Journal of Glycobiology
Open Access

An Overview of Heat-Shock Proteins and its Functions in Cancer Glycobiology

Annika Bludau^{* *}Correspondence: Annika Bludau, Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, Germany, Email:

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Description

Heat-Shock Proteins (HSPs) are a group of highly conserved proteins that are present in all living organisms, from bacteria to humans. They play a crucial role in cellular homeostasis and in maintaining proper protein folding and function under various stress conditions, such as heat shock, oxidative stress, and inflammation.

The discovery of HSPs dates back to the 1960s when scientists observed that cells exposed to high temperatures showed an increase in the production of a group of proteins with molecular weights ranging from 60 to 110 kDa. These proteins were later identified as HSPs, which are classified into several families based on their molecular weight and function.

One of the well-studied families of HSPs is the HSP70 family, which is highly conserved across different species. HSP70 proteins are involved in a wide range of cellular processes, including protein folding and transport, and are essential for cell survival under stress conditions. They act as molecular chaperones, assisting in the folding and refolding of misfolded or denatured proteins, preventing protein aggregation, and promoting protein degradation.

Another important family of HSPs is the HSP90 family, which is involved in the stabilization and activation of a diverse set of client proteins, including many kinases and transcription factors. HSP90 also plays a critical role in regulating protein quality control pathways, such as the ubiquitin-proteasome system, and in modulating protein-protein interactions.

In addition to HSP70 and HSP90, other families of HSPs include the small HSPs, which are involved in the protection of cytoskeletal and other structural proteins under stress conditions, and the HSP60 family, which is involved in the folding of newly synthesized proteins in the mitochondrial matrix.

The expression of HSPs is regulated by a family of transcription factors known as Heat-Shock Factors (HSFs). Under stress conditions, HSFs become activated and translocate to the nucleus, where they bind to Heat-Shock Elements (HSEs) in the promoters of HSP genes, leading to the upregulation of HSP expression.

While HSPs are best known for their role in protecting cells from stress-induced protein damage, recent studies have shown that they also play a critical role in many other cellular processes, including immune regulation, cancer, and neurodegeneration.

In the immune system, HSPs act as danger signals, alerting the immune system to the presence of damaged or dying cells. They can also act as chaperones for antigens, promoting their presentation to the immune system and stimulating an immune response.

In cancer, HSPs have been shown to play a dual role, both promoting and inhibiting tumor growth. On one hand, HSPs can promote the survival and proliferation of cancer cells by stabilizing key oncogenic proteins and inhibiting apoptosis. On the other hand, HSPs can also act as targets for cancer immunotherapy, as they are overexpressed in many types of cancer cells and can stimulate an immune response.

In neurodegenerative diseases, such as Alzheimer's and Parkinson's disease, HSPs have been shown to play a protective role by promoting the clearance of misfolded proteins and preventing protein aggregation. However, in some cases, the expression of HSPs can also contribute to disease pathology by promoting inflammation and oxidative stress.

Conclusion

In conclusion, HSPs are a fascinating group of proteins with diverse functions that are critical for cellular homeostasis and stress response. While much remains to be discovered about the complex mechanisms by which HSPs regulate cellular processes, their potential as therapeutic targets for a range of diseases is becoming increasingly apparent.