Effect of tunicamycin on potato aspartic proteinases secretion

PAGANO MR, MENDIETA JR, MUÑOZ F, NISHI C, DALEO GR, GUEVARA MG

Pinamar, Buenos Aires, Argentina

Congreso; X Congreso of Panamerican Association for Biochemistry and Molecular Biology (PABMB), XLI Reunión anual de la Sociedad Argentina de Investigación Bioquímica y Biología Molecular (SAIB), XX Reunión anual de la Sociedad Argentina de Neuroquímica (SAN); 2005

Effect of tunicamycin on potato aspartic proteinases secretion. 2005 Pagano MR, Mendieta JR,  Muñoz F, Nishi C, Daleo GR, Guevara MG. BIOCELL PL-P64. ISSN 0327-9545. Apparently, the effect of glycosylation is protein specific. Plant aspartic proteinases (AP) contain two or more consensus N-­glycosylation sites; however, the importance of those is not well understood. We have previously reported that the effect of the glycosylation of StAP (Solanum tuberosum Aspartic Proteinases) is important for their antimicrobial activity, because it would increase the capacity to induce membrane permeabilization. In this work, we investigated the effects of tunicamycin on the secretion of StAP1 and StAP3 to the apoplast. To inhibit glycosylation, potato tubers and leaves were treated during 12, 24 y 48 hours with or without 0.5 mg/ml of tunicamycin. After treatment, total proteins were analysed by SDS-PAGE and, potato aspartic proteinases by Western blot. The results showed that the treatment with tunicamycin did not affect the protein pattern of tubers and leaves. Aspartic proteases were induced by wounding; however, when tubers and leaves were treated with the inhibitor, the basal level of those proteases were not modified. On the other hand, also we observed that in tubers treated during 24 or 48 hr with tunicamycin, a protease inhibitors present in the apoplast were not secreted, suggesting that glycosylation would be involved in the secretion these pathogenesis related proteins.