Human RAB24, interestingly and predominantly distributed in the nuclei of COS-7 cells, is colocalized with cyclophilin A and GABARAP.

As an atypical member of the Rab family, Rab24 has several attributes distinguishing this protein from the other members. Based on the yeast two-hybrid system, interaction between human RAB24 and two proteins, cyclophilin A (CyP-A) and gamma-aminobutyric acid type A receptor-associated protein (GABARAP), was detected and identified in COS-7 cells. Interestingly, RAB24 is predominantly localized in the nuclei of COS-7 cells, which is different from previous reports using other cell lines. RAB24 (D123I) can trigger the accumulation of intracellular inclusions, with small quantities of intranuclear inclusions in some cells. The GTPase activity of RAB24 and its two mutants was detected.