Tel: +44 (0) 1865 275029 (Lab) , +44(0) 1865 275024 (Office)
Chloroplast protein import in Arabidopsis.
Chloroplasts are organelles of endosymbiotic origin that perform essential functions in plants. Although chloroplasts do contain their own DNA, most of the plastid proteins are nucleus-encoded, synthesized in precursor form in the cytosol, and transported into the chloroplasts post-translationally. Import of these preproteins is generally mediated via the envelope complexes TOC and TIC (Translocon at the Outer/Inner envelope membrane of Chloroplasts). Currently, I am participating in two research projects that involve the TOC and TIC translocons, respectively:
“Analyses of the TOC complexes that define different client-specific import pathways. “
Over the last years, biochemical and genetic studies have identified the core components of the TOC complex: Toc159 (and its homologues Toc132 and Toc120), Toc34 (and its homologue Toc33) and Toc75. In Arabidopsis, it has been proposed that, while Toc159 and Toc33 are involved in the recognition of photosythetic (PS) preproteins, Toc132/Toc120 and Toc34 participate in the recognition of non-PS precursors. My research focuses in the existence of such client-specific import pathways.
“Analysis of the role of the stromal chaperone Hsp93.”
It is generally considered that preproteins are imported in an unfolded state, and that this process is energy-dependent. Various chaperones and cochaperones have been proposed to mediate different stages of chloroplast import. At the final stages of this process, it has been long assumed that the stromal Hsp100-type chaperone, Hsp93/ClpC, cooperates with Tic110 and Tic40 (at the TIC complex) in one motor complex. My main research in the lab focuses on the functional analysis of the Hsp93/ClpC chaperone at the chloroplast envelope. I am using molecular, biochemical, genetic and cellular approaches to get further knowledge on the involvement of this chaperone during preprotein translocation and on its recently proposed role in protein quality control at the chloroplast envelope.
Flores-Pérez, Ú., Bedard, J., Tanabe, N., Lymperopoulus, P., Clarke, A.K., and Jarvis, P.. (2015). Functional analysis of the Hsp93/ClpC chaperone at the chloroplast envelope. Plant Physiol. (submitted).
Trösch, R., Töpel, M., Flores-Pérez, Ú. and Jarvis, P. (2015) Genetic and physical interaction studies reveal functional similarities between ALBINO3 and ALBINO4 in Arabidopsis. Plant Physiol. doi:10.1104/pp.15.00376.
Flores-Pérez, Ú. and Jarvis, P. (2015) Isolation of Chloroplasts, their Sub-Organellar Compartments and Membranes. In “The Isolation of Plant Organelles and Structures: Methods and Protocols”, MiMB. (Nicolas Taylor and Harvey Millar, eds.). Springer. (in press).
Flores-Pérez, Ú. and Jarvis, P. (2013) Molecular chaperone involvement in chloroplast protein import. Biochim. Biophys. Acta 1833: 332-340.
Flores-Pérez, Ú. and Rodríguez-Concepción, M. (2012) Carotenoids. In: Phytonutrients (A. Salter, G. Tucker, H. Wiseman, eds). Blackwell Publishing. Oxford, UK. ISBN 9781405131513.
Flores-Pérez, Ú., Pérez-Gil, J., Closa, M., Wright, L.P., Botella-Pavía, P., Phillips, M.A., Ferrer, A., Gershenzon, J., and Rodríguez-Concepción, M, (2010). PLEIOTROPIC REGULATORY LOCUS 1 (PRL1) integrates the regulation of sugar responses with isoprenoid metabolism in Arabidopsis. Mol Plant 3(1):101.
Peña-Sánchez, J., Poggio, S., Flores-Pérez, Ú., Osorio A, Domenzain C, Dreyfus G, Camarena L. (2009). Identification of the binding site of the s54 hetero-oligomeric FleQ/FleT activator in the flagellar promoters of Rhodobacter sphaeroides. Microbiology 155(Pt 5):1669.
Gas, E., Flores-Pérez, Ú., Sauret-Güeto, S. and Rodríguez-Concepción, M. (2009). Hunting for plant nitric oxide synthase provides new evidence of a central role for plastids in nitric oxide metabolism. Plant Cell 21(1):18-23.
Flores-Pérez, Ú., Sauret-Güeto, S., Gas, E., Jarvis, P., and Rodríguez-Concepción, M. (2008). A mutant impaired in the production of plastome-encoded proteins uncovers a mechanism for the homeostasis of isoprenoid biosynthetic enzymes in Arabidopsis plastids. Plant Cell 20(5):1303-15.
Flores-Pérez, Ú., Pérez-Gil, J., Rodríguez-Villalón, A., Gil, M.J., Vera, P., and Rodríguez-Concepción, M. (2008). Contribution of hydroxymethylbutenyl diphosphate synthase to carotenoid biosynthesis in bacteria and plants. Biochem. Biophys. Res. Commun. 371(3):510-514.
Sauret-Güeto, S., Botella-Pavía, P., Flores-Pérez, Ú., Martínez-García, J.F., San Román, C., León, P., Boronat, A., and Rodríguez-Concepción, M. (2006). Plastid cues posttranscriptionally regulate the accumulation of key enzymes of the methylerythritol phosphate pathway in Arabidopsis. Plant Physiol. 141(1):75-84.