title: Caspase-12 processing and fragment translocation into nuclei of tunicamycin-treated cells.
abstract: Excess endoplasmic reticulum (ER) stress induces processing of caspase-12, which is located in the ER, and cell death. However, little is known about the relationship between caspase-12 processing and cell death. We prepared antisera against putative caspase-12 cleavage sites (anti-m12D318 and anti-m12D341) and showed that overexpression of caspase-12 induced autoprocessing at D(318) but did not induce cell death. Mutation analysis confirmed that D(318) was a unique autoprocessing site. In contrast, tunicamycin, one of the ER stress stimuli, induced caspase-12 processing at the N-terminal region and the C-terminal region (both at D(318) and D(341)) and cell death. Anti-m12D318 and anti-m12D341 immunoreactivities were located in the ER of the tunicamycin-treated cells, and some immunoreactivities were located around and in the nuclei of the apoptotic cells. Thus, processing at the N-terminal region may be necessary for the translocation of processed caspase-12 into nuclei and cell death induced by ER stress. Some of the caspase-12 processed at the N-terminal and C-terminal regions may directly participate in the apoptotic events in nuclei.
authors.affiliation: Divisions of Development and Differentiation, National Institute of Neuroscience, NCNP, Kodaira, Tokyo, Japan.
authors.forename: E
authors.initials: E
authors.lastname: Fujita
authors.forename: Y
authors.initials: Y
authors.lastname: Kouroku
authors.forename: A
authors.initials: A
authors.lastname: Jimbo
authors.forename: A
authors.initials: A
authors.lastname: Isoai
authors.forename: K
authors.initials: K
authors.lastname: Maruyama
authors.forename: T
authors.initials: T
authors.lastname: Momoi
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D000906:Antibodies / Q000276:immunology; D019556:COS Cells; D053454:Caspase 12; D020169:Caspases / Q000235:genetics / Q000378:metabolism*; D020134:Catalytic Domain / Q000187:drug effects / Q000276:immunology; D002467:Cell Nucleus / Q000187:drug effects / Q000201:enzymology*; D004721:Endoplasmic Reticulum / Q000187:drug effects / Q000201:enzymology*; D005057:Eukaryotic Cells / Q000187:drug effects / Q000201:enzymology*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects / Q000502:physiology; D007150:Immunohistochemistry; D017434:Protein Structure, Tertiary / Q000187:drug effects / Q000235:genetics; D018000:Receptors, Peptide / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics; D013312:Stress, Physiological / Q000201:enzymology* / Q000235:genetics; D014415:Tunicamycin / Q000494:pharmacology
chemical_list: D000906:Antibodies; C064459:KDEL receptor; D018000:Receptors, Peptide; D011993:Recombinant Fusion Proteins; D014415:Tunicamycin; D053454:Caspase 12; D020169:Caspases