Conversion of Bfl-1, an anti-apoptotic Bcl-2 family protein, to a potent pro-apoptotic protein by fusion with green fluorescent protein (GFP)

• Published in: FEBS letters 2003-09, Vol.551 (1), p.29-36
• Main Authors: Ko, Jae-Kyun, Choi, Kyoung-Han, Kim, Hee-Jung, Choi, Hye-Young, Yeo, Dong-Jun, Park, Sue-O, Yang, Wan Seok, Kim, Yong-Nyun, Kim, Chul-Woo
• Format: Article
• Language: English
• Subjects: Apoptosis; Bcl-2 family; bcl-X Protein; Bfl-1; BH, Bcl-2 homology; Caspases - physiology; Cell Line; Cytochrome c Group - metabolism; GFP, green fluorescence protein; Green fluorescent protein; Green Fluorescent Proteins; Humans; Luminescent Proteins - genetics; Minor Histocompatibility Antigens; Mitochondria - chemistry; Mitochondria - metabolism; Protein Structure, Tertiary; Proto-Oncogene Proteins c-bcl-2 - chemistry; Proto-Oncogene Proteins c-bcl-2 - genetics; Proto-Oncogene Proteins c-bcl-2 - metabolism; Recombinant Fusion Proteins - analysis; Recombinant Fusion Proteins - antagonists & inhibitors; Recombinant Fusion Proteins - metabolism; TM, transmembrane; z-VAD-fmk, carbobenzoxy-Val-Ala-Asp-fluoromethyl ketone
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/S0014-5793(03)00872-X

Human Bfl-1 is an anti-apoptotic Bcl-2 family member. Here, we found that Bfl-1 was converted into a potent death-promoting protein by green fluorescent protein (GFP) fusion with its N-terminus. The transient expression of GFP-Bfl-1 induced cytochrome c release and triggered apoptosis in 293T cells, which depended on the mitochondrial localization of GFP-Bfl-1. Apoptosis induced by GFP-Bfl-1 was significantly blocked by the pan-caspase inhibitor carbobenzoxy-Val-Ala-Asp-fluoromethyl ketone, but was not blocked by either Bcl-xL or Bfl-1. Our findings provide a useful model for understanding the structural basis of Bcl-2 family proteins that act in an opposite way despite sharing structural similarity between anti-apoptotic and pro-apoptotic proteins.