Apoptosis is a natural form of cell death involved in many physiological changes in the cell. Defects in the process of apoptosis can lead to serious diseases. During some apoptotic pathways, proteins apoptosis-inducing factor (AIF) and endonuclease G (EndoG) are released from the mitochondria and they translocate into the cell nuclei, where they probably participate in chromatin degradation together with other nuclear proteins. Exact mechanism of EndoG activity in cell nucleus is still unknown. Some interacting partners like flap endonuclease 1, DNase I, and exonuclease III were already suggested, but also other interacting partners were proposed. We conducted a living-cell confocal fluorescence microscopy followed by an image analysis of fluorescence resonance energy transfer to analyze the possibility of protein interactions of EndoG with histone H2B and human DNA topoisomerase II alpha (TOPO2a). Our results show that EndoG interacts with both these proteins during apoptotic cell death. Therefore, we can conclude that EndoG and TOPO2a may actively participate in apoptotic chromatin degradation. The possible existence of a degradation complex consisting of EndoG and TOPO2a and possibly other proteins like AIF and cyclophilin A have yet to be investigated.

• MeSH
• Antigens, Neoplasm chemistry   genetics   metabolism   MeSH
• Apoptosis * MeSH
• Cell Nucleus enzymology   pathology   MeSH
• Time Factors MeSH
• DNA-Binding Proteins chemistry   genetics   metabolism   MeSH
• DNA Topoisomerases, Type II chemistry   genetics   metabolism   MeSH
• Endodeoxyribonucleases chemistry   genetics   metabolism   MeSH
• HeLa Cells MeSH
• Histones chemistry   genetics   metabolism   MeSH
• Protein Interaction Domains and Motifs MeSH
• Microscopy, Confocal MeSH
• Protein Conformation MeSH
• Humans MeSH
• Protein Interaction Mapping MeSH
• Models, Molecular MeSH
• Recombinant Fusion Proteins metabolism   MeSH
• Chromatin Assembly and Disassembly * MeSH
• Fluorescence Resonance Energy Transfer MeSH
• Transfection MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Antigens, Neoplasm MeSH
• DNA-Binding Proteins MeSH
• DNA Topoisomerases, Type II MeSH
• Endodeoxyribonucleases MeSH
• endonuclease G MeSH Browser
• Histones MeSH
• Recombinant Fusion Proteins MeSH