1. Volume 16, Issue 3, Pages 579-585 (March 1996)
G Protein–Coupled Receptor Kinase Mediates Desensitization of Norepinephrine- Induced Ca2+ Channel Inhibition 
Marı́a Diversé-Pierluissi, James Inglese, Robert H Stoffel, Robert J Lefkowitz, Kathleen Dunlap 
Neuron 
Volume 16, Issue 3, Pages (March 1996)
DOI: /S (00)80077-X

2. Figure 1 NE-Induced Desensitization of Ca2+ Current in Sensory Neurons
Peak (A and B) or normalized (C) Ca2+ currents are plotted as a function of time before and during (horizontal bar) application of NE. In (A), a brief application period of 40 s is followed by washout of transmitter and full recovery of the current (open circles, n = 3); closed circles represent the average time course for Ca2+ current rundown in 3 cells measured from the same culture dish. (B) shows plotted data from a single cell during prolonged application of 100 μM NE. (C) shows plotted averaged, Ca2+ currents normalized to maximum control current (n = 3) before and during application of 100 μM (open circles) or 10 μM (Δ) NE. Standard errors of the mean fall within the symbol boundaries for most data points (range ± 0.03–0.07).
Neuron  , DOI: ( /S (00)80077-X)

3. Figure 2 Two Modulatory Components Desensitize at Different Rates
Kinetic slowing and steady-state inhibition were separated according to the methods described in Experimental Procedures. The average percentage inhibition (n = 3) is plotted as a function of time for each component. Time zero marks the beginning of NE application; the plotted data begin at the time at which maximal inhibition was reached. Standard errors of the mean fall within the symbol boundaries for most data points (range ± 0.6–4%). Inset; superimposed currents demonstrating the isochronal measurement of kinetic slowing (ks) and steady-state inhibition (ssi).
Neuron  , DOI: ( /S (00)80077-X)

4. Figure 3 GRK3 Enhances Desensitization of the NE Response
The fraction of NE-induced kinetic slowing (A) and steady-state inhibition (B) are plotted as a function of time for control (circles), GRK3-injected (triangles), and GRK2-injected (squares) cells. Time zero marks the time at which maximal inhibition was achieved. Data points represent the average of three cells. Standard errors of the mean fall within the symbol boundaries for most data points (range ± 0–0.05).
Neuron  , DOI: ( /S (00)80077-X)

5. Figure 4
Activity of GRK2 and GRK3 on β2AR and Western Blot Analysis of Protein from Dorsal Root Ganglia
(A) Kinase activities of GRK2 and GRK3 on β2AR were assessed in the absence and presence of βγ (28 μg/ml), as marked. The graph is representative of two individual experiments, each performed in triplicate. Data are plotted as the mean ± standard deviation. (B) Western blot of recombinant GRK2 (10 ng, rGRK2), GRK3 (10 ng, rGRK3), and dorsal root ganglia (100 μg, DRG) probed with antiserum that recognizes both GRK2 and GRK3. Data are representative of five separate experiments on two separate preparations of dorsal root ganglia.
Neuron  , DOI: ( /S (00)80077-X)

6. Figure 5 Peptide G Retards Desensitization of the NE Response
The fraction of maximal inhibition is plotted as a function of time for NE-induced kinetic slowing (closed circles) and steady-state inhibition (open circles). Transmitter (100 μM) was applied for the period marked by the horizontal bar (NE) and then washed out of the bath during the period marked by the dashed line (wash). Data points represent the average of three cells. Standard errors of the mean fall within the symbol boundaries for most data points (range ± 0–0.08).
Neuron  , DOI: ( /S (00)80077-X)