Mikel Garcia-Marcos, PhD

Associate Professor, Biochemistry

Mikel Garcia-Marcos
72 E. Concord St Silvio Conte (K)


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
(v) developing tools to specifically target them.

We are currently 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, cultured cells and model organisms (yeast, frog embryos, fish) for functional studies, and synthetic biology tools to manipulate and monitor signaling with exquisite spatiotemporal resolution..


  • University of the Basque Country, PhD
  • University of the Basque Country, BS


  • Published on 4/4/2019

    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. J Cell Biol. 2019 May 06; 218(5):1743-1763. PMID: 30948426.

    Read at: PubMed
  • Published on 10/23/2018

    Maziarz M, Leyme A, Marivin A, Luebbers A, Patel PP, Chen Z, Sprang SR, Garcia-Marcos M. Atypical activation of the G protein Gaq by the oncogenic mutation Q209P. J Biol Chem. 2018 12 21; 293(51):19586-19599. PMID: 30352874.

    Read at: PubMed
  • Published on 9/7/2018

    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 PLCd4b as a nonreceptor activator of heterotrimeric G-proteins. J Biol Chem. 2018 11 02; 293(44):16964-16983. PMID: 30194280.

    Read at: PubMed
  • Published on 5/11/2018

    Martemyanov KA, Garcia-Marcos M. Making useful gadgets with miniaturized G proteins. J Biol Chem. 2018 05 11; 293(19):7474-7475. PMID: 29752421.

    Read at: PubMed
  • Published on 11/13/2017

    Leyme A, Marivin A, Maziarz M, DiGiacomo V, Papakonstantinou MP, Patel PP, Blanco-Canosa JB, Walawalkar IA, Rodriguez-Davila G, Dominguez I, Garcia-Marcos M. Specific inhibition of GPCR-independent G protein signaling by a rationally engineered protein. Proc Natl Acad Sci U S A. 2017 11 28; 114(48):E10319-E10328. PMID: 29133411.

    Read at: PubMed
  • Published on 10/16/2017

    DiGiacomo V, Marivin A, Garcia-Marcos M. When Heterotrimeric G Proteins Are Not Activated by G Protein-Coupled Receptors: Structural Insights and Evolutionary Conservation. Biochemistry. 2018 01 23; 57(3):255-257. PMID: 29035513.

    Read at: PubMed
  • Published on 9/12/2017

    Maziarz M, Garcia-Marcos M. Rapid kinetic BRET measurements to monitor G protein activation by GPCR and non-GPCR proteins. Methods Cell Biol. 2017; 142:145-157. PMID: 28964333.

    Read at: PubMed
  • Published on 9/11/2017

    Maziarz M, Garcia-Marcos M. Fluorescence polarization assays to measure interactions between Ga subunits of heterotrimeric G proteins and regulatory motifs. Methods Cell Biol. 2017; 142:133-143. PMID: 28964332.

    Read at: PubMed
  • Published on 8/17/2017

    DiGiacomo V, de Opakua AI, Papakonstantinou MP, Nguyen LT, Merino N, Blanco-Canosa JB, Blanco FJ, Garcia-Marcos M. The Gai-GIV binding interface is a druggable protein-protein interaction. Sci Rep. 2017 08 17; 7(1):8575. PMID: 28819150.

    Read at: PubMed
  • Published on 5/18/2017

    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 Gai activation by non-GPCR proteins with a Ga-Binding and Activating motif. Nat Commun. 2017 05 18; 8:15163. PMID: 28516903.

    Read at: PubMed

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