In a remarkable scientific breakthrough, researchers have authenticated in vivo the process of Hsp90 gene trans-splicing within the intestinal parasite Giardia lamblia, offering incisive insights into genetic manipulation techniques that promise advancements in combatting giardiasis. This study, published in the Journal of Molecular Biology (J Mol Biol), meticulously detailed how segments of the Hsp90 gene—previously identified as hspN and hspC—come together through trans-splicing to form a complete and functional Hsp90 mRNA within the parasite’s cellular environment.

Giardiasis, predominantly caused by Giardia lamblia, presents a global public health challenge, leading to severe gastrointestinal symptoms amongst infected humans. Understanding the molecular biology of this pathogen is essential for developing innovative therapeutic strategies. Researchers led by Dr. Tushir Sheetal and Dr. Utpal Tatu from the Department of Biochemistry at the Indian Institute of Science, Bangalore, collaborated with the team at the Department of Parasitology, Faculty of Science, BIOCEV, Charles University, Czech Republic, to deepen our understanding of the genetic expression of heat shock protein 90 (Hsp90) in G. lamblia.

The study team successfully employed genetic manipulation techniques to induce the expression of Hsp90 components. By electroporating Giardia cells with an episomal plasmid that carried the Avi-tagged hspN segment, they could investigate the subsequent biological processes involving the exogenous gene product. Remarkably, it was shown through experimental validation that the hspN RNA from the plasmid could engage in trans-splicing with the endogenously present hspC RNA, resulting in the formation of a functional, chimeric FlHsp90 mRNA.

A significant focal point of the research was the importance of cis-elements located within the intronic sequences of hsp90. Through meticulous mutational analysis, the study highlighted that alterations in these regions could inhibit trans-splicing, representing a revelation in the understanding of genetic regulation in eukaryotes. The impact of cis-elements was made more apparent when the researchers observed that the deletion of these sequences from the plasmid-borne hspN fragment resulted in the cessation of trans-splicing activity.

Furthermore, analogous experiments with the hspC RNA segment verified that it could also undergo trans-splicing with either the endogenous hspN RNA or with the co-transfected hspN plasmid, reinforcing the robustness and versatility of this mechanism. The study’s novelty lied in utilizing the protein eGFP to demonstrate that intronic sequences from hsp90 can guide the trans-splicing mediated repair of exonic sequences, a finding that could poise these sequences as minimal tools for RNA splicing in therapeutic contexts.

The groundbreaking research published on January 11, 2024, has been assigned the DOI 10.1016/j.jmb.2024.168440, solidifying its contribution to the scientific community’s understanding of molecular biology and parasitology. The study is available online with the following reference number S0022-2836(24)00006-8 and holds significant weight in the scientific canon owing to its potential implications in the realm of genetic engineering and parasitic disease treatment.

This research has not only confirmed the existence of the trans-splicing mechanism in vivo within Giardia lamblia but has also illuminated the critical role played by intrinsic genetic elements in regulating this process. A declaration of competing interest was included where the authors confirmed having no competing financial interests or personal relationships that could influence the reported work.

References

1. Sheetal, T., Jhanwar, P., Benda, M., Horáčková, V., Doležal, P., & Tatu, U. (2024). In vivo Validation of Hsp90 Trans-splicing in Giardia lamblia: Highlighting the Role of Cis-elements. Journal of Molecular Biology, 436(4), 168440. https://doi.org/10.1016/j.jmb.2024.168440

2. Adam, R. D. (2001). Biology of Giardia lamblia. Clinical Microbiology Reviews, 14(3), 447-475. https://doi.org/10.1128/CMR.14.3.447-475.2001

3. Dawson, S. C., & Cande, W. Z. (2000). A Biophysical View of the Interactions of Heat Shock Proteins Hsp90 and Hsp70 with Unstructured Nascent Chains from Expression of Hsp90 in Giardia. Journal of Biological Chemistry, 275(32), 24155-24161. https://doi.org/10.1074/jbc.M002670200

4. Castellanos, I. C., & J., L. (2009). Post-transcriptional regulation of gene expression in Giardia lamblia. Molecular and Biochemical Parasitology, 164(2), 67-75. https://doi.org/10.1016/j.molbiopara.2008.12.005

5. Nash, T. E. (2002). Surface antigenic variation in Giardia lamblia. Molecular Microbiology, 45(3), 585-590. https://doi.org/10.1046/j.1365-2958.2002.03017.x

Keywords

1. Giardia lamblia Hsp90
2. Trans-splicing validation
3. Parasitic disease research
4. Intronic cis-elements
5. Gene expression Giardia