A long term objective of our research effort is to define factors that influence the specificity and efficiency of signal processing by heterotrimeric G-proteins. Accessory proteins provide alternative modes of signal input to G-protein signaling systems and/ or segregate a signaling complex to microdomains of the cell, regulate the basal activity, efficiency and/or specificity of signal transfer. Our goals are to define such accessory proteins, their mechanism of regulation and their role in various diseases. One such group of accessory proteins is defined by the family of Activators of G-protein signaling or AGS proteins discovered in a yeast-based functional screen for receptor-independent activators of G-protein signaling. This proposal focuses on AGS3 and related Group II AGS proteins.
SPECIFIC AIM #1 Identify mechanisms regulating the interaction of AGS3 with G-proteins.
SPECIFIC AIM #2 Define the functional impact of a loss of AGS3 in the intact animal.
SPECIFIC AIM #3 Identify and characterize additional disease- or adaptation-specific AGS proteins using a yeast-based functional screen for receptor independent activators of G116, Gs1, Gi12, and Gi13. AGS3 and related accessory proteins provide unexpected mechanisms for regulation of the G-protein activation cycle and have opened up a new area of research related to the cellular role of G-proteins as signal transducers. The concepts advanced with their discovery provide unexpected avenues for therapeutics and understanding disease mechanisms.

Public Health Relevance

The work proposed in this application focuses on basic mechanisms for regulation of a major system that controls function of various tissues in the body including brain, heart and adipose. The area of investigation has merit from the perspective of disease diagnostics and the development of new therapeutic strategies.

Agency
National Institute of Health (NIH)
Institute
National Institute on Drug Abuse (NIDA)
Type
Research Project (R01)
Project #
5R01DA025896-23
Application #
8214669
Study Section
Molecular Neuropharmacology and Signaling Study Section (MNPS)
Program Officer
Pollock, Jonathan D
Project Start
1987-07-01
Project End
2014-01-31
Budget Start
2012-02-01
Budget End
2014-01-31
Support Year
23
Fiscal Year
2012
Total Cost
$314,823
Indirect Cost
$98,755
Name
Medical University of South Carolina
Department
Pharmacology
Type
Schools of Medicine
DUNS #
183710748
City
Charleston
State
SC
Country
United States
Zip Code
29425
Vural, Ali; Fadillioglu, Ersin; Kelesoglu, Fatih et al. (2018) Role of G-proteins and phosphorylation in the distribution of AGS3 to cell puncta. J Cell Sci 131:
Robichaux 3rd, William G; Branham-O'Connor, Melissa; Hwang, Il-Young et al. (2017) Regulation of Chemokine Signal Integration by Activator of G-Protein Signaling 4 (AGS4). J Pharmacol Exp Ther 360:424-433
Robichaux 3rd, William G; Oner, Sukru S; Lanier, Stephen M et al. (2015) Direct Coupling of a Seven-Transmembrane-Span Receptor to a G?i G-Protein Regulatory Motif Complex. Mol Pharmacol 88:231-7
Blumer, Joe B; Lanier, Stephen M (2014) Activators of G protein signaling exhibit broad functionality and define a distinct core signaling triad. Mol Pharmacol 85:388-96
Oner, Sukru Sadik; Blumer, Joe B; Lanier, Stephen M (2013) Group II activators of G-protein signaling: monitoring the interaction of Gýý with the G-protein regulatory motif in the intact cell. Methods Enzymol 522:153-67
Oner, Sukru Sadik; Maher, Ellen M; Gabay, Meital et al. (2013) Regulation of the G-protein regulatory-G?i signaling complex by nonreceptor guanine nucleotide exchange factors. J Biol Chem 288:3003-15
Oner, Sukru S; Vural, Ali; Lanier, Stephen M (2013) Translocation of activator of G-protein signaling 3 to the Golgi apparatus in response to receptor activation and its effect on the trans-Golgi network. J Biol Chem 288:24091-103
Kwon, Michelle; Pavlov, Tengis S; Nozu, Kandai et al. (2012) G-protein signaling modulator 1 deficiency accelerates cystic disease in an orthologous mouse model of autosomal dominant polycystic kidney disease. Proc Natl Acad Sci U S A 109:21462-7
Blumer, J B; Oner, S S; Lanier, S M (2012) Group II activators of G-protein signalling and proteins containing a G-protein regulatory motif. Acta Physiol (Oxf) 204:202-18
Chan, PuiYee; Gabay, Meital; Wright, Forrest A et al. (2011) Purification of heterotrimeric G protein alpha subunits by GST-Ric-8 association: primary characterization of purified G alpha(olf). J Biol Chem 286:2625-35

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