; D007770:L-Lactate Dehydrogenase; D002154:Calpain; D007930:Leucine; C108192:aloxistatin; D002118:Calcium