FIG. 5.

Pak1-dependent activation of Snf1 kinase activity. (A) Increasing concentrations of Snf1 kinase complexes (fractions 17 and 19) were incubated with [γ-³²P]ATP and recombinant GST-Mig1 protein. Incorporation of radioactivity into the GST-Mig1 protein (and its proteolytic fragments) was detected by autoradiography. Snf1 kinase had been purified from PAK1 (lanes 1 to 3 and 7 to 9) and pak1Δ (lanes 4 to 6 and 10 to 12) mutant cells. (B) Increasing concentrations of Snf1 kinase purified from pak1Δ mutant cells (fraction 17) were incubated with [γ-³²P]ATP, GST-Mig1 protein, and either buffer (lanes 1 to 3) or purified Pak1 kinase (lanes 4 to 6). Snf1 kinase was omitted from one reaction mixture (lane 7).