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Updated: Aug 15, 2026

Examining BCL-2 Family Function with Large Unilamellar Vesicles
Published on: October 5, 2012
Cytoprotective membrane-permeable peptides designed from the Bax-binding domain of Ku70
Motoshi Sawada1, Paulette Hayes, Shigemi Matsuyama
1Blood Research Institute, The Blood Center of South Eastern Wisconsin and Department of Biochemistry, Medical College of Wisconsin 8727 Watertown Plank Rd, Milwaukee WI 53226, USA.
Abstract:
Bax is a pro-apoptotic member of Bcl-2 family proteins and is central to mitochondria-dependent apoptosis. Bax resides in the cytosol as a quiescent protein and translocates into mitochondria after apoptotic stimuli. Ku70 is a 70K subunit of the Ku complex, which has an important role in DNA double-strand break (DSB) repair in the nucleus. In another article in this issue, we reported that Ku70 interacts with pro-apoptotic protein Bax in the cytosol and prevents its mitochondrial translocation, suggesting that Ku70 suppresses Bax-mediated apoptosis. Here, we describe the development of a new membrane-permeable peptide, Bax-inhibiting peptide (BIP) that inhibits Bax-mediated apoptosis, on the basis of the previous finding that showed an interaction between Ku70 and Bax. BIP is comprised of five amino acids designed from the Bax-binding domain of Ku70, and suppresses the mitochondrial translocation of Bax. BIP inhibited Bax-mediated apoptosis induced by staurosporine, UVC irradiation and anti-cancer drugs in several types of cells. BIP may provide valuable information in the development of therapeutics that control apoptosis-related diseases.
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