Inhibition of apoptosis and clonogenic survival of cells expressing crmA variants: optimal caspase substrates are not necessarily optimal inhibitors
Details
Publication Year 1999-01-15,Volume 18,Issue #2,Page 330-338
Journal Title
EMBO JOURNAL
Publication Type
Journal Article
Abstract
To study the role of various caspases during apoptosis, we have designed a series of caspase inhibitors based on the cowpox virus cytokine response modifier A (crmA) protein. Wild-type crmA inhibits caspases 1 and 8 and thereby protects cells from apoptosis triggered by ligation of CD95 or tumour necrosis factor (TNF) receptors, but it does not protect against death mediated by other caspases. By replacing the tetrapeptide pseudosubstrate region of crmA (LVAD) with tetrapeptides that are optimal substrates for the different families of caspases, or with the four residues from the cleavage site of the baculovirus protein p35 (DQMD), we have generated a family of caspase inhibitors that show altered ability to protect against cell death. Although DEVD is the optimal substrate for caspase 3, crmA DEVD was degraded rapidly and was a weaker inhibitor than crmA DQMD, which was not degraded. Unlike wild-type crmA and crmA DEVD, crmA DQMD was able to inhibit apoptosis caused by direct activation of caspase 3 and protected lymphoid cells from death induced by radiation and dexamethasone, Significantly, the protected cells were capable of sustained growth.
Publisher
OXFORD UNIV PRESS
Keywords
INTERLEUKIN-1-BETA CONVERTING-ENZYME; C-ELEGANS CED-4; ICE/CED-3 PROTEASE; MEDIATED APOPTOSIS; AUTOIMMUNE-DISEASE; SIGNALING COMPLEX; SERPIN CRMA; DEATH; BCL-2; GENE
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Creation Date: 1999-01-15 12:00:00
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