Humanin (human)

Humanin was originally identified as an anti-apoptotic peptide of 24 aa encoded in a cDNA that rescued neuronal cells from apoptosis induced by presenilin mutants associated with familial Alzheimer’s disease and by amyloid-β protein [1]. Mutagenesis studies showed that the cysteine at position 8 of the humanin peptide is critical for its anti-apoptotic function [1-3]. It has now been shown that Bax (Bcl-2 associated X protein), an apoptosis-inducing protein, interacts with humanin [4]. Humanin prevents the translocation of Bax from the cytosol to mitochondria. Humanin peptides also block Bax association with isolated mitochondria, and suppress cytochrome c release in vitro.