RAB39, Member RAS Oncogene Family (RAB39)

Rab39, a novel Rab protein, is a Golgi-associated protein involved in endocytosis of HeLa cells. Full-length cDNA of Rab39 contains 1251 bp with an open reading frame (ORF) of 636 bp, which is predicted to encode a 211 aa protein.Rab39 may be a short variant of Rab34. Rab39 contains conserved motifs involved in phosphate/guanosine binding and a microbody C-terminal targeting signal. RT-PCR analysis indicates that Rab39 is mainly detected in epithelial cell lines, and Northern blot analysis shows that Rab39 is expressed ubiquitously in human tissues. Rab39 can facilitate endocytosis in HeLa cells when expressed either transiently or stably. Confocal microscopy examination of Rab39 subcellular localization suggests that Rab39 is associated with Golgi-associated organelles. Rab39 is a novel Rab GTPase involved in cellular endocytosis.