INVESTIGADORES
ZABALETA Eduardo Julian
congresos y reuniones científicas
Título:
STEROID SYNTHESIS IN ARABIDOPSIS: IS THE MITOCHONDRIAL ELECTRON SHUTTLE ADXR-ADX-P450 INVOLVED?
Autor/es:
DISTEFANO A; BELLIDO A; FIOL D; EDUARDO JULIAN ZABALETA; PAGNUSSAT G
Lugar:
Rosario
Reunión:
Congreso; L Reuniòn Anual SAIB; 2014
Resumen:
We have identified and studied Arabidopsis mutants with an insertion in a nuclear gene encoding for a mitochondrial
adrenodoxin reductase (ADXR) that has female gametophyte development defects. In mammals and insects
mitochondria, adrenodoxin (ADX) mediates electron transfer from NADPH via ADXR to the terminal electron
acceptor, a cytochrome P450 (P450), which constitutes the first step in steroid hormones synthesis. In this work, we
study the existence of a similar steroid biosynthetic pathway in plants, which would be necessary for female
gametophyte development. Arabidopsis has an ADRX homologue and 2 ADXs located in mitochondria. However, no
mitochondrial P450s were described in Arabidopsis so far. We performed a two-hybrid screening to detect possible
ADX redox partners using ADX1 as bait.We found that the P450 CYP711A1 binds to ADX1. The interaction between
ADX1 and CYP711A1 was confirmed by BiFC assays. We also showed that this P450 has a mitochondrial
localization by means of GFP translational fusions and transient expression in Nicotiana Benthamiana. Using the same
approach we studied the subcellular localization of different P450s with a predicted signal peptide targeting
mitochondria. Two additional P450s were found localized to mitochondria and showed interaction with ADX trough
BiFC assays. The female gametophyte steroid profile will be analyzed by UL-MS-MS.