Induction of stress proteins in anoxic and hyperthermicSpodoptera frugiperda cells

Abstract

In this study, we compare stress protein induction in anoxic and hyperthermicSpodoptera frugiperda cells. Anoxia transiently induces a cluster of heat shock proteins at 71 and 72 kDa. This is a subset of a larger group of stress proteins induced by heat shock. Several heat shock proteins reported in this study were previously undetected inS. frugiperda. With these additional proteins, the stress response of hyperthermicS. frugiperda closely resembles that ofDrosophila melanogaster. Prior investigations of stress protein induction during oxygen deprivation focused on mammalian cells. In sharp contrast to these cells, anoxicS. frugiperda cells neither induce glucose-regulated proteins nor suppress the heat shock family of 71/72 kDa proteins. These findings provide insight into the virtually unexplored area of stress protein induction in anoxic insect cells. In addition, they help to explain the effects of oxygen deprivation on heterologous protein yield from virally infected insect cells and to develop an oxygenregulated promoter for stably transformed insect cells.

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“…Protein fractions were concentrated via centrifugation with a Amicon Centriplus-10 (Amicon, Beverly, MA, USA) spun at 3000 rpm and 4 • C for upwards of 4 hr. The amount of TCA-precipitable radioactivity in the fractions was measured on a Beckman LS 6000SC scintillation counter (Fullerton, CA, USA) according to Hugler et al (1995). Between 45% and 94% of sample cpm was recovered after Amicon concentration.…”