Characterization of the interaction of GAPC and SINAL7 in plants

PERALTA, D.A.; NARDI, C.F.; BUSI, M.V.; GOMEZ-CASATI, D.F

Potrero de los Funes

Congreso; XLVII Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB),; 2011

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB),

The glycolytic enzyme Glyceraldehyde-3P dehydrogenase(GAPC), has been characterized in a wide range of organisms. Thisenzyme was found in the nucleus, cytoplasm and associated to themitochondrial external membrane in plants. It has been postulatedthat GAPC may have an important role in apoptosis, genetranscription in neurons and DNA reparation. However, little isknown about the possible functions of this protein in addition to itsparticipation in glycolysis, mainly in higher plants. It was reportedthat human and murine GAPC binds a E3-ubiquitin-ligase andtranslocated to the nucleus. Besides, it has been informed thatGAPC interacts with Siah1, an E3-ubiquitin-ligase by two hybridassay. We recently identified SINA-L7, a plant homolog of Siah1.We found that SINA-L7 is induced in GAPC-1 knock out plants.Bioinformatic analysis predicts the existence of a RING fingerdomain in SINA-L7 and preliminary results showed that SINA-L7has a E3 ubiquitin ligase activity. In addition, far western blottingexperiments showed that SINA-L7 physically interacts with bothGAPC isoforms from A. thaliana. Our results suggest that GAPCisoforms and SINA-L7 may participate in a retrograde signalingmechanism between the nucleus and mitochondria in plant cells