scholarly journals α-Crystallin-Type Heat Shock Proteins: Socializing Minichaperones in the Context of a Multichaperone Network

2002 ◽  
Vol 66 (1) ◽  
pp. 64-93 ◽  
Author(s):  
Franz Narberhaus
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Protein Quality ◽  
Chaperone Activity ◽  
Close Cooperation ◽  
Irreversible Aggregation ◽  
Functional Features ◽  
Shock Proteins ◽  
And Function ◽  
Temperature Upshift

SUMMARY α-Crystallins were originally recognized as proteins contributing to the transparency of the mammalian eye lens. Subsequently, they have been found in many, but not all, members of the Archaea, Bacteria, and Eucarya. Most members of the diverse α-crystallin family have four common structural and functional features: (i) a small monomeric molecular mass between 12 and 43 kDa; (ii) the formation of large oligomeric complexes; (iii) the presence of a moderately conserved central region, the so-called α-crystallin domain; and (iv) molecular chaperone activity. Since α-crystallins are induced by a temperature upshift in many organisms, they are often referred to as small heat shock proteins (sHsps) or, more accurately, α-Hsps. α-Crystallins are integrated into a highly flexible and synergistic multichaperone network evolved to secure protein quality control in the cell. Their chaperone activity is limited to the binding of unfolding intermediates in order to protect them from irreversible aggregation. Productive release and refolding of captured proteins into the native state requires close cooperation with other cellular chaperones. In addition, α-Hsps seem to play an important role in membrane stabilization. The review compiles information on the abundance, sequence conservation, regulation, structure, and function of α-Hsps with an emphasis on the microbial members of this chaperone family.

scholarly journals Structure and Mechanism of Protein Stability Sensors: Chaperone Activity of Small Heat Shock Proteins

Biochemistry ◽  
2009 ◽  
Vol 48 (18) ◽  
pp. 3828-3837 ◽  
Author(s):  
Hassane S. Mchaourab ◽  
Jared A. Godar ◽  
Phoebe L. Stewart
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Protein Stability ◽  
Small Heat Shock Proteins ◽  
Chaperone Activity ◽  
Shock Proteins

scholarly journals Developmental Expression and Functions of the Small Heat Shock Proteins in Drosophila

2018 ◽  
Vol 19 (11) ◽  
pp. 3441 ◽  
Author(s):  
Teresa Jagla ◽  
Magda Dubińska-Magiera ◽  
Preethi Poovathumkadavil ◽  
Małgorzata Daczewska ◽  
Krzysztof Jagla
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Large Family ◽  
Active Role ◽  
Stress Conditions ◽  
Developmental Expression ◽  
Shsp Gene ◽  
Time Specific ◽  
Shock Proteins ◽  
And Function

Heat shock proteins (Hsps) form a large family of evolutionarily conserved molecular chaperones that help balance protein folding and protect cells from various stress conditions. However, there is growing evidence that Hsps may also play an active role in developmental processes. Here, we take the example of developmental expression and function of one class of Hsps characterized by low molecular weight, the small Hsps (sHsps). We discuss recent reports and genome-wide datasets that support vital sHsps functions in the developing nervous system, reproductive system, and muscles. This tissue- and time-specific sHsp expression is developmentally regulated, so that the enhancer sequence of an sHsp gene expressed in developing muscle, in addition to stress-inducible elements, also carries binding sites for myogenic regulatory factors. One possible reason for sHsp genes to switch on during development and in non-stress conditions is to protect vital developing organs from environmental insults.

scholarly journals Chaperoning STAT3/5 by Heat Shock Proteins: Interest of Their Targeting in Cancer Therapy

Cancers ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 21 ◽  
Author(s):  
Gaëtan Jego ◽  
François Hermetet ◽  
François Girodon ◽  
Carmen Garrido
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Cell Fate ◽  
Protein Quality ◽  
Immune Cell ◽  
Therapeutic Option ◽  
Specific Cell ◽  
Shock Proteins ◽  
Multicellular Organisms ◽  
Stat5 Transcription Factor

While cells from multicellular organisms are dependent upon exogenous signals for their survival, growth, and proliferation, commitment to a specific cell fate requires the correct folding and maturation of proteins, as well as the degradation of misfolded or aggregated proteins within the cell. This general control of protein quality involves the expression and the activity of molecular chaperones such as heat shock proteins (HSPs). HSPs, through their interaction with the STAT3/STAT5 transcription factor pathway, can be crucial both for the tumorigenic properties of cancer cells (cell proliferation, survival) and for the microenvironmental immune cell compartment (differentiation, activation, cytokine secretion) that contributes to immunosuppression, which, in turn, potentially promotes tumor progression. Understanding the contribution of chaperones such as HSP27, HSP70, HSP90, and HSP110 to the STAT3/5 signaling pathway has raised the possibility of targeting such HSPs to specifically restrain STAT3/5 oncogenic functions. In this review, we present how HSPs control STAT3 and STAT5 activation, and vice versa, how the STAT signaling pathways modulate HSP expression. We also discuss whether targeting HSPs is a valid therapeutic option and which HSP would be the best candidate for such a strategy.

scholarly journals Alzheimer Cells on Their Way to Derailment Show Selective Changes in Protein Quality Control Network

2020 ◽  
Vol 7 ◽  
Author(s):  
Margreet B. Koopman ◽  
Stefan G. D. Rüdiger
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Quality Control ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
Protein Quality ◽  
Protein Quality Control ◽  
Brain Regions ◽  
Control Network ◽  
Shock Proteins

Alzheimer’s Disease is driven by protein aggregation and is characterized by accumulation of Tau protein into neurofibrillary tangles. In healthy neurons the cellular protein quality control is successfully in charge of protein folding, which raises the question to which extent this control is disturbed in disease. Here, we describe that brain cells in Alzheimer’s Disease show very specific derailment of the protein quality control network. We performed a meta-analysis on the Alzheimer’s Disease Proteome database, which provides a quantitative assessment of disease-related proteome changes in six brain regions in comparison to age-matched controls. We noted that levels of all paralogs of the conserved Hsp90 chaperone family are reduced, while most other chaperones – or their regulatory co-chaperones - do not change in disease. The notable exception is a select group consisting of the stress inducible HSP70, its nucleotide exchange factor BAG3 – which links the Hsp70 system to autophagy - and neuronal small heat shock proteins, which are upregulated in disease. They are all members of a cascade controlled in the stress response, channeling proteins towards a pathway of chaperone assisted selective autophagy. Together, our analysis reveals that in an Alzheimer’s brain, with exception of Hsp90, the players of the protein quality control are still present in full strength, even in brain regions most severely affected in disease. The specific upregulation of small heat shock proteins and HSP70:BAG3, ubiquitous in all brain areas analyzed, may represent a last, unsuccessful attempt to advert cell death.

scholarly journals Heat Shock Proteins: Pathogenic Role in Atherosclerosis and Potential Therapeutic Implications

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Arman Kilic ◽  
Kaushik Mandal
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Vascular Endothelial Cell ◽  
Vascular Wall ◽  
Protective Role ◽  
Therapeutic Implications ◽  
Endothelial Cell Surface ◽  
Disease States ◽  
Shock Proteins ◽  
And Function

Heat shock proteins (HSPs) are a highly conserved group of proteins that are constitutively expressed and function as molecular chaperones, aiding in protein folding and preventing the accumulation of misfolded proteins. In the arterial wall, HSPs have a protective role under normal physiologic conditions. In disease states, however, HSPs expressed on the vascular endothelial cell surface can act as targets for detrimental autoimmunity due to their highly conserved sequences. Developing therapeutic strategies for atherosclerosis based on HSPs is challenged by the need to balance such physiologic and pathologic roles of these proteins. This paper summarizes the role of HSPs in normal vascular wall processes as well as in the development and progression of atherosclerosis. The potential implications of HSPs in clinical therapies for atherosclerosis are also discussed.

scholarly journals Structure and Function of Small Heat Shock Proteins from the Magnetotactic Bacterium Magnetospirillum magneticum AMB-1

2010 ◽  
Vol 67 (12) ◽  
pp. 698-704 ◽  
Author(s):  
Tetsuya ABE ◽  
Shinpei ITO ◽  
Naoya NISHI ◽  
Yoshihiro TSUKADA ◽  
Takuo YASUNAGA ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Small Heat Shock Proteins ◽  
Structure And Function ◽  
Magnetotactic Bacterium ◽  
Shock Proteins ◽  
And Function ◽  
Magnetospirillum Magneticum
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