Figure 12.

Effects of Kinase Inhibitors on State Transitions and PII Phosphorylation.

S. elongatus (A) to (C) and Synechocystis (D) to (F) cells were incubated in the absence and presence of kinase inhibitors for 90 min in darkness. Then the cells (Chl concentration 2.5 μg/mL) were successively illuminated with blue light (85 µM photons m⁻² s⁻¹) and orange light (40 µM photons m⁻² s⁻¹), and the fluorescence changes were followed using a PAM fluorometer.

(A) and (D) Control cells containing DMSO (0.1% v/v).

(B) and (E) Cells treated with stausporine (21 µM).

(C) and (F) Cells treated with K252a (1.07 µM). Saturating pulses (400 ms × 1200 µM photons m⁻² s⁻¹) were applied every 60 s.

(G) Gel electrophoresis containing Phos-tag to detect phosphorylated proteins and immunoblot using an anti-PII protein. (1) BG11 medium; (2) nitrogen-depleted BG11 medium; (3) nitrogen-depleted BG11 medium supplemented with K252a (1.07 µM); (4) nitrogen-depleted BG11 medium supplemented with staurosporine (21 µm).