scholarly journals Gα and regulator of G-protein signaling (RGS) protein pairs maintain functional compatibility and conserved interaction interfaces throughout evolution despite frequent loss of RGS proteins in plants

2016 ◽  
Vol 216 (2) ◽  
pp. 562-575 ◽  
Author(s):  
Dieter Hackenberg ◽  
Michael R. McKain ◽  
Soon Goo Lee ◽  
Swarup Roy Choudhury ◽  
Tyler McCann ◽  
...  
2000 ◽  
Vol 14 (16) ◽  
pp. 2003-2014 ◽  
Author(s):  
Meng-Qiu Dong ◽  
Daniel Chase ◽  
Georgia A. Patikoglou ◽  
Michael R. Koelle

Regulators of G protein signaling (RGS proteins) inhibit heterotrimeric G protein signaling by activating G protein GTPase activity. Many mammalian RGS proteins are expressed in the brain and can act in vitro on the neural G protein Go, but the biological purpose of this multiplicity of regulators is not clear. We have analyzed all 13 RGS genes in Caenorhabditis elegans and found that three of them influence the aspect of egg-laying behavior controlled by Go signaling. A previously studied RGS protein, EGL-10, affects egg laying under all conditions tested. The other two RGS proteins, RGS-1 and RGS-2, act as Go GTPase activators in vitro but, unlike EGL-10, they do not strongly affect egg laying when worms are allowed to feed constantly. However, rgs-1; rgs-2double mutants fail to rapidly induce egg-laying behavior when refed after starvation. Thus EGL-10 sets baseline levels of signaling, while RGS-1 and RGS-2 appear to redundantly alter signaling to cause appropriate behavioral responses to food.


2010 ◽  
Vol 21 (2) ◽  
pp. 232-243 ◽  
Author(s):  
Morwenna Y. Porter ◽  
Michael R. Koelle

Regulator of G protein signaling (RGS) proteins inhibit G protein signaling by activating Gα GTPase activity, but the mechanisms that regulate RGS activity are not well understood. The mammalian R7 binding protein (R7BP) can interact with all members of the R7 family of RGS proteins, and palmitoylation of R7BP can target R7 RGS proteins to the plasma membrane in cultured cells. However, whether endogenous R7 RGS proteins in neurons require R7BP or membrane localization for function remains unclear. We have identified and knocked out the only apparent R7BP homolog in Caenorhabditis elegans, RSBP-1. Genetic studies show that loss of RSBP-1 phenocopies loss of the R7 RGS protein EAT-16, but does not disrupt function of the related R7 RGS protein EGL-10. Biochemical analyses find that EAT-16 coimmunoprecipitates with RSBP-1 and is predominantly plasma membrane-associated, whereas EGL-10 does not coimmunoprecipitate with RSBP-1 and is not predominantly membrane-associated. Mutating the conserved membrane-targeting sequence in RSBP-1 disrupts both the membrane association and function of EAT-16, demonstrating that membrane targeting by RSBP-1 is essential for EAT-16 activity. Our analysis of endogenous R7 RGS proteins in C. elegans neurons reveals key differences in the functional requirements for membrane targeting between members of this protein family.


2020 ◽  
Vol 2020 (4) ◽  
Author(s):  
Katelin E. Ahlers-Dannen ◽  
Mohammed Alqinyah ◽  
Christopher Bodle ◽  
Josephine Bou Dagher ◽  
Bandana Chakravarti ◽  
...  

Regulator of G protein Signaling, or RGS, proteins serve an important regulatory role in signaling mediated by G protein-coupled receptors (GPCRs). They all share a common RGS domain that directly interacts with active, GTP-bound Gα subunits of heterotrimeric G proteins. RGS proteins stabilize the transition state for GTP hydrolysis on Gα and thus induce a conformational change in the Gα subunit that accelerates GTP hydrolysis, thereby effectively turning off signaling cascades mediated by GPCRs. This GTPase accelerating protein (GAP) activity is the canonical mechanism of action for RGS proteins, although many also possess additional functions and domains. RGS proteins are divided into four families, R4, R7, R12 and RZ based on sequence homology, domain structure as well as specificity towards Gα subunits. For reviews on RGS proteins and their potential as therapeutic targets, see e.g. [160, 377, 411, 415, 416, 512, 519, 312, 6].


2018 ◽  
Vol 23 (4) ◽  
pp. 363-374 ◽  
Author(s):  
Christopher R. Bodle ◽  
Josephine H. Schamp ◽  
Joseph B. O’Brien ◽  
Michael P. Hayes ◽  
Meng Wu ◽  
...  

Regulator of G protein signaling (RGS) proteins temporally regulate heterotrimeric G protein signaling cascades elicited by G protein–coupled receptor activation and thus are essential for cell homeostasis. The dysregulation of RGS protein expression has been linked to several pathologies, spurring discovery efforts to identify small-molecule inhibitors of these proteins. Presented here are the results of a high-throughput screening (HTS) campaign targeting RGS17, an RGS protein reported to be inappropriately upregulated in several cancers. A screen of over 60,000 small molecules led to the identification of five hit compounds that inhibit the RGS17-Gαo protein-protein interaction. Chemical and biochemical characterization demonstrated that three of these hits inhibited the interaction through the decomposition of parent compound into reactive products under normal chemical library storage/usage conditions. Compound substructures susceptible to decomposition are reported and the decomposition process characterized, adding to the armamentarium of tools available to the screening field, allowing for the conservation of resources in follow-up efforts and more efficient identification of potentially decomposed compounds. Finally, analogues of one hit compound were tested, and the results establish the first ever structure-activity relationship (SAR) profile for a small-molecule inhibitor of RGS17.


2012 ◽  
Vol 287 (21) ◽  
pp. 17870-17881 ◽  
Author(s):  
Swarup Roy Choudhury ◽  
Corey S. Westfall ◽  
John P. Laborde ◽  
Naveen C. Bisht ◽  
Joseph M. Jez ◽  
...  

2020 ◽  
Vol 13 (617) ◽  
pp. eaax8620 ◽  
Author(s):  
Vincent DiGiacomo ◽  
Marcin Maziarz ◽  
Alex Luebbers ◽  
Jillian M. Norris ◽  
Pandu Laksono ◽  
...  

The advent of deep-sequencing techniques has revealed that mutations in G protein–coupled receptor (GPCR) signaling pathways in cancer are more prominent than was previously appreciated. An emergent theme is that cancer-associated mutations tend to cause enhanced GPCR pathway activation to favor oncogenicity. Regulators of G protein signaling (RGS) proteins are critical modulators of GPCR signaling that dampen the activity of heterotrimeric G proteins through their GTPase-accelerating protein (GAP) activity, which is conferred by a conserved domain dubbed the “RGS-box.” Here, we developed an experimental pipeline to systematically assess the mutational landscape of RGS GAPs in cancer. A pan-cancer bioinformatics analysis of the 20 RGS domains with GAP activity revealed hundreds of low-frequency mutations spread throughout the conserved RGS domain structure with a slight enrichment at positions that interface with G proteins. We empirically tested multiple mutations representing all RGS GAP subfamilies and sampling both G protein interface and noninterface positions with a scalable, yeast-based assay. Last, a subset of mutants was validated using G protein activity biosensors in mammalian cells. Our findings reveal that a sizable fraction of RGS protein mutations leads to a loss of function through various mechanisms, including disruption of the G protein–binding interface, loss of protein stability, or allosteric effects on G protein coupling. Moreover, our results also validate a scalable pipeline for the rapid characterization of cancer-associated mutations in RGS proteins.


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