Spatial Regulation of RGS and G Protein Signaling

Summary

Principal Investigator: Marilyn Gist Farquhar
Abstract: DESCRIPTION (provided by applicant): During the last 5-7 years, we identified several new proteins that are components of novel G protein signaling pathways. The characterization of these proteins has brought to light new roles for trimeric G proteins in cell proliferation, cell migration, and mitochondrial dynamics. Our accomplishments during the last 5 years of this grant include: 1) Discovery of a novel regulatory role for G1s in EGF receptor (EGFR) downregulation and signaling;2) Demonstration of the crucial role played by GIPC in TrkA NGF signaling and MAPK activation;3) Identification of GIV, a novel G1 binding protein, and demonstration that activation of G1i3 and its interaction with GIV is essential for cell migration and Akt activation during cell migration;4) Discovery of hNOA1 (formerly called MIG78), a new dynamin-like GTPase which may provide a link between mitochondrial dynamics, respiration and apoptosis;5) Identification of MIR16 (GDE1), a novel enzyme that provides a putative link between phosphoinositide metabolism and G protein signaling;and 6) Discovery of a new paradigm for spatial regulation of G1i signaling in clathrin-coated membrane microdomains. The overall goal of the work proposed is to further define two of these novel pathways we have discovered-namely, the role of G1i3 and GIV in cell migration and Akt signaling and the role of G1s in regulation of EGFR trafficking and signaling. We will focus on three specific aims: Specific Aim #1: To assess the functional interaction between G1i3 and GIV during cell migration. Our working model is that GIV serves as a non-receptor GEF and is the trigger that activates the signaling cascade culminating in efficient cell motility. Specific Aim #2: To investigate the spatial and temporal regulation of G1i3 and GIV's interaction and translocation from the Golgi to the PM in migrating cells. We will investigate where they interact and where G1i3 is activated using fluorescent biosensors, FRET and FRAP in living cells. Specific Aim #3: To pinpoint the mechanisms by which G1s and RGS-PX1 affect EGF receptor signaling, trafficking and sorting for degradation. We will investigate their effects on phosphorylation of EGFR, recruitment of adaptors, and downstream signaling as well as trafficking through the endosomal system, and sorting for down-regulation. These studies can be expected to provide insights into how normal cells function and the molecular basis for dysregulation of cell proliferation and migration associated with metastasis that occurs in cancer cells. Due to their crucial functions in regulating cell behavior these new molecules represent attractive targets for development of pharmacologic and anti-tumor agents.
Funding Period: 2003-04-17 - 2014-05-31
more information: NIH RePORT

Top Publications

  1. pmc GIPC is recruited by APPL to peripheral TrkA endosomes and regulates TrkA trafficking and signaling
    Tal Varsano
    Department of Cellular and Molecular Medicine, University of California San Diego, George Palade Laboratories Room 210, 9500 Gilman Drive, La Jolla, CA 92093 0651, USA
    Mol Cell Biol 26:8942-52. 2006
  2. pmc The PDZ protein GIPC regulates trafficking of the LPA1 receptor from APPL signaling endosomes and attenuates the cell's response to LPA
    Tal Varsano
    Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, California, United States of America
    PLoS ONE 7:e49227. 2012
  3. pmc Gαs promotes EEA1 endosome maturation and shuts down proliferative signaling through interaction with GIV (Girdin)
    Anthony O Beas
    Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
    Mol Biol Cell 23:4623-34. 2012
  4. pmc Functional characterization of the guanine nucleotide exchange factor (GEF) motif of GIV protein reveals a threshold effect in signaling
    Mikel Garcia-Marcos
    Department of Cellular and Molecular Medicine, University of California, San Diego, School of Medicine, La Jolla, CA 92093, USA
    Proc Natl Acad Sci U S A 109:1961-6. 2012
  5. pmc G Protein binding sites on Calnuc (nucleobindin 1) and NUCB2 (nucleobindin 2) define a new class of G(alpha)i-regulatory motifs
    Mikel Garcia-Marcos
    Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California 92093, USA
    J Biol Chem 286:28138-49. 2011
  6. pmc GIV/Girdin is a rheostat that fine-tunes growth factor signals during tumor progression
    Pradipta Ghosh
    Department of Medicine, School of Medicine, University of California San Diego, La Jolla, CA, USA
    Cell Adh Migr 5:237-48. 2011
  7. pmc Molecular basis of a novel oncogenic mutation in GNAO1
    M Garcia-Marcos
    Department of Cellular and Molecular Medicine, San Diego School of Medicine, University of California, La Jolla, CA 92093 0651, USA
    Oncogene 30:2691-6. 2011
  8. pmc In vitro generation of Plasmodium falciparum ookinetes
    Viengngeun Bounkeua
    Division of Infectious Diseases, Department of Medicine, University of California San Diego, La Jolla, California 92093 0741, USA
    Am J Trop Med Hyg 83:1187-94. 2010
  9. pmc Expression of GIV/Girdin, a metastasis-related protein, predicts patient survival in colon cancer
    Mikel Garcia-Marcos
    Department of Cellular and Molecular Medicine, George E Palade Laboratories, University of California, San Diego School of Medicine, La Jolla, CA 92093 0651, USA
    FASEB J 25:590-9. 2011
  10. pmc A G{alpha}i-GIV molecular complex binds epidermal growth factor receptor and determines whether cells migrate or proliferate
    Pradipta Ghosh
    Department of Cellular and Molecular Medicine and Medicine, School of Medicine, University of California San Diego, La Jolla, CA 92093, USA
    Mol Biol Cell 21:2338-54. 2010

Research Grants

  1. Modulation of G proteins by Growth Factors
    Pradipta Ghosh; Fiscal Year: 2013
  2. TSH RECEPTOR MULTIMERIZATION
    TERRY FRANCIS DAVIES; Fiscal Year: 2013
  3. Genetic and physiological mechanisms of temperature detection and compensation
    Piali Sengupta; Fiscal Year: 2013
  4. CYTOSKELETAL REGULATION OF VESICLE TRANSPORT IN LIVER
    MARK A MC NIVEN; Fiscal Year: 2013
  5. Pathophysiology of Alveolar Epithelial Lung Injury
    Jacob I Sznajder; Fiscal Year: 2013
  6. Digitalis-Induced Signaling by Cardiac Na+/K+-ATPase
    Amir Askari; Fiscal Year: 2013
  7. Cellular Pharmacology of Kappa Opiod Receptor
    Lee Yuan Liu-Chen; Fiscal Year: 2013
  8. RAGE and Mechanisms of Vascular Dysfunction
    Shi Fang Yan; Fiscal Year: 2013

Detail Information

Publications17

  1. pmc GIPC is recruited by APPL to peripheral TrkA endosomes and regulates TrkA trafficking and signaling
    Tal Varsano
    Department of Cellular and Molecular Medicine, University of California San Diego, George Palade Laboratories Room 210, 9500 Gilman Drive, La Jolla, CA 92093 0651, USA
    Mol Cell Biol 26:8942-52. 2006
    ..We conclude that GIPC, following its recruitment to TrkA by APPL, plays a key role in TrkA trafficking and signaling from endosomes...
  2. pmc The PDZ protein GIPC regulates trafficking of the LPA1 receptor from APPL signaling endosomes and attenuates the cell's response to LPA
    Tal Varsano
    Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, California, United States of America
    PLoS ONE 7:e49227. 2012
    ..We propose that GIPC binds LPA(1) and promotes its trafficking from APPL-containing signaling endosomes to EEA1 early endosomes and thus attenuates LPA-mediated Akt signaling from APPL endosomes...
  3. pmc Gαs promotes EEA1 endosome maturation and shuts down proliferative signaling through interaction with GIV (Girdin)
    Anthony O Beas
    Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
    Mol Biol Cell 23:4623-34. 2012
    ....
  4. pmc Functional characterization of the guanine nucleotide exchange factor (GEF) motif of GIV protein reveals a threshold effect in signaling
    Mikel Garcia-Marcos
    Department of Cellular and Molecular Medicine, University of California, San Diego, School of Medicine, La Jolla, CA 92093, USA
    Proc Natl Acad Sci U S A 109:1961-6. 2012
    ..This functional characterization of GIV's GEF motif provides insights into the molecular interactions between nonreceptor GEFs and G proteins and the mechanisms that govern this signal transduction pathway...
  5. pmc G Protein binding sites on Calnuc (nucleobindin 1) and NUCB2 (nucleobindin 2) define a new class of G(alpha)i-regulatory motifs
    Mikel Garcia-Marcos
    Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California 92093, USA
    J Biol Chem 286:28138-49. 2011
    ..These findings provide the structural basis for the properties of Calnuc and NUCB2 binding to Gα subunits and its regulation by calcium ions...
  6. pmc GIV/Girdin is a rheostat that fine-tunes growth factor signals during tumor progression
    Pradipta Ghosh
    Department of Medicine, School of Medicine, University of California San Diego, La Jolla, CA, USA
    Cell Adh Migr 5:237-48. 2011
    ..Based on the fact that GIV grades incoming signals initiated by ligand-activated receptors by linking them to cyclical activation of G proteins, we propose that GIV is a molecular rheostat for signal transduction...
  7. pmc Molecular basis of a novel oncogenic mutation in GNAO1
    M Garcia-Marcos
    Department of Cellular and Molecular Medicine, San Diego School of Medicine, University of California, La Jolla, CA 92093 0651, USA
    Oncogene 30:2691-6. 2011
    ....
  8. pmc In vitro generation of Plasmodium falciparum ookinetes
    Viengngeun Bounkeua
    Division of Infectious Diseases, Department of Medicine, University of California San Diego, La Jolla, California 92093 0741, USA
    Am J Trop Med Hyg 83:1187-94. 2010
    ..falciparum ookinetes per 10 mL culture was observed, with ookinete transformation present in 10-40% of all parasite forms. Transmission electron micrographs of cultured parasites confirmed ookinete development...
  9. pmc Expression of GIV/Girdin, a metastasis-related protein, predicts patient survival in colon cancer
    Mikel Garcia-Marcos
    Department of Cellular and Molecular Medicine, George E Palade Laboratories, University of California, San Diego School of Medicine, La Jolla, CA 92093 0651, USA
    FASEB J 25:590-9. 2011
    ..We conclude that GIV-fl is a novel metastasis-related protein and an independent adverse prognosticator that may serve as a useful adjunct to traditional staging strategies in colorectal carcinoma...
  10. pmc A G{alpha}i-GIV molecular complex binds epidermal growth factor receptor and determines whether cells migrate or proliferate
    Pradipta Ghosh
    Department of Cellular and Molecular Medicine and Medicine, School of Medicine, University of California San Diego, La Jolla, CA 92093, USA
    Mol Biol Cell 21:2338-54. 2010
    ..Thus, inclusion or exclusion of GIV's GEF motif, which activates Galphai, modulates EGFR signaling, generates migration-proliferation dichotomy, and most likely influences cancer progression...
  11. pmc A structural determinant that renders G alpha(i) sensitive to activation by GIV/girdin is required to promote cell migration
    Mikel Garcia-Marcos
    Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California 92093, USA
    J Biol Chem 285:12765-77. 2010
    ....
  12. pmc GIV is a nonreceptor GEF for G alpha i with a unique motif that regulates Akt signaling
    Mikel Garcia-Marcos
    Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, CA 92093, USA
    Proc Natl Acad Sci U S A 106:3178-83. 2009
    ....
  13. pmc hNOA1 interacts with complex I and DAP3 and regulates mitochondrial respiration and apoptosis
    Tingdong Tang
    Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California 92093 0651, USA
    J Biol Chem 284:5414-24. 2009
    ..Thus, based on its interactions with both Complex I and DAP3, hNOA1 may play a role in mitochondrial respiration and apoptosis...
  14. pmc Activation of Galphai3 triggers cell migration via regulation of GIV
    Pradipta Ghosh
    Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
    J Cell Biol 182:381-93. 2008
    ....
  15. pmc Loss of the inactive myotubularin-related phosphatase Mtmr13 leads to a Charcot-Marie-Tooth 4B2-like peripheral neuropathy in mice
    Fred L Robinson
    Department of Pharmacology, University of California at San Diego, La Jolla, CA 92093, USA
    Proc Natl Acad Sci U S A 105:4916-21. 2008
    ..Mtmr13-deficient mice will be an essential tool for studying how the loss of MTMR13 leads to CMT4B2...
  16. pmc Essential role of RGS-PX1/sorting nexin 13 in mouse development and regulation of endocytosis dynamics
    Bin Zheng
    Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, CA 92093 0651, USA
    Proc Natl Acad Sci U S A 103:16776-81. 2006
    ..Taken together, our findings demonstrate an essential role for RGS-PX1/SNX13 in mouse development and provide previously undescribed insights into its cellular function in the regulation of endocytosis dynamics...
  17. pmc Protein kinase C-theta (PKCθ) phosphorylates and inhibits the guanine exchange factor, GIV/Girdin
    Inmaculada López-Sánchez
    Department of Medicine, University of California at San Diego School of Medicine, La Jolla, CA 92093, USA
    Proc Natl Acad Sci U S A 110:5510-5. 2013
    ..This phosphoevent constitutes the only regulatory pathway described for terminating signaling by any of the growing family of nonreceptor GEFs that modulate G-protein activity...

Research Grants30

  1. Modulation of G proteins by Growth Factors
    Pradipta Ghosh; Fiscal Year: 2013
    ....
  2. TSH RECEPTOR MULTIMERIZATION
    TERRY FRANCIS DAVIES; Fiscal Year: 2013
    ....
  3. Genetic and physiological mechanisms of temperature detection and compensation
    Piali Sengupta; Fiscal Year: 2013
    ..compensate for temperature fluctuations? 4) What defines the limits of the range in which these homeostatic mechanisms operate? 5) What are the common principles of temperature detection and compensation among species? ..
  4. CYTOSKELETAL REGULATION OF VESICLE TRANSPORT IN LIVER
    MARK A MC NIVEN; Fiscal Year: 2013
    ..The information gathered by these studies will help identify strategies for the treatment and prevention of diseases that affect basic liver function. ..
  5. Pathophysiology of Alveolar Epithelial Lung Injury
    Jacob I Sznajder; Fiscal Year: 2013
    ..The insights gained from the data generated from these studies will provide novel molecular targets for the development of new therapeutic strategies to treat patients with lung injury. ..
  6. Digitalis-Induced Signaling by Cardiac Na+/K+-ATPase
    Amir Askari; Fiscal Year: 2013
    ..abstract_text> ..
  7. Cellular Pharmacology of Kappa Opiod Receptor
    Lee Yuan Liu-Chen; Fiscal Year: 2013
    ..In addition, such understanding will have important implications for other membrane bound receptors since these regulatory mechanisms of export are likely to be applicable to some other proteins. ..
  8. RAGE and Mechanisms of Vascular Dysfunction
    Shi Fang Yan; Fiscal Year: 2013
    ..Using novel and state-of-the-art techniques, floxed mice and molecular approaches to gene regulation, we are well-positioned to lead the study of RAGE in the next cycle of this Program. ..