Anno2015
AutoriPicco, Cristiana; Scholz-Starke, Joachim; Festa, Margherita; Costa, Alex; Sparla, Francesca; Trost, Paolo; Carpaneto, Armando
AbstractTrans-plasma membrane electron transfer is achieved by b-type cytochromes of different families, and plays a fundamental role in diverse cellular processes involving two interacting redox couples that are physically separated by a phospholipid bilayer, such as iron uptake and redox signaling. Despite their importance, no direct recordings of trans-plasma membrane electron currents have been described in plants. In this work, we provide robust electrophysiological evidence of trans-plasma membrane electron flow mediated by a soybean (Glycine max) cytochrome b561 associated with a dopamine beta-monooxygenase redox domain (CYBDOM), which localizes to the plasma membrane in transgenic Arabidopsis (Arabidopsis thaliana) plants and CYBDOM complementary RNA-injected Xenopus laevis oocytes. In oocytes, two-electrode voltage clamp experiments showed that CYBDOM-mediated currents were activated by extracellular electron acceptors in a concentration- and type-specific manner. Current amplitudes were voltage dependent, strongly potentiated in oocytes preinjected with ascorbate (the canonical electron donor for cytochrome b561), and abolished by mutating a highly conserved His residue (H292L) predicted to coordinate the cytoplasmic heme b group. We believe that this unique approach opens new perspectives in plant transmembrane electron transport and beyond.
RivistaPlant Physiology (bethesda)
ISSN0032-0889
Impact factor0
Volume169
Pagina inizio986
Pagina fine95
Autori IBFArmando CARPANETO, Cristiana PICCO, Joachim Johannes SCHOLZ STARKE, Margherita FESTA
Linee di Ricerca IBFMD.P01.001.001
Sedi IBFIBF.GE