Expression of Heat Shock Protein 30 in Talaromyces marneffei during Phase Transition and in Response to Heat and Oxidative Stresses

Abstract

OBJECTIVE Heat shock protein 30 (Hsp30) has been identified as an immunogenic, yeast phase-specific protein in Talaromyces marneffei. The purpose of this study was to investigate how the hsp30 gene and Hsp30 protein are expressed during phase transition and in response to heat and oxidative stress exposure. METHODS Several sequence analysis tools were employed to predict hsp30 control elements and to determine the subcellular localization of Hsp30. In the phase transition experiment, Talaromyces marneffei conidia were cultivated at two different temperatures, 25 °C and 37 °C. Subsequently, stress response tests were conducted by subjecting the yeast cells to heat at 42 °C and by treating them with hydrogen peroxide. The levels of the hsp30 transcript and its protein were measured using real-time RT-PCR and western immunoblot analysis, respectively. RESULTS The sequence analysis revealed the presence of heat response element (HRE), stress responsive element (STRE), and xenobiotic responsive element (XRE), which are typically involved in regulating hsp genes. A web-based tool predicted that Hsp30 protein is localized in cytoplasm, nucleus, and cell membrane. The hsp30 transcript and Hsp30 protein were highly clearly detected in both yeast cells and conidia. Furthermore, the hsp30 transcript in yeast cells was upregulated following heat shock at 42° C and exposure to hydrogen peroxide. These findings indicate that Hsp30 plays a crucial role in assisting the yeast phase of T. marneffei to cope with heat and oxidative stresses. CONCLUSIONS Hsp30 is a protein specific to the conidial and yeast phases of T. marneffei. It likely performs a conserved chaperone function during yeast growth and plays a significant role in stress response by mitigating protein aggregation issues. KEYWORDS Talaromyces marneffei, heat shock protein 30, expression