Investigador Responsable:

Jeronimo Bravo
Posición:
Teléfono: 963391760
FAX: 963690800
Email:
Dirección: Instituto de Biomedicina de Valencia. Jaime Roig 11, 46010 Valencia

Resumen de la Investigación actual.

Our group is interested in the structural characterisation of molecular mechanisms involved in cancer. We have approached this broad target by focusing on the interactions that proteins might establish with other proteins, or ligands. We pay a relevant attention to the study of interactions in order to understand the molecular mechanisms in the cell or try to interfere with anomalies or disease. We have lately been focusing on the molecular mechanisms of gene regulation both at transcriptional and translational levels.

 Projects:

1)  Genes involved in metastasis.

We are trying to establish a methodological flowchart involving the development of functional tools, interaction detection and structural characterisation experiments. We have developed functional tools trying to understand some biological aspects of genes involved in metastasis. The purpose of developing these functional tools is also to validate hypothesis generated by the analysis of the structures resolved in the laboratory. Regarding the interaction characterisation we have performed yeast two hybrid assays (using genes relevant to metastasis as bait), that will lead to the selection of targets for crystallisation, once they have been validated with the previously developed functional tools. If successful, we aim to transfer this methodological approach to other aspects of our research interests. We have already detected new interactions with BRMS1, and obtained good quality diffracting crystals of a deletion fragment. We are trying to obtain crystals of several complexes following the mentioned strategy.

 2)  Downregulation of RTK

Our aim is to develop a detailed structural understanding of the protein-protein interactions established by several adaptor proteins during the downregulation of tyrosine kinase receptors. We have mostly focused on the downregulation of the Epidermal Growth Factor Receptor (EGFR). We have combined molecular, cell biology and structural techniques in collaboration with Dr. Katrin Rittinger, National Institute for Medical Research, London, UK and Dr. Ivan Dikic, Goethe University Medical School, Frankfurt, Germany. We have characterised a new SH3 polyproline type of interaction and have identified critical residues in the proline-arginine motif of c-Cbl/Cbl-b involved in a ternary complex formation with the endocytic adaptor proteins CIN85 and b-PIX and the assembly of the endocytic machinery that governs downregulation of activated receptor tyrosine kinases. We are at the moment trying to prove whether a similar mechanism is possible for other adaptor proteins.

3)  Macromolecular complexes in yeast

Most cellular processes are carried out by macromolecular assemblies and regulated through a complex network of protein–protein interactions. Using yeast as model organism and in the context of “3D repertoire”, an integrated project funded by the European Commission under Framework 6, we aim to solve the structure of several protein complexes in yeast. Trying to minimize the risks of such a project, we have recently proposed that information about the complex modularity and hierarchy could provide a rationale for the dissection of the complexes in order to maximize success in structure determination. The idea is that whenever the purification or the crystallization of the entire complex becomes unattainable, a good strategy would be to first attempt the tightly associated cores and modules. Moreover, modules that are present in several complexes would also be good candidates in a topology based target selection strategy, as solving the structure of one of them would enable the modelling of many others. We have applied this strategy for the target selection of candidates that are being cloned in polycistronic vectors in order to validate their integrity and proceed to the structural determination. The main biological interests are complexes involved in several stages on the regulation of gene expression.

Palabras Clave.

Metastasis, macromolecular complexes, downregulation of kinase receptors, Structure of GTPases, regulation of gene expression, cancer, X-ray Crystallography

Publicaciones seleccionadas.

- Francis SM, Gas ME, Daugeron MC, Bravo J, Séraphin B. (2012). Rbg1-Tma46 dimer structure reveals new functional domains and their role in polysome recruitment. Nucleic Acids Res. [Epub ahead of print] PMID: 23002146

- Spínola-Amilibia, M., Rivera, J., Ortiz-Lombardía, M., Romero, A., Neira, J.L., Bravo, J.(2011). The structure of BRMS1 nuclear export signal and SNX6 interacting region reveals a hexamer formed by antiparallel coiled coils. Journal of Molecular Biology 411 (5), pp. 1114-1127
- Rivera, J., Megías, D., Bravo, J. (2010). Sorting nexin 6 interacts with breast cancer metastasis suppressor-1 and promotes transcriptional repression. Journal of Cellular Biochemistry 111 (6), pp. 1464-1472

- Pérez de Diego R, Sancho-Shimizu V, Lorenzo L, Puel A, Plancoulaine S, Picard C, Herman M, Cardon A, Durandy A, Bustamante J, Vallabhapurapu S, Bravo J, Warnatz K, Chaix Y, Cascarrigny F, Lebon P, Rozenberg F, Karin M, Tardieu M, Al-Muhsen S, Jouanguy E, Zhang SY, Abel L, Casanova JL. (2010). Human TRAF3 Adaptor Molecule Deficiency Leads to Impaired Toll-like Receptor 3 Response and Susceptibility to Herpes Simplex Encephalitis. Immunity 33 (3) , pp. 400-411

- Ibarrola-Villava, M., Fernandez, L.P., Pita, G., Bravo, J., Floristan, U., Sendagorta, E., Feito, M., (...), Ribas, G. (2010). Genetic analysis of three important genes in pigmentation and melanoma susceptibility: CDKN2A, MC1R and HERC2/OCA2. Experimental Dermatology 19 (9) , pp. 836-844

- Bravo, J., Neira, J.L. (2010). Folded and unfolded conformations of proteins involved in pancreatic cancer: A Layman's guide. TheScientificWorldJournal 10 , pp. 1612-1633

- Rivera, J., Megías, D., Navas, C., Bravo, J. (2009). Identification of essential sequences for cellular localization in BRMS1 metastasis suppressor. PLoS ONE 4 (7) , art. no. e6433

- Ruiz F.M., Gil-Redondo R., Morreale A., Ortiz A.R., Fábrega C., Bravo J. Structure-Based Discovery of novel non-nucleosidic DNA Alkyltransferase inhibitors: virtual screening and in vitro and in vivo activities. J Chem Inf Model 2008 Apr;48(4):844-54.

- Gasset-Rosa F., Mate M.J., Dávila-Fajardo C., Bravo J. and Giraldo R. Binding of sulphonated indigo derivatives to RepA-WH1 inhibits DNA induced protein amyloidogenesis. Nucl. Acids Res.2008  Apr;36(7):2249-56. Epub 2008 Feb 19

- J. Rivera, D. Megias and  J. Bravo. Proteomics-Based strategy to delineate the molecular mechanisms of the metastasis suppressor gene BRMS1. Journal of Proteome Research. 2007; (10):4006-18.

- Fernandez L.P., Milne R.L., Bravo J., Lopez J.M., Avilés J.A., Longo M.I., de la Cueva P., Benítez J., Lázaro P., Ribas G.  MC1R: Three novel variants and malignant melanoma association study in a Spanish population. Carcinogenesis. 2007; 28(8):1659-64

- G. Moncalián, N. Cárdenes, Y. Lissanu Deribe, M Spínola-Amilibia, I. Dikic and J. Bravo. Atypical polyproline recognition by CMS N-terminal SH3 domain. J Biol Chem. 2006 Dec 15;281(50):38845-38853. Epub 2006 Oct 3.

- Bravo J and Aloy P. (2006). Target selection for complex structural genomics. Curr Opin Struct Biol. 16: 385- 392

-Jozic D., Nayra Cárdenes N., Deribe Y.L., Moncalián G., Hoeller D., Groemping Y., Dikic I., Rittinger K., and Bravo J. (2005). Cbl promotes clustering of endocytic adaptor proteins. Nat. Struct and Mol. Biol, 12: 972-979.

Financiación.