Humanin peptide suppresses apoptosis by interfering with Bax activation

Speaker：趙健麟

Commentator：林秋烽老師

Time：9/17/03 15:00-16:00

Place：Room 601

Abstract：

Bax is a pro-apoptotic member of Bcl-2 family. Bax is a cytosolic protein in healthy living cells [1]. When cells suffer some death signals, it will change conformation to expose two domains to insert into mitochondria membrane and make cytochrom c release from mitochondria. The releasing of cytochrom c will activate caspases to trigger cell inducing apoptosis. Humanin（HN）, an anti-apoptotic peptide of 24 amino acids, is encoded in mammalian gemone [2]. HN peptide can interact with Bax and prevent Bax translocate to mitochondria. HN peptide can block Bax association with isolated mitochondria, and suppress cytochrome c release in vitro. Particularly, the mitochondrial genome contains an open reading frame that identical with HN peptide, and the mitochondrial version of HN can also bind and suppress Bax. Thus, the author conceives that HN originated from mitochondria and transferred to the nuclear genome, providing a mechanism for protecting these organelles from Bax.

Reference：

1.      Wolter, K. G. et al. Movement of bax from the cytosol to mitochondria during apoptosis. J. Cell Biol. 139, 1281–1292 (1997)

2.      Hashimoto, Y. et al. A rescue factor abolishing neuronal cell death by a wide spectrum of familial Alzheimer’s disease genes and Aß. Proc. Natl Acad. Sci. USA 98, 6336–6341 (2001)

3.      Guo, B. et al. Humanin peptide suppresses apoptosis by interfering with Bax activation. Nature 423, 456-461（2003）