Figure 2.

SNAK phosphorylates SNAP-23 in vitro. (A) GST-SNAK was incubated with immobilized GST, GST-syntaxin 4, or GST-SNAP-23 in the presence of [γ-³²P]ATP at 30°C for 10 min. The reaction was terminated by extensive washing, and in vitro phosphorylation reactions were analyzed by SDS-PAGE and autoradiography. The relative mass (M_r) of ¹⁴C-labeled molecular weight markers is indicated. (B) His₆-SNAP-23 (1.5 μg) was incubated with the indicated amount of GST-SNAK in the presence of [γ-³²P]ATP at 30°C for 30 min. The reaction products were analyzed by SDS-PAGE and autoradiography.