B cell receptor-mediated nuclear fragmentation proceeds in WEHI 231 cells in the absence of detectable DEVDase and FRase activity.
Crosslinking of the WEHI 231 lymphoma B cell receptor (BCR) leads to growth arrest followed by apoptosis. In a study of the role of lysosomal cysteine proteinases in BCR-mediated apoptosis we provide evidence that commitment to apoptosis correlates with a time-dependent increase in caspase and cathepsin activities. We also show that activation of cathepsins is a caspase-independent process, and caspase cascade activation is independent of lysosomal endopeptidases. BCR-induced nuclear fragmentation was not prevented, but rather delayed in the absence of detectable caspase and cathepsin activities, suggesting that BCR-driven apoptosis of these cells may use an alternative proteolytic mechanism independent of caspases and cathepsins.
Mlinaric-Rascan
Irena
I
Faculty of Pharmacy, University of Ljubljana, Slovenia. irena.mlinaric@ffa.uni-lj.si
Turk
Boris
B
D000906:Antibodies / Q000378:metabolism*; D017209:Apoptosis / Q000187:drug effects; D001402:B-Lymphocytes / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism; D002403:Cathepsins / Q000037:antagonists & inhibitors / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D053938:DNA Fragmentation / Q000187:drug effects; D004789:Enzyme Activation; D006801:Humans; D007075:Immunoglobulin M / Q000378:metabolism*; D007930:Leucine / Q000031:analogs & derivatives* / Q000494:pharmacology; D010447:Peptide Hydrolases / Q000378:metabolism*; D011480:Protease Inhibitors / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D000906:Antibodies; D061945:Caspase Inhibitors; D007075:Immunoglobulin M; D011480:Protease Inhibitors; D002403:Cathepsins; D010447:Peptide Hydrolases; D020169:Caspases; D003546:Cysteine Endopeptidases; C108711:DEVDase; D007930:Leucine; C108192:aloxistatin