PRAF3 (alias: GTRAP3-18, ARL6IP5, HSPC127, DERP11, JWA, addicsin, hp22, jmx, Yip6b), belonging to prenylated Rab acceptor 1 (PRA1) superfamily, is highly conserved amongst vertebrates. PRAF3 plays crucial roles in membrane traffic as a GDI displacement factor via protein interaction with a variety of Rab proteins, as well as in the modulation of antioxidant glutathione through its interaction with the amino acid transporter EAAC1.  It is known that the overexpression of PRAF3 induces the toxicity of the host cell, however, the factors capable of reducing the cytotoxicity remained unknown.  My findings demonstrate that Rab1a can protect from the cytotoxicity of PRAF3-overexpressed cells.  Cytoprotective effects of Rab1a protein could further suggest that PRAF3 and Rab1a are closely related to each other physiologically. I hope that the findings will contribute to the future research on membrane trafficking and neurodegenerative diseases.