Genomic organization and hypoxia inducible factor responsive regulation of teleost hsp90β gene during hypoxia stress

• Published in: Molecular biology reports Vol. 48; no. 9; pp. 6491 - 6501
• Main Authors: Barman, Hirak Kumar, Mohapatra, Shibani Dutta, Chakrapani, Vemulawada, Mondal, Subhajit, Murmu, Binita, Soren, Meenati Manjari, Patra, Kananbala, Swain, Rajeeb Kumar
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.09.2021; Springer Nature B.V
• Subjects: Animal Anatomy; Animal Biochemistry; Animals; Animals, Genetically Modified; Biomedical and Life Sciences; Cell Hypoxia - drug effects; Cell Hypoxia - genetics; Cell viability; Cobalt - pharmacology; Endoplasmic reticulum; Exons; Gene Deletion; Gene Expression; Gene Expression Regulation; Genes, Reporter; Genomics; Green Fluorescent Proteins - genetics; Green Fluorescent Proteins - metabolism; Heat shock proteins; HEK293 Cells; Histology; HSP90 Heat-Shock Proteins - genetics; HSP90 Heat-Shock Proteins - metabolism; Humans; Hypoxia; Hypoxia-Inducible Factor 1 - genetics; Introns; Life Sciences; Luciferases - genetics; Luciferases - metabolism; Morphology; Original Article; Physiology; Prokaryotes; Promoter Regions, Genetic; Regulatory sequences; TATA-binding protein; TATA-Box Binding Protein - metabolism; Transcription initiation; Transfection; Zebrafish - genetics; Zebrafish - metabolism; Zebrafish Proteins - metabolism; Promoter; gene; HIF induced expression; Hypoxic gene regulation; Channa striatus; hsp90β gene
• ISSN: 0301-4851; 1573-4978
• DOI: 10.1007/s11033-021-06657-7

Background The physiological significance of a large family of heat-shock proteins (HSPs), comprised of the cytosolic HSP90A and the endoplasmic reticulum component of HSPB, is evident in prokaryotes and eukaryotes. The HSP90A is believed to play critical roles in diverse physiological functions of cell viability and chromosomal stability including stress management. Heightened abundance of hsp90β transcript was documented in Channa striatus , a freshwater fish, which is capable of surviving within an extremely hypoxic environment. Methods and results To better understand the mechanism of hsp90β gene expression, we investigated its genomic organization. Eleven exons were identified, including a long upstream intron with a remarkable similarity with human, but not with chicken counterpart. Dual-luciferase assays identified promoter activity in a 1366 bp 5′-flanking segment beyond the transcription initiation site. Examination detected a minimal promoter of 754 bp containing a TATA-box, CAAT-enhancer in addition to providing clues regarding other enhancer and repressor elements. The driving capability of this minimal promoter was further validated by its binding ability with TATA-box binding protein and the generation of GFP expressing transgenic zebrafish (F 2 ). Further, deletion of an inverted HIF (hypoxia inducible factor) motif RCGTG (upstream of the TATA-box) dramatically reduced luciferase expression in a hypoxic environment (CoCl 2 treated cultivable cells) and was identified as a cis -acting HIF responsive element, necessary for the hypoxia-induced expression. Conclusions The results obtained herein provide an insight regarding how hsp90β gene expression is controlled by HIF responsive element in teleost both during hypoxia stress management and normal physiological functions, and suggested that the hsp90β gene promoter could be used as a potential candidate for generating ornamental and food-fish transgenics.