Evidence for crucial electrostatic interactions between Bcl-2 homology domains BH3 and BH4 in the anti-apoptotic Nr-13 protein

• Published in: Biochemical journal Vol. 368; no. Pt 1; pp. 213 - 221
• Main Authors: Lalle, Philippe, Aouacheria, Abdel, Dumont-Miscopein, Agnès, Jambon, Martin, Venet, Séverine, Bobichon, Hélène, Colas, Pierre, Deléage, Gilbert, Geourjon, Christophe, Gillet, Germain
• Format: Journal Article
• Language: English
• Published: England Portland Press 15-11-2002
• Subjects: Amino Acid Sequence; Animals; Apoptosis; Apoptosis - physiology; Avian Proteins; Biochemistry, Molecular Biology; Cells, Cultured; Chickens; COS Cells; Electrostatics; Life Sciences; Membrane Proteins; Membrane Proteins - chemistry; Membrane Proteins - genetics; Mice; Models, Molecular; Mutation; Protein Conformation; Protein Structure, Tertiary; Proto-Oncogene Proteins c-bcl-2; Proto-Oncogene Proteins c-bcl-2 - chemistry; Rats; Sequence Homology, Amino Acid; Static Electricity; Subcellular Fractions
• ISSN: 0264-6021; 1470-8728
• DOI: 10.1042/BJ20020836

Nr-13 is an anti-apoptotic member of the Bcl-2 family previously shown to interact with Bax. The biological significance of this interaction was explored both in yeast and vertebrate cells and revealed that Nr-13 is able to counteract the pro-apoptotic activity of Bax. The Bax-interacting domain has been identified and corresponds to alpha-helices 5 and 6 in Nr-13. Site-directed mutagenesis has revealed that the N-terminal region of Nr-13 is essential for activity and corresponds to a genuine Bcl-2 homology domain (BH4). The modelling of Nr-13, based on its similarity with other Bcl-2 family proteins and energy minimization, suggests the possibility of electrostatic interactions between the two N-terminal-conserved domains BH4 and BH3. Disruption of these interactions severely affects Nr-13 anti-apoptotic activity. Together our results suggest that electrostatic interactions between BH4 and BH3 domains play a role in the control of activity of Nr-13 and a subset of Bcl-2 family members.