Figure 3.

(A) Binding of His-tagged Arl1 Q71L or untagged Rab9 to GST-Golgin-245 (123 residues) or GST-GCC185 (110 residues) C termini. Reactions contained 30 pmol of Rab9 or 11 pmol of Arl1 Q71L. Golgin-245 bound 9647 cpm of Arl1 protein; GCC185 bound 6334 cpm of Rab9 protein. (B) Binding of GST-GCC185 or GST-GCC185 Y1618A C-terminal fragments to Rab9 (light bars) or Rab5 (dark bars). Reactions contained 140 pmol of Rab9 or Rab5. Experiments were carried out using [³⁵S]GTPγS-preloaded Rab GTPases. Rab9 binding represents ∼15,000 cpm. (C) Cellular depletion of Rab9 does not influence GCC185 localization. Cells were treated with Rab9 siRNA for 72 h; the localization of endogenous GCC185 and Rab9 were then monitored using rabbit anti-GCC185 and mouse anti-Rab9 IgG. Bar, 20 μm.