Studies concerning the identity of the so-called 72 kDa NADP-malic enzyme

LARA, MARÍA VALERIA; MÜLLER, GABRIELA L.; MAURINO, VERÓNICA GRACIELA; SAIGO, MARIANA; BOLOGNA, FEDERICO PABLO; CASATI, PAULA; ANDREO, CARLOS SANTIAGO; DRINCOVICH, MARÍA FABIANA

PS2004 Proceedings: 13th International Congress of Photosynthesis. Photosynthesis: Fundamental Aspects to global aspects

Allen Press

Lugar: Montreal, Canadá; Año: 2004 p. 945 - 947

NADP-ME is a widely distributed enzyme implicated in diversemetabolic pathways. Plastidic and cytosolic NADP-ME isoformswere found in C3, C4 and CAM plants (Edwards & Andreo 1992,Drincovich et al 2001).At least three different batches of antibodies against purifiedNADP-ME from maize leaves (Maurino et al 1996, Tausta et al2002) and Mesembryanthemun crystallinum (Honda et al 2000) detecta 72KDa protein, suggested to be a non-photosynthetic NADP-ME.This isoform was found, among others, in maize (Maurino et al1996, 1997, Tausta et al 2002), various Flaveria species (Drincovichet al 1998), wheat (Maurino et al 1997, Casati et al 1997), and in Aloearborescent (Honda et al 2000). NADP-ME with a 72KDa apparentmolecular mass, as assessed by Coomassie stained SDS-PAGE, wasalso purified from maize roots (Maurino et al 2001), wheat stems(Casati et al 1997), Egeria densa leaves (Casati et al 2000), Apteniacordifolia leaves (Falcone et al 2003) and Ricinus communis cotyledons(Colombo et al 1998). However, the cDNA supposed to encodefor this 72KDa NADP-ME in maize roots, codifies in fact for anovel highly active 66KDa NADP-ME (Saigo et al 2004). In addition,a sequence codifying for such 72-kDa NADP-ME has not beenfound neither among the cDNA known to codify for NADP-MEsnor in the arabidopsis genome.Evidence concerning the identity of the 72KDa protein purifiedas NADP-ME from maize and detected by antibodies againstthe purified NADP-ME from leaves is presented. This 72KDa proteinmay be in fact a Heat Shock Protein (Hsp70) associated toNADP-ME.