Fig 1: Scavenging Gß? attenuates GABAB-receptor-mediated inhibition of spontaneous release(A) G-protein-coupled GABAB receptor activation inhibits neurotransmitter release by inhibiting voltage-gated Ca2+-channel-mediated Ca2+ influx and/or by Ca2+-independent mechanisms, denoted with “?.”(B) Fast synchronous evoked neurotransmitter release depends on opening of voltage-gated Ca2+ channels (VGCCs) triggered by an invading action potential at the presynaptic terminal. Local increase in Ca2+ concentration is sensed by synaptotagmin-1 (Syt1) and results in SNARE-complex-driven membrane fusion. On the other hand, spontaneous release does not require action potentials and is mediated by both Ca2+-dependent and -independent mechanisms. See the text for a detailed explanation of most recent experimental evidence on Ca2+ dependence of spontaneous release.(C) Structure of GRK2-bound Gß? (PDB: 1OMW) along with description of the experimental design. GRK2 is shown in blue, Gß is shown in pink, and G? is shown in green.(D) Immunoblot of protein samples obtained from control group (infected by lentiviral particles carrying empty backbone) and ct-GRK2 group (infected by lentiviral particles carrying ct-GRK expression vector).(E) Representative traces of miniature excitatory postsynaptic currents (mEPSCs) recorded at baseline and during 10 µM baclofen (BAC) perfusion along with quantitative analysis of % decrease in event frequency upon BAC perfusion compared with baseline (two-tailed, non-paired t test; control n = 11; ct-GRK2 n = 10).(F) Description of manipulation of ct-GRK2 to obtain myristoylated ct-GRK2 (myr ct-GRK2).(G) Immunoblot of protein samples obtained from control group (infected by lentiviral particles carrying empty backbone) and myr ct-GRK2 group (infected by lentiviral particles carrying myr ct-GRK expression vector). Compare with (E) and note the higher molecular weight of myr ct-GRK.(H) Representative traces of mEPSCs recorded at baseline and during 10 µM BAC perfusion along with quantitative analysis of event frequencies at baseline and during BAC perfusion. mEPSC frequencies at baseline and during BAC perfusion were compared using a two-tailed, paired t test, whereas mEPSC frequencies and amplitudes at baseline for control and myr ct-GRK2 were compared using a two-tailed, non-paired t test (control n = 13; myr ct-GRK2 n = 14).(I) Percent decrease in mEPSC frequency upon BAC perfusion compared with baseline (two-tailed, non-paired t test; control n = 13; myr ct-GRK2 n = 14).(J) Representative traces of miniature inhibitory postsynaptic currents (mIPSCs) recorded at baseline and during 10 µM BAC perfusion along with quantitative analysis of event frequencies at baseline and during BAC perfusion. mIPSC frequencies at baseline and during BAC perfusion were compared using a two-tailed, paired t test, whereas mIPSC frequencies and amplitudes at baseline for control and myr ct-GRK2 were compared using a two-tailed, non-paired t test (control n = 11; myr ct-GRK2 n = 11).(K) Percent decrease in mIPSC frequency upon BAC perfusion compared with baseline (two-tailed, non-paired t test; control n = 11; myr ct-GRK2 n = 11).(L) Quantitative analyses of mEPSC and mIPSC frequencies at baseline and during GABAB-receptor antagonist saclofen (200 µM) perfusion (two-tailed, paired t test; mEPSC frequency n = 9; mIPSC frequency n = 8).All panels: significance levels are stated as follows: *p < 0.05; **p < 0.01; ***p < 0.001; and ****p < 0.0001. ns denotes non-significance.
Supplier Page from Abcam for Anti-GRK2 antibody - C-terminal