Differential protein expression associated with heat stress in Antarctic microalga

Abstract

We used proteomic approaches to study the survival and defense mechanisms of Antarctic microalga under heat stress. The microalga was cultured for optimal growth at 4 degrees C, the temperature was increased to 15 degrees C, and the resultant differentially expressed proteins induced by heat stress were analyzed by mass spectrometry following two-dimensional gel electrophoresis. Orthologues of 22 proteins showed more than two-fold changes in abundance; of these, 8 proteins were up-regulated, and 14 were down-regulated. In addition, changes in the enzyme activities and isozyme profiles of catalase, aldehyde dehydrogenase, superoxide dismutase, glutathione reductase, and ascorbate peroxidase were investigated using an in-gel activity-staining method. Alterations in protein expression and antioxidant enzyme activity in Antarctic algae may be related to survival and defense mechanisms against elevated temperatures.