Leptomycin A, a Streptomyces metabolite, is an inhibitor of CRM1 (exportin 1) that blocks CRM1 interaction with nuclear export signals, preventing the nuclear export of a broad range of proteins. Leptomycin A suppresses HIV-1 replication. Less potent than Leptomycin B[1][2].
References:
[1]. Kudo, N., et al. Leptomycin B inhibition of signal-mediated nuclear export by direct binding to CRM1. Exp. Cell Res. 242(2), 540-547 (1998).
[2]. Wolff B, et al. Leptomycin B is an inhibitor of nuclear export: inhibition of nucleo-cytoplasmic translocation of the human immunodeficiency virus type 1 (HIV-1) Rev protein and Rev-dependent mRNA. Chem Biol. 1997 Feb;4(2):139-47.