We investigate signal transduction mechanisms with the ultimate goal of elucidating the molecular basis of human diseases and developing novel therapeutic approaches. Our main interest is in heterotrimeric G proteins, which are molecular switches that relay extracellular signals. Heterotrimeric G proteins are primarily activated by G protein-coupled receptors (GPCRs) located at the plasma membrane. However, our lab focuses on a group of cytoplasmic factors that mimic the action of GPCRs by directly activating heterotrimeric G proteins. These non-receptor activators “rewire” signal transduction in different pathological settings, including cancer, fibrosis, insulin resistance and kidney failure, among many others. Our current efforts are focused on (i) identifying the members of this group of non-receptor activators, (ii) defining their role in normal and pathological scenarios, (iii) characterizing the molecular mechanisms by which they are regulated, (iv) understanding the structural basis for their action on G proteins and (v) developing tools to specifically target them. We are exploring this unconventional aspect of G protein signaling in the context of cancer, embryonic development and neurotransmission. Our multidisciplinary approach includes in vitro biochemistry to characterize protein complexes, culture cells and model organisms (yeast, frog embryos) for functional studies and synthetic biology tools to manipulate and monitor signaling with exquisite spatiotemporal resolution.
Postdoctoral positions available.
Jessica Chen- Undergraduate Student
Elena Green- Undergraduate Student
Myles Zhou- Undergraduate Student
Kimberly Chen- Undergraduate Student
- Marivin A, Ho RX, Garcia-Marcos M. DAPLE orchestrates apical actomyosin assembly from junctional polarity complexes. J Cell Biol. 2022 May 02; 221(5). PMID: 35389423
- Garcia-Marcos M. Complementary biosensors reveal different G-protein signaling modes triggered by GPCRs and non-receptor activators. eLife. 2021 Mar 31;10:e65620. PMID: 33787494
- Garcia-Marcos M, Parag-Sharma K, Marivin A, Maziarz M, Luebbers A, Nguyen LT. Optogenetic activation of heterotrimeric G-proteins by LOV2GIVe, a rationally engineered modular protein. Elife. 2020 Sep 16;9:e60155. doi: 10.7554/eLife.60155. PMID: 32936073
- Maziarz M, Park J-C, Leyme A, Marivin A, Garcia-Lopez A, Patel PP, Garcia-Marcos M. Revealing the Activity of Trimeric G-proteins in Live Cells with a Versatile Biosensor Design. Cell: published:July 06, 2020. DOI:https://doi.org/10.1016/j.cell.2020.06.020
- DiGiacomo V, Maziarz M, Luebbers A, Norris JM, Laksono P, Garcia-Marcos M. Probing the mutational landscape of regulators of G Protein signaling proteins in cancer. Science Signaling. 2020 Feb 4;13(617). pii: eaax8620. PMID: 32019900.
- Marivin A, Morozova V, Walawalkar I, Leyme A, Kretov DA, Cifuentes D, Dominguez I, Garcia-Marcos M. GPCR-independent activation of G proteins promotes apical cell constriction in vivo. Journal of Cell Biology. 2019; May 6;218(5):1743-1763. PMID: 30948426.
- Maziarz M, Leyme A, Marivin A, Luebbers A, Patel PP, Chen Z, Sprang SR, Garcia-Marcos M. Atypical activation of Gαq by the oncogenic mutation Q209P. Journal of Biological Chemistry. 2018; PMID: 30352874
- Maziarz M, Broselid S, DiGiacomo V, Park JC, Luebbers A, Garcia-Navarrete L, Blanco-Canosa JB, Baillie GS, Garcia-Marcos M. A biochemical and genetic discovery pipeline identifies PLCδ4b as a non-receptor activator of heterotrimeric G proteins. Journal of Biological Chemistry. 2018; PMID: 30194280.
- Leyme A, Marivin A, Maziarz M, DiGiacomo V, Papakonstantinou MP, Patel PP, Blanco-Canosa JB, Walawalkar I, Rodriguez-Davila G, Dominguez I, Garcia-Marcos M. Specific inhibition of GPCR-independent signaling by a rationally engineered protein. Proceedings of the National Academy of Sciences. 2017 Nov 28;114(48):E10319-E10328. PMID: 29133411
- de Opakua AI, Parag-Sharma K, DiGiacomo V, Merino N, Leyme A, Marivin A, Villate M, Nguyen LT, de la Cruz-Morcillo MA, Blanco-Canosa JB, Ramachandran S, Baillie GS, Cerione RA, Blanco FJ, Garcia-Marcos M. Molecular mechanism of Gαi activation by non-GPCR proteins with a Gα-Binding and Activating motif. Nature Communications. May 18;8:15163. PMID: 28516903
- Marivin A., Leyme A., Parag-Sharma K., DiGiacomo V., Cheung A.Y., Nguyen L.T., Dominguez I. Garcia-Marcos M. Dominant negative Gα subunits as a novel mechanism of trimeric G protein signaling dysregulation in human disease. Science Signaling. Apr 12;9(423):ra37. PMID: 27072656.
- Leyme A, Marivin A, Perez-Gutierrez L, Nguyen LT, Garcia-Marcos M. Integrins activate trimeric G proteins via the nonreceptor protein GIV/Girdin. Journal of Cell Biology. 2015 Sep 28;210(7):1165-84. PMID: 26391662.
- Ghosh P, Garcia-Marcos M. Do All Roads Lead to Rome in G-Protein Activation? Trends in Biochemical Sciences. 2019 Nov 18. pii: S0968-0004(19)30211-7. PMID: 31753703.
- DiGiacomo V, Marivin A, Garcia-Marcos M. When Heterotrimeric G Proteins Are Not Activated by G Protein-Coupled Receptors: Structural Insights and Evolutionary Conservation. 2018; Jan 23; 57(3):255-257. PMID: 29035513.
- Garcia-Marcos M., Ghosh P., Farquhar M.G. GIV/ Girdin transmits signals from multiple receptors by triggering trimeric G protein activation. Journal of Biological Chemistry. 2015. Mar 13;290(11):6697-704. PMID: 25605737.
Complete list can be found at BU Profiles