Formation of SGs by overexpression of CERKL requires the nuclear import/export of the protein.

A) COS-7 cells overexpressing CERKL-HA were mock-treated (upper row) or treated for 2 h with 40 nM leptomycin B (LeptB), 1 µg/mL actinomycin D (ActD) or 100 µg/mL alpha-amanitin (α-Aman). Then, the localizations of CERKL (HA) and PABP (marker of SGs) were investigated by immunofluorescence. B) COS-7 cells overexpressing the CERKL-C125W mutant were mock-treated or treated with 500 µM SA for 30 min and the localizations of the mutant CERKL (CERKL C125W-HA) and PABP (upper panels) or eIF4E (lower panels) were investigated by immunofluorescence. Images at higher magnification of the rectangles are shown on the right. All bars: 10 µm.