FIG. 5.

Mitochondrial or nuclear targeting of HA epitope-tagged DNA ligase III minigene products. Mammalian expression vectors harbored HA-tagged DNA ligase III minigenes in which either M1 (pLIG-FL-1) or M2 (pLIG-FL-2) was inactivated. Filled arrows, cytomegalovirus promoter from expression vector; white boxes, DNA ligase III cDNA; hatched boxes, simian virus 40 polyadenylation signal; shaded boxes, ATG codons M1 and M2 (the absence of these boxes indicates that the relevant ATG site has been inactivated). Expression constructs harboring HA-tagged DNA ligase III proteins were used to transiently transfect Cos-1 cells, and subcellular localization was visualized by immunocytochemistry using fluorescein-labeled anti-HA monoclonal antibody (confocal images of cells transfected with pLIG-FL-1 or pLIG-FL-2 are displayed beneath the expression constructs).