Coimmunoprecipitation of GDI1/2 with Rab proteins. HA-empty, HA-Rab10, HA-Rab29 WT, HA-Rab29 C202S+C203S (CCSS), or HA-Rab29 D63A were overexpressed in HEK293A cells and immunoprecipitated using HA-agarose beads (the bottom panel). Coimmunoprecipitation of GDI1 and GDI2 with the overexpressed HA-tagged proteins was examined by immunoblotting (the second panel from the bottom). Equal levels of the expression of GDI1/2 as well as HA-tagged proteins were shown in the top panels (input). GDI, GDP-dissociation inhibitor.