Figure 5.
Transient stimulation of GαqGTP–PLCβ induced PIP2 hydrolysis by Gβγ is Gγ-type dependent.A, HeLa cells expressing GRPR and Venus–PH with either Gγ3 or Gγ9 exhibited no significant difference in the rate or extent of either PIP2 hydrolysis (graph) or its subsequent recovery (response curves and whisker box plot) when stimulated with 1 μM bombesin. B, synergistic activation of PLCβ in HeLa cells expressing either Gγ3 or Gγ9. Response curves show that while cell expressing both Gγ types showed similar PIP2 hydrolysis responses, Gγ9 cells showed a significantly faster and greater PIP2 recovery. Whisker box plot exhibits the different rates (Hill slopes) of PIP2 hydrolysis adaptation. The scale bar represents 10 mm. Average curves plotted using n ≥10 cells from ≥3 independent experiments. The error bars represent the SEM. PIP2, phosphatidylinositol 4,5-bisphosphate; PLCβ, phospholipase C β.