Lactacystin

Lactacystin is a potent and selective irreversible proteasome inhibitor and cathepsin A inhibitor. Lactacystin is a microbial metabolite isolated from Streptomyces first characterized by its ability to induce differentiation and inhibit cell cycle progression in several tumor cell lines. Lactacystin irreversibly alkylates subunit X of the 20S proteasome. The concomitant inhibition of proteasome peptidase activity results in the accumulation of a variety of ubiquitinated proteins. Thus, the effects of this substance are pleiotropic and depend substantially on the expression pattern of signaling proteins within the treated cell. Shown to inhibit cell proliferation and to induce neurite outgrowth in murine neuroblastoma cell lines such as Neuro 2a.