Effects of Dissociation Rate on Calcium Enhancement of Dopamine-Induced PKAc Elevation and PP1 Suppression

<div><p>In all panels, the response is the maximal ratio of PKAc to PP1. All panels show the effect of dissociation rate on the response to dopamine alone (green dashed line, stars), calcium alone (blue dashed line, circles), and paired dopamine and calcium (red dashed line, squares).</p><p>(A) Response is independent of rate of calcium-dependent AC5 inhibition.</p><p>(B) Response is independent of rate of Ca₄CaM binding to PDE1.</p><p>(C) Response is slightly sensitive to the rate of calcium binding to PP2A: for very fast (*100) calcium dissociation rate, the enhancing role of calcium decreases because the activation of PP2A is too brief to dephosphorylate significant amounts of phosphoThr75 following brief calcium inputs.</p>