Chen IS , Furutani K , Inanobe A , Kurachi Y .

	Figure 1. Effects of RSG4 on ACh- and pilocarpine-evoked KG currentsA, 100 μm pilocarpine-evoked KG currents (red) relative to 1 μm ACh-evoked KG currents (black) in the same rat atrial myocyte. Whole-cell currents were recorded with a voltage pulse protocol as showed below the current traces and basal currents were subtracted. Arrowheads indicate the zero current level. Pilocarpine (100 μm)-evoked currents were blocked in the presence of 0.7 μm atropine (B) or 0.1 μm tertiapin-Q (C) in atrial myocytes. Agonist-evoked currents were recorded in the same oocyte expressing M2Rs and the Kir3.1/Kir3.4 heteromultimer with (D) and without (E) RGS4 at −100 mV.
	Figure 2. Concentration–response curve of pilocarpine and AChCurrents were recorded in the presence of pilocarpine (0.1–100 μm) and ACh (0.001–10 μm) with a holding potential of −60 mV in oocytes with (A) and without (C) expression of RGS4. The bars above each trace indicate the periods and concentrations of application of ACh or pilocarpine. Dashed lines indicate the zero current level and arrowheads indicate the basal current level. Concentration–response curves of pilocarpine and ACh in oocytes with (B) or without (D) expression of RGS4. The average maximal response of ACh-evoked KG currents was set as 100%. The vertical axis indicates the relative percentages of response that were induced by each concentration of agonists. Data show the means ± SEM, n = 6 at each concentration in both with and without RGS4 groups. All symbols have attached error bars, but some of them are smaller than the symbol.
	Figure 3. Voltage-dependence of relative response of pilocarpine to AChACh (1 μm, a) and pilocarpine (100 μm, b)-evoked KG currents in oocytes with (A) and without (B) expression of RGS4. Whole-cell currents were recorded with a step protocol as showed above the current traces and basal currents were subtracted. Arrowheads indicate the zero current level. C, the pilocarpine (100 μm)-evoked KG currents as a percentage of ACh (1 μm)-evoked KG currents at each membrane potential were calculated from steady state. Filled circles indicate the oocytes expressing RGS4; open circles indicate absence of RGS. The graph shows the means ± SEM, n = 6 for each condition.
	Figure 4. Requirements of RGS4 domain for partial agonism of the M2R-activated KG currentsA, ACh (1 μm)-evoked KG currents (black) and pilocarpine (100 μm)-evoked KG currents (red) in oocytes expressing wild-type RGS4 (a), without RGS4 expression (b) and expressing various RGS4 mutants (c–h) at –60 mV. B, formations of truncated mutants of RGS4 and a point mutation in RGS domain. Black portions represent the region of RGS domain. C, the response of pilocarpine-evoked KG currents relative to ACh-evoked KG currents was calculated from steady state at −60 mV. The bar graph shows the means ± SEM, n = 6–9. The filled bars indicate that the intact RGS domain is included in the mutants; the open bars indicate absence of the intact RGS domain and a significant difference (P < 0.05) from the wild-type RGS4 group.
	Figure 5. Effects of a palmitoylation inhibitor 2–BP on agonist-evoked KG currentsACh (1 μm)-evoked KG currents were recorded in RGS4-expressing oocytes in vehicle (contained ≤0.1% ethanol) (A) or pretreatment with 2–BP (100 μm) for ≥2 h (B) with a continuous test pulse as showed on the right side of current traces. The interval of each pulse is 3 s. Relative KG currents of pilocarpine (100 μm) to ACh (1 μm) were recorded in the same oocyte at −60 mV in the presence of vehicle (C) or 2–BP (D). Basal currents were subtracted.
	Figure 6. Suppression of dopamine-evoked KG currents by pilocarpine via RGS4 and M2RAgonist-evoked KG currents were recorded in oocytes expressing D2R and M2R (injected cRNA ratio of D2R to M2R = 100, D/M = 100) with (A) or without (B) RGS4 by a continuous test pulse as shown above the current traces. The bars above each trace indicate the application of dopamine, pilocarpine and K+ channel blocker Ba2+. C, the current recorded in an oocyte that did not express M2R. D, the current recorded in an oocyte that did not express D2R. E, the ratio of dopamine-evoked currents in the presence of pilocarpine (100 μm) to dopamine-evoked currents in the absence of pilcarpine at −60 mV. Basal and pilocarpine-evoked currents were subtracted. D/M = 100 indicates the high M2R-expressing group and D/M = 1000 indicates the low M2R-expressing group (injected cRNA ratio of D2R to M2R = 1000). Data show the mean ± SEM, n = 6. * indicates a significant difference (P < 0.05).

Abramow-Newerly, RGS proteins have a signalling complex: interactions between RGS proteins and GPCRs, effectors, and auxiliary proteins. 2006, Pubmed

Abramow-Newerly, RGS proteins have a signalling complex: interactions between RGS proteins and GPCRs, effectors, and auxiliary proteins. 2006, Pubmed
Bastin, Amino-terminal cysteine residues differentially influence RGS4 protein plasma membrane targeting, intracellular trafficking, and function. 2012, Pubmed
Ben-Chaim, Movement of 'gating charge' is coupled to ligand binding in a G-protein-coupled receptor. 2006, Pubmed , Xenbase
Blazer, A nanomolar-potency small molecule inhibitor of regulator of G-protein signaling proteins. 2011, Pubmed
Bymaster, Arachidonic acid release in cell lines transfected with muscarinic receptors: a simple functional assay to determine response of agonists. 1999, Pubmed
Cifelli, RGS4 regulates parasympathetic signaling and heart rate control in the sinoatrial node. 2008, Pubmed
Clark, Endogenous RGS protein action modulates mu-opioid signaling through Galphao. Effects on adenylyl cyclase, extracellular signal-regulated kinases, and intracellular calcium pathways. 2003, Pubmed
Croft, A physiologically required G protein-coupled receptor (GPCR)-regulator of G protein signaling (RGS) interaction that compartmentalizes RGS activity. 2013, Pubmed
Doupnik, RGS proteins reconstitute the rapid gating kinetics of gbetagamma-activated inwardly rectifying K+ channels. 1997, Pubmed , Xenbase
Fujita, A regulator of G protein signalling (RGS) protein confers agonist-dependent relaxation gating to a G protein-gated K+ channel. 2000, Pubmed , Xenbase
Hepler, Emerging roles for RGS proteins in cell signalling. 1999, Pubmed
Hibino, Inwardly rectifying potassium channels: their structure, function, and physiological roles. 2010, Pubmed
Hollinger, Cellular regulation of RGS proteins: modulators and integrators of G protein signaling. 2002, Pubmed
Inanobe, Interaction between the RGS domain of RGS4 with G protein alpha subunits mediates the voltage-dependent relaxation of the G protein-gated potassium channel. 2001, Pubmed , Xenbase
Ishii, Ca(2+) elevation evoked by membrane depolarization regulates G protein cycle via RGS proteins in the heart. 2001, Pubmed
Jaén, RGS3 and RGS4 differentially associate with G protein-coupled receptor-Kir3 channel signaling complexes revealing two modes of RGS modulation. Precoupling and collision coupling. 2006, Pubmed , Xenbase
Jasinski, Human pharmacology and abuse potential of the analgesic buprenorphine: a potential agent for treating narcotic addiction. 1978, Pubmed
Kawai, Effect of three types of mixed anesthetic agents alternate to ketamine in mice. 2011, Pubmed
Krapivinsky, The G-protein-gated atrial K+ channel IKACh is a heteromultimer of two inwardly rectifying K(+)-channel proteins. 1995, Pubmed , Xenbase
Lape, On the nature of partial agonism in the nicotinic receptor superfamily. 2008, Pubmed
Moreno-Galindo, Relaxation gating of the acetylcholine-activated inward rectifier K+ current is mediated by intrinsic voltage sensitivity of the muscarinic receptor. 2011, Pubmed
Natochin, Mutational analysis of the Asn residue essential for RGS protein binding to G-proteins. 1998, Pubmed
Navarro-Polanco, Conformational changes in the M2 muscarinic receptor induced by membrane voltage and agonist binding. 2011, Pubmed
Neubig, Regulators of G-protein signalling as new central nervous system drug targets. 2002, Pubmed
Noma, Relaxation of the ACh-induced potassium current in the rabbit sinoatrial node cell. 1978, Pubmed
Roman, Identification of small-molecule inhibitors of RGS4 using a high-throughput flow cytometry protein interaction assay. 2007, Pubmed
Ross, GTPase-activating proteins for heterotrimeric G proteins: regulators of G protein signaling (RGS) and RGS-like proteins. 2000, Pubmed
Ruiz de Azua, RGS4 is a negative regulator of insulin release from pancreatic beta-cells in vitro and in vivo. 2010, Pubmed
Sattar, The dynamic role of regulator of G-protein signalling (RGS) proteins in partial agonism. 2014, Pubmed
Seifert, Functional differences between full and partial agonists: evidence for ligand-specific receptor conformations. 2001, Pubmed
Srinivasa, Mechanism of RGS4, a GTPase-activating protein for G protein alpha subunits. 1998, Pubmed
Tota, Partial agonist effects on the interaction between the atrial muscarinic receptor and the inhibitory guanine nucleotide-binding protein in a reconstituted system. 1990, Pubmed
Wang, DHHC protein-dependent palmitoylation protects regulator of G-protein signaling 4 from proteasome degradation. 2010, Pubmed
Wang, Pilocarpine modulates the cellular electrical properties of mammalian hearts by activating a cardiac M3 receptor and a K+ current. 1999, Pubmed
Yamada, G protein regulation of potassium ion channels. 1998, Pubmed
Zahn, Allosteric modulation of muscarinic receptor signaling: alcuronium-induced conversion of pilocarpine from an agonist into an antagonist. 2002, Pubmed
Zheng, Divergence of RGS proteins: evidence for the existence of six mammalian RGS subfamilies. 1999, Pubmed
Zhu, Mechanistic explanation for the unique pharmacologic properties of receptor partial agonists. 2005, Pubmed