Addition of ER retrieval sequences to an apicoplast-targeted protein leads to reduced delivery to the apicoplast. A and C) Live-cell imaging of parasites expressing the apicoplast leader sequence of ACP (BTS) fused to GFP (top panel), GFP_KDEL (middle panel) and GFP_SDEL (both KDEL and SDEL are ER retention sequences; lower panel) under control of either the PfCRT (PCRT) or PfACP (PACP) promoter. B and D) Immunofluorescence assay of parasites expressing the apicoplast leader BTS fused to GFP (i, ii), GFP_KDEL (iii, iv) and GFP_SDEL (v, vi) as described above with anti-PfACP (apicoplast marker) and anti-PfERC (ER marker) antibodies. Scale bar: 3 μm (all).

Heiny SR, Pautz S, Recker M, Przyborski JM. Protein Traffic to the Plasmodium falciparum Apicoplast: Evidence for a Sorting Branch Point at the Golgi. Traffic. 2014 15(12):1290-304