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
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
Branham-O'Connor, Melissa; Robichaux 3rd, William G; Zhang, Xian-Kui et al. (2014) Defective chemokine signal integration in leukocytes lacking activator of G protein signaling 3 (AGS3). J Biol Chem 289:10738-47
Oner, Sukru Sadik; Maher, Ellen M; Gabay, Meital et al. (2013) Regulation of the G-protein regulatory-Gýýi signaling complex by nonreceptor guanine nucleotide exchange factors. J Biol Chem 288:3003-15
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 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
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
Sato, Motohiko; Hiraoka, Masahiro; Suzuki, Hiroko et al. (2011) Identification of transcription factor E3 (TFE3) as a receptor-independent activator of G?16: gene regulation by nuclear G? subunit and its activator. J Biol Chem 286:17766-76
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
Regner, Kevin R; Nozu, Kandai; Lanier, Stephen M et al. (2011) Loss of activator of G-protein signaling 3 impairs renal tubular regeneration following acute kidney injury in rodents. FASEB J 25:1844-55
Oner, Sukru Sadik; Maher, Ellen M; Breton, Billy et al. (2010) Receptor-regulated interaction of activator of G-protein signaling-4 and Galphai. J Biol Chem 285:20588-94

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