Yeast Ypt11 is targeted to recycling endosomes in mammalian cells

Background information. In yeast, Ypt11 or Ypt32 along with the highly homologous Ypt8 or Ypt31 has been reported to be an essential component of intra-Golgi trafficking and has been implicated in the budding of vesicles from the most distal Golgi compartment. Results and conclusions. In the present study, we show that, in human cells, after heterologous expression of GFP-Ypt11 (where GFP stands for green fluorescent protein), the protein is targeted to transferrin-positive recycling endosomes. This compartment has been shown to form extensive tubular networks on applying the drug Brefeldin A. We also show, by confocal fluorescent microscopy, that these networks also contain Rab11 in cells expressing CFP-Rab11a (where CFP stands for cyan fluorescent protein) fusion protein and that these structures are identical with those targeted by GFP-Ypt11.