Rattin, a novel rat gene, encodes a peptide homologous to Humanin, a secreted peptide that specifically protects against neuronal cell death induced by beta-amyloid peptide (Ab) or by mutations causing early-onset familial Alzheimers disease. Rattin is the prototype of a novel class of peptides, phylogenetically related to Humanin, endowed with protective activity not only against Ab but also toward excitotoxic neuronal death. The rat gene, Rattin, encodes a peptide of 38 residues (15 residues longer than Humanin) showing 73% identity in the conserved region to Humanin.
