Leptomycin A (CAS 87081-36-5)

Leptomycin A, identified by the CAS number 87081-36-5, is a small molecule compound originally isolated from the bacterium Streptomyces atroolivaceus. It is a member of the leptomycin class of antibiotics, renowned for their distinct and potent biological activities. Leptomycin A is particularly notable for its mechanism of action as a specific inhibitor of the nuclear export protein CRM1 (also known as exportin 1). CRM1 is essential for the transport of various proteins from the nucleus to the cytoplasm, including proteins involved in cell cycle regulation and stress responses. By binding to CRM1, leptomycin A effectively blocks the nuclear export signal (NES), which is necessary for the translocation of NES-containing proteins out of the nucleus. This inhibition leads to the accumulation of these proteins in the nucleus, affecting numerous cellular functions and regulatory mechanisms. In research contexts, leptomycin A has been extensively used as a tool to study nuclear-cytoplasmic transport and to explain the roles of nuclear retention in controlling protein function and signaling pathways. The ability of leptomycin A to modulate protein localization provides valuable insights into the fundamental processes of cellular regulation and has been instrumental in probing the complex dynamics of nuclear transport and its implications for cell physiology.