Temperature-dependent conformational changes in Arabidopsis DEHYDRATION-RESPONSIVE ELEMENT BINDING PROTEIN 2A

Abstract

With the recent rise in global temperatures, understanding plant heat stress responses has become an urgent challenge. The DEHYDRATION-RESPONSIVE ELEMENT BINDING PROTEIN 2A (DREB2A) is one of the key transcription factors involved in plant responses to heat stress. Previous studies show that DREB2A degrades at 23 °C, while it accumulates at 37 °C in Arabidopsis, leading to heat-induced gene expression. However, the direct impact of temperature on DREB2A protein itself remains insufficiently understood. This study investigates the effect of temperature on the DREB2A protein by expressing recombinant DREB2A in Escherichia coli. Results demonstrate that DREB2A accumulates in E. coli at 37 °C but not at 23 °C, a pattern also observed in Arabidopsis, despite the differences between these organisms. Circular dichroism (CD) spectroscopy further revealed structural alterations in DREB2A between 23 °C and 37 °C, though specific details remain unclear. Taken together, these findings suggest that temperature-induced conformational changes occur in DREB2A between 23 °C and 37 °C, which may play a role in regulating its stability. This knowledge also indicates that 37 °C-induced stability is a contributing factor to successful purification of full-length recombinant DREB2A protein.