Figure 5.

Phosphorylation of SbSnRK1α restored the inhibition of StInvInh2B in the complex. The effects of the recombinant SbSnRK1α protein (the solid line shows phosphorylated SbSnRK1α and the dashed line indicates the unphosphorylated protein) on the activity of recombinant StvacINV1 protein (107 ng mL⁻¹) mixed with recombinant StInvInh2B protein (60 ng mL⁻¹) and recombinant SbSnRK1β protein (100 ng mL⁻¹) are shown. Residual invertase activity was measured at pH 4.6 and 37°C after a 1-h preincubation of the protein mixtures. ^P, The SbSnRK1α protein is phosphorylated by the upstream kinase GRIK1 in kinase reaction buffer.