Proteomic study of Pichia jadinii M9 revealed differential proteins expression under chromium stress

VERÓNICA IRAZUSTA; CRISTINA ESTEVEZ; LUCÍA INÉS FIGUEROA DE CASTELLANOS

Mar del Plata

Congreso; SAMIGE Sociedad Argentina de Microbiología General; 2012

Organisms subjected to metal exposures in their natural environments generally have had develop resistance mechanisms. Pichia jadinii M9 (GenBank accesion number FJ865435), yeast isolated from textile factory effluents in Tucumán, Argentina, has the ability of supporting high amounts of chromium metal by a slow down in its growth rate. In order to understand the mechanism involved in Pichia jadinii M9 resistance to chromium it was conducted a proteomic approach. Analyzing by mono-dimensional gel electrophoresis the crude cells extracts, it was observed differential bands expressions between cells with or without chromium. Further, with the aim of studying these differences, two-dimensional electrophoresis analyses was carried out by means of an isoelectric focusing (11-cm strips, 3-11NL pH) and a SDS-PAGE (12.5%) for the first and second dimensions, respectively. Gels were coomassie-stained, scanned and analyzed with Image Master Program. 2-D analysis of Pichia jadinii M9 revealed that 18 h chromium exposure produced an over-expression of 17 proteins. Identification of differentially expressed proteins was performed by MALDI TOF/TOF. Eleven of 17 spots identified belonged to heat shock proteins. Elongation factor 1 alpha, methionine synthase, peptidyl-prolyl cis-trans isomerase and vacuolar ATPase VI complex A, were also found over-expressed at high chromium concentrations. The results obtained in the present work show that when exposing Pichia jadinii M9 to 0.5 mM chromium concentration, it is produced a differential protein expressions, some of them directly involved in cell resistance mechanism