Journal Article

Modulation of the CD95-Induced Apoptosis: The Role of CD95 N-Glycosylation

Kubarenko, Andriy V., Schwartz-Albiez, Reinhard, Pappa, Alexander, Weber, Alexander N. R., Weber, Claudia E. M., Krammer, Peter H., Lavrik, Inna N., Shatnyeva, Olga M.

2011

Overview

Protein modifications of death receptor pathways play a central role in the regulation of apoptosis. It has been demonstrated that O-glycosylation of TRAIL-receptor (R) is essential for sensitivity and resistance towards TRAIL-mediated apoptosis. In this study we ask whether and how glycosylation of CD95 (Fas/APO-1), another death receptor, influences DISC formation and procaspase-8 activation at the CD95 DISC and thereby the onset of apoptosis. We concentrated on N-glycostructure since O-glycosylation of CD95 was not found. We applied different approaches to analyze the role of CD95 N-glycosylation on the signal transduction: in silico modeling of CD95 DISC, generation of CD95 glycosylation mutants (at N136 and N118), modulation of N-glycosylation by deoxymannojirimycin (DMM) and sialidase from Vibrio cholerae (VCN). We demonstrate that N-deglycosylation of CD95 does not block DISC formation and results only in the reduction of the procaspase-8 activation at the DISC. These findings are important for the better understanding of CD95 apoptosis regulation and reveal differences between apoptotic signaling pathways of the TRAIL and CD95 systems.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Activation / Analysis / APO-1 protein / Apoptosis / Bacteria / Biology / Blotting, Western / Cancer / Caspase 8 - metabolism / CD95 antigen / Cells, Cultured / Cellular signal transduction / Cholera toxin / Computational Biology / Cytochrome / Death Domain Receptor Signaling Adaptor Proteins / Deglycosylation / Enzyme-Linked Immunosorbent Assay / Fas antigen / fas Receptor - chemistry / fas Receptor - genetics / fas Receptor - metabolism / Flow Cytometry / Glycosylation / Humans / Immunoprecipitation / Ligands / Lymphocytes - cytology / Lymphocytes - metabolism / Medical research / Modulation / Mutagenesis / Mutants / Mutation - genetics / Protein Conformation / Proteins / Signal Transduction / Signaling / TNF-Related Apoptosis-Inducing Ligand - metabolism / TRAIL protein / Tumor necrosis factor-TNF / Waterborne diseases