Characterization of the interaction of GAPC and SINAL7 in plants

PERALTA, DA; NARDI, MC; BUSI, M. V.; DIEGO FABIAN GOMEZ CASATI

Potrero de los Funes

Congreso; XLVII Reunion SAIB; 2011

SAIB

  The glycolytic enzyme Glyceraldehyde-3P dehydrogenase (GAPC), has been characterized in a wide range of organisms. This enzyme was found in the nucleus, cytoplasm and associated to the mitochondrial external membrane in plants. It has been postulated that GAPC may have an important role in apoptosis, gene transcription in neurons and DNA reparation. However, little is known about the possible functions of this protein in addition to its participation in glycolysis, mainly in higher plants. It was reported that human and murine GAPC binds a E3-ubiquitin-ligase and translocated to the nucleus. Besides, it has been informed that GAPC interacts with Siah1, an E3-ubiquitin-ligase by two hybrid assay. 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 finger domain in SINA-L7 and preliminary results showed that SINA-L7 has a E3 ubiquitin ligase activity. In addition, far western bloting experiments showed that SINA-L7 physically interacts with both GAPC isoforms from A. thaliana. Our results suggest that GAPC isoforms and SINA-L7 may participate in a retrograde signaling mechanism betweebsn the nucleus and mitochondria in plant cells.