Subcellular localization of SRPUL-CF proteins. FL5.12 cells expressing SRPUL-CF were immunostained with an -FLAG MoAb (M2). Simultaneous staining with DAPI permitted visualization of cell nuclei (panels A′, B′, C′, D′). The FL5.12 cells were stably transfected with a zinc-regulated pMT vector containing SRPUL-CF (panels A, A′, B, B′) or the empty vector (panels C, C′, D, D′). Cells were grown in the absence of zinc (panels A, A′, C, C′) or 16 hours after its addition to the medium (100 μmol/L; panels B, B′, D, D′).