Identification of a potential nuclear export sequence in c-IAP1. (A) (Top) Schematic representation of amino acid motifs in c-IAP1 protein (619 amino acids). Leucine-rich motifs (LRMs) that could behave as nuclear export signal (NES) are indicated (BIR indicates baculovirus IAP repeat; CARD, caspase recruitment domain). (Bottom) Amino acid sequence of regions containing a potential LRM (underlined). (B-C) The cDNA sequences encoding the 3 LRMs were fused to GFP in the pEGFP-C1 vector. These constructs were transiently transfected into HeLa cells and microscopy analyses were performed 24 hours later. Nuclei were stained with Hoechst 33342 (magnification × 500). When indicated, LMB (200 nM) was added 3 hours before analysis.