KOPS - Das Institutionelle Repositorium der Universität Konstanz

Influence of caspase-binding ability of the X-linked Inhibitor of Apoptosis Protein (XIAP) on serine protease inhibitor-sensitive apoptosis

Influence of caspase-binding ability of the X-linked Inhibitor of Apoptosis Protein (XIAP) on serine protease inhibitor-sensitive apoptosis

Zitieren

Dateien zu dieser Ressource

Prüfsumme: MD5:710294bfc263b91bffb3d186b2575834

WALLISER, Michael, 2005. Influence of caspase-binding ability of the X-linked Inhibitor of Apoptosis Protein (XIAP) on serine protease inhibitor-sensitive apoptosis

@phdthesis{Walliser2005Influ-6579, title={Influence of caspase-binding ability of the X-linked Inhibitor of Apoptosis Protein (XIAP) on serine protease inhibitor-sensitive apoptosis}, year={2005}, author={Walliser, Michael}, address={Konstanz}, school={Universität Konstanz} }

Einfluss der Caspasebindefähigkeit von XIAP auf eine Serinproteaseinhibitor-empfindliche Apoptose Walliser, Michael Cell death independent of caspase activity and sensitive to serine protease inhibitors has been described for many different cellular systems. However, this type of cell death has not been demonstrated for the cervix carcinoma derived HeLa cell line so far.<br />In the presented study, the ability of HeLa cells to undergo cell death after caspase arrest was investigated. For this purpose, concentration-dependent caspase inhibitor studies were performed together with analyses of serine protease inhibitors in cell death lacking caspase activity. As a result, induction of apoptosis with TNFα revealed a serine protease inhibitor-sensitive cell death after caspase arrest. Since over-expression of XIAP protects HeLa cells, different XIAP mutants were employed to investigate this serine protease inhibitor-sensitive cell death. Expression of a mutant abolished to bind and inhibit caspases completely failed to protect HeLa cells from TNFα induced apoptosis. This result demonstrates that the caspase binding sites of XIAP are decisive for the inhibitory abilities. To distinguish between caspase-dependent and other functions of XIAP, a mutant lacking the C-terminal RING domain was assayed. This mutant significantly protected cells but protection was accompanied by a dramatic decrease in potency. Since the E3 ubiquitin protein ligase is localized within the RING domain, a XIAP with abolished ligase activity was assayed to characterize this ineffectiveness. This defect caused an ineffectiveness of protection comparable to the complete removal of the RING domain. Finally, experiments combining the caspase inhibitor experiments with the expression of XIAP mutants did not revealed any caspase-independent effects of the protection by XIAP. These results show that the caspase-binding abilities of XIAP are essential for protection of HeLa cells from caspase independent and dependent cell death.<br />To investigate whether caspase-8 was able to induce this serine protease inhibitor-sensitive cell death after caspase arrest, experiments were performed, which short-circuited the receptor pathway with an active caspase-8. Over-expression of caspase-8 caused a cell death that was independent of caspase-3-like activity and hardly preventable by XIAP. However, it was sensitive towards serine protease inhibitors after caspase arrest indicating that caspase-8 is able to induce this described cell death in HeLa cells. 2005 Influence of caspase-binding ability of the X-linked Inhibitor of Apoptosis Protein (XIAP) on serine protease inhibitor-sensitive apoptosis Walliser, Michael application/pdf eng deposit-license 2011-03-24T17:27:33Z 2011-03-24T17:27:33Z

Dateiabrufe seit 01.10.2014 (Informationen über die Zugriffsstatistik)

Diss_Walliser.pdf 169

Das Dokument erscheint in:

KOPS Suche


Stöbern

Mein Benutzerkonto