» Articles » PMID: 21209316

A GDI (AGS3) and a GEF (GIV) Regulate Autophagy by Balancing G Protein Activity and Growth Factor Signals

Overview
Journal Mol Biol Cell
Date 2011 Jan 7
PMID 21209316
Citations 72
Authors
Affiliations
Soon will be listed here.
Abstract

Autophagy is the major catabolic process responsible for the removal of aggregated proteins and damaged organelles. Autophagy is regulated by both G proteins and growth factors, but the underlying mechanism of how they are coordinated during initiation and reversal of autophagy is unknown. Using protein-protein interaction assays, G protein enzymology, and morphological analysis, we demonstrate here that Gα-interacting, vesicle-associated protein (GIV, a. k. a. Girdin), a nonreceptor guanine nucleotide exchange factor for Gα(i3), plays a key role in regulating autophagy and that dynamic interplay between Gα(i3), activator of G-protein signaling 3 (AGS3, its guanine nucleotide dissociation inhibitor), and GIV determines whether autophagy is promoted or inhibited. We found that AGS3 directly binds light chain 3 (LC3), recruits Gα(i3) to LC3-positive membranes upon starvation, and promotes autophagy by inhibiting the G protein. Upon growth factor stimulation, GIV disrupts the Gα(i3)-AGS3 complex, releases Gα(i3) from LC3-positive membranes, enhances anti-autophagic signaling pathways, and inhibits autophagy by activating the G protein. These results provide mechanistic insights into how reversible modulation of Gα(i3) activity by AGS3 and GIV maintains the delicate equilibrium between promotion and inhibition of autophagy.

Citing Articles

Growth factor-dependent phosphorylation of Gα shapes canonical signaling by G protein-coupled receptors.

Roy S, Sinha S, Silas A, Ghassemian M, Kufareva I, Ghosh P Sci Signal. 2024; 17(839):eade8041.

PMID: 38833528 PMC: 11328959. DOI: 10.1126/scisignal.ade8041.


Heterotrimeric G protein signaling without GPCRs: The Gα-binding-and-activating (GBA) motif.

Garcia-Marcos M J Biol Chem. 2024; 300(3):105756.

PMID: 38364891 PMC: 10943482. DOI: 10.1016/j.jbc.2024.105756.


Fine-tuning GPCR-mediated neuromodulation by biasing signaling through different G protein subunits.

Park J, Luebbers A, Dao M, Semeano A, Nguyen A, Papakonstantinou M Mol Cell. 2023; 83(14):2540-2558.e12.

PMID: 37390816 PMC: 10527995. DOI: 10.1016/j.molcel.2023.06.006.


Small-molecule targeting of GPCR-independent noncanonical G-protein signaling in cancer.

Zhao J, DiGiacomo V, Ferreras-Gutierrez M, Dastjerdi S, de Opakua A, Park J Proc Natl Acad Sci U S A. 2023; 120(18):e2213140120.

PMID: 37098067 PMC: 10160980. DOI: 10.1073/pnas.2213140120.


Regulation of DNA damage response by trimeric G-proteins.

Abd El-Hafeez A, Sun N, Chakraborty A, Ear J, Roy S, Chamarthi P iScience. 2023; 26(2):105973.

PMID: 36756378 PMC: 9900518. DOI: 10.1016/j.isci.2023.105973.


References
1.
Cecconi F, Levine B . The role of autophagy in mammalian development: cell makeover rather than cell death. Dev Cell. 2008; 15(3):344-357. PMC: 2688784. DOI: 10.1016/j.devcel.2008.08.012. View

2.
Gotthardt D, Blancheteau V, Bosserhoff A, Ruppert T, Delorenzi M, Soldati T . Proteomics fingerprinting of phagosome maturation and evidence for the role of a Galpha during uptake. Mol Cell Proteomics. 2006; 5(12):2228-43. DOI: 10.1074/mcp.M600113-MCP200. View

3.
Takeda T, McQuistan T, ORLANDO R, Farquhar M . Loss of glomerular foot processes is associated with uncoupling of podocalyxin from the actin cytoskeleton. J Clin Invest. 2001; 108(2):289-301. PMC: 203027. DOI: 10.1172/JCI12539. View

4.
Wang J, Whiteman M, Lian H, Wang G, Singh A, Huang D . A non-canonical MEK/ERK signaling pathway regulates autophagy via regulating Beclin 1. J Biol Chem. 2009; 284(32):21412-24. PMC: 2755866. DOI: 10.1074/jbc.M109.026013. View

5.
Kimple R, Kimple M, Betts L, Sondek J, Siderovski D . Structural determinants for GoLoco-induced inhibition of nucleotide release by Galpha subunits. Nature. 2002; 416(6883):878-81. DOI: 10.1038/416878a. View