Peroxiredoxin proteins over-expression by Candida fukuyamaensis RCL-3 under copper overload.

VERÓNICA IRAZUSTA; LUCAS MICHEL; LUCÍA INÉS FIGUEROA DE CASTELLANOS

Madison, Wisconsin

Congreso; 13th International Congress on Yeasts; 2012

Copper (Cu) plays an essential role in cellular metabolism due to its versatility as a biological catalyst. It is required as a catalytic cofactor in many enzymes involved in diverse cellular processes. While trace amounts of copper are essential for life, copper can easily react with oxygen or hydrogen peroxide (H2O2) generating reactive oxygen species (ROS) that may damage cell constituents through the oxidation of proteins, cleavage of DNA and RNA, and lipid peroxidation. In order to counteract this adverse aspect, all living organisms have developed defense mechanisms against ROS, allowing them to live under different stress situations. Candida fukuyamaensis RCL-3 (NCBI number AY743221), yeast strain isolated from a copper filter plant at the province of Tucumán, Argentina, has the ability of supporting high amounts of copper metal by a slowdown in its growth rate. In order to understand the mechanism involved in C. fukuyamaensis RCL-3 resistance to copper it was conducted a proteomic approach. Atomic absorption spectroscopy results showed decrease copper concentration (from 0.5 to 0.14 ± 0.05 mM) in the culture medium after 16 h inoculation. Crude cell extracts mono-dimensional gel electrophoresis revealed differential bands expressions between cells grown with or without copper. Further, with the aim of studying these differences, two-dimensional electrophoresis analyses was carried out. Gels analyzed with Image Master Program. 2-D analysis of C. fukuyamaensis RCL-3 revealed that 16 h copper exposure produced an over-expression of 40 proteins. Four of this proteins identified by MALDI TOF/TOF were found as peroxiredoxin family members. The results obtained in the present work show that when exposing C. fukuyamaensis RCL-3 to 0.5mM copper concentration, it is produced a differential protein expressions probably involved in cell resistance mechanisms.