title: Inhibition of eukaryotic translation elongation by cycloheximide and lactimidomycin.
abstract: Although the protein synthesis inhibitor cycloheximide (CHX) has been known for decades, its precise mechanism of action remains incompletely understood. The glutarimide portion of CHX is seen in a family of structurally related natural products including migrastatin, isomigrastatin and lactimidomycin (LTM). We found that LTM, isomigrastatin and analogs have a potent antiproliferative effect on tumor cell lines and selectively inhibit translation. A systematic comparative study of the effects of CHX and LTM on protein synthesis revealed both similarities and differences between the two inhibitors. Both LTM and CHX were found to block the translocation step in elongation. Footprinting experiments revealed protection of a single cytidine nucleotide (C3993) in the E-site of the 60S ribosomal subunit, thus defining a common binding pocket for the two inhibitors in the ribosome. These results shed new light on the molecular mechanism of inhibition of translation elongation by both CHX and LTM.
authors.affiliation: Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: Tilman
authors.initials: T
authors.lastname: Schneider-Poetsch
authors.forename: Jianhua
authors.initials: J
authors.lastname: Ju
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Eyler
authors.forename: Yongjun
authors.initials: Y
authors.lastname: Dang
authors.forename: Shridhar
authors.initials: S
authors.lastname: Bhat
authors.forename: William C
authors.initials: WC
authors.lastname: Merrick
authors.forename: Rachel
authors.initials: R
authors.lastname: Green
authors.forename: Ben
authors.initials: B
authors.lastname: Shen
authors.forename: Jun O
authors.initials: JO
authors.lastname: Liu