TABLE 2.
Specific activities for GST-ELMOD proteins against six different ARF family GTPases
Specific activity values (nmol min−1 mg−1) for GST fusion proteins of the human ELMODs against each of the indicated ARF family members. Specific activities were determined as described under “Experimental Procedures.” GTPases (1 μm) were pre-loaded with [γ-32P]GTP as described under “Experimental Procedures” and diluted into the assay to begin the reaction. Specific activities were determined as described in the legend to Table I, using titration curves that included at least 8 concentrations of each ELMO domain protein between 0 and 4 μm. Variations within duplicates and between experiments were less than 15%.
| ARL2 | ARF1 | ARF6 | ARL1 | ARL3 | ARL13B | |
|---|---|---|---|---|---|---|
| ELMOD1 | 0.76 | 0.06 | 93 | 10 | 0.001 | NAa |
| ELMOD2 | 30.0 | 255 | 422 | 1107 | 67 | NA |
| ELMOD3 | 0.03 | 0.02 | NA | 0.07 | 0.02 | NA |
| ELMO1 | NA | NA | NA | NA | NA | NA |
a NA, not active, indicates no detectable difference between the ELMOD sample and buffer control in the GAP assay.