scholarly journals DNAJC9 integrates heat shock molecular chaperones into the histone chaperone network

2021 ◽  
Author(s):  
Colin M. Hammond ◽  
Hongyu Bao ◽  
Ivo A. Hendriks ◽  
Massimo Carraro ◽  
Alberto García-Nieto ◽  
...  
Keyword(s):  
Heat Shock ◽  
Molecular Chaperones ◽  
Histone Chaperone ◽  
Chaperone Network

The function of small heat-shock proteins and their implication in proteostasis

2016 ◽  
Vol 60 (2) ◽  
pp. 163-172 ◽  
Author(s):  
Annika Strauch ◽  
Martin Haslbeck
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Molecular Chaperones ◽  
Small Heat Shock Proteins ◽  
Independent Manner ◽  
Native Proteins ◽  
Domains Of Life ◽  
Broad Variety ◽  
Chaperone Network ◽  
Shock Proteins

All organisms rely on a conserved cellular machinery supporting and controlling the life cycle of proteins: the proteostasis network. Within this network, the main players that determine the fate of proteins are molecular chaperones, the ubiquitin–proteasome and the lysosome–autophagy systems. sHsps (small heat-shock proteins) represent one family of molecular chaperones found in all domains of life. They prevent irreversible aggregation of unfolded proteins and maintain proteostasis by stabilizing promiscuously a variety of non-native proteins in an ATP-independent manner. In the cellular chaperone network, sHsps act as the first line of defence and keep their substrates in a folding-competent state until they are refolded by downstream ATP-dependent chaperone systems. Besides this interaction with unfolding substrates upon stress, sHsps show a different mode of binding for specific clients which are also recognized under physiological conditions. In vertebrates, sHsps are especially needed to maintain the refractive index of the eye lens. Additionally, sHsps are linked to a broad variety of diseases such as myopathies and neuropathies. The most striking feature of sHsps is their ability to form dynamic ensembles of higher oligomers. The activity of sHsps is regulated by changes in the composition of the ensembles.

Principles of chaperone-mediated protein folding

1995 ◽  
Vol 348 (1323) ◽  
pp. 107-112 ◽  
Keyword(s):  
Protein Folding ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
Molecular Chaperones ◽  
Cellular Protein ◽  
Chaperone Proteins ◽  
Shock Proteins ◽  
Polypeptide Chains

The recent discovery of molecular chaperones and their functions has changed dramatically our view of the processes underlying the folding of proteins in vivo . Rather than folding spontaneously, most newly synthesized polypeptide chains seem to acquire their native conformations in a reaction mediated by chaperone proteins. Different classes of molecular chaperones, such as the members of the Hsp70 and Hsp60 families of heat-shock proteins, cooperate in a coordinated pathway of cellular protein folding.

Heat shock proteins: Molecular chaperones

1991 ◽  
Vol 19 (4) ◽  
pp. 166-172 ◽  
Author(s):  
Najma Ali ◽  
Naheed Banu
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Molecular Chaperones ◽  
Shock Proteins

scholarly journals Molecular chaperones and heat shock proteins in atherosclerosis

2012 ◽  
Vol 302 (3) ◽  
pp. H506-H514 ◽  
Author(s):  
Qingbo Xu ◽  
Bernhard Metzler ◽  
Marjan Jahangiri ◽  
Kaushik Mandal
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Molecular Chaperones ◽  
Mammalian Cells ◽  
Vessel Wall ◽  
Protective Role ◽  
Research Field ◽  
Stressed Cells ◽  
Shock Proteins ◽  
Prevention Of Atherosclerosis

In response to stress stimuli, mammalian cells activate an ancient signaling pathway leading to the transient expression of heat shock proteins (HSPs). HSPs are a family of proteins serving as molecular chaperones that prevent the formation of nonspecific protein aggregates and assist proteins in the acquisition of their native structures. Physiologically, HSPs play a protective role in the homeostasis of the vessel wall but have an impact on immunoinflammatory processes in pathological conditions involved in the development of atherosclerosis. For instance, some members of HSPs have been shown to have immunoregulatory properties and modification of innate and adaptive response to HSPs, and can protect the vessel wall from the disease. On the other hand, a high degree of sequence homology between microbial and mammalian HSPs, due to evolutionary conservation, carries a risk of misdirected autoimmunity against HSPs expressed on the stressed cells of vascular endothelium. Furthermore, HSPs and anti-HSP antibodies have been shown to elicit production of proinflammatory cytokines. Potential therapeutic use of HSP in prevention of atherosclerosis involves achieving optimal balance between protective and immunogenic effects of HSPs and in the progress of research on vaccination. In this review, we update the progress of studies on HSPs and the integrity of the vessel wall, discuss the mechanism by which HSPs exert their role in the disease development, and highlight the potential clinic translation in the research field.

scholarly journals RNAi-dependent heterochromatin assembly in fission yeast Schizosaccharomyces pombe requires heat-shock molecular chaperones Hsp90 and Mas5

2018 ◽  
Vol 11 (1) ◽  
Author(s):  
Kosuke Okazaki ◽  
Hiroaki Kato ◽  
Tetsushi Iida ◽  
Kaori Shinmyozu ◽  
Jun-ichi Nakayama ◽  
...  
Keyword(s):  
Heat Shock ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Molecular Chaperones ◽  
Heterochromatin Assembly

scholarly journals Disaggregases, molecular chaperones that resolubilize protein aggregates

2015 ◽  
Vol 87 (2 suppl) ◽  
pp. 1273-1292 ◽  
Author(s):  
David Z. Mokry ◽  
Josielle Abrahão ◽  
Carlos H.I. Ramos
Keyword(s):  
Heat Shock ◽  
Molecular Chaperones ◽  
Protein Function ◽  
Protein Aggregates ◽  
Cell Physiology ◽  
Biological Processes ◽  
Loss Of Function ◽  
Prion Propagation ◽  
Shock Proteins

The process of folding is a seminal event in the life of a protein, as it is essential for proper protein function and therefore cell physiology. Inappropriate folding, or misfolding, can not only lead to loss of function, but also to the formation of protein aggregates, an insoluble association of polypeptides that harm cell physiology, either by themselves or in the process of formation. Several biological processes have evolved to prevent and eliminate the existence of non-functional and amyloidogenic aggregates, as they are associated with several human pathologies. Molecular chaperones and heat shock proteins are specialized in controlling the quality of the proteins in the cell, specifically by aiding proper folding, and dissolution and clearance of already formed protein aggregates. The latter is a function of disaggregases, mainly represented by the ClpB/Hsp104 subfamily of molecular chaperones, that are ubiquitous in all organisms but, surprisingly, have no orthologs in the cytosol of metazoan cells. This review aims to describe the characteristics of disaggregases and to discuss the function of yeast Hsp104, a disaggregase that is also involved in prion propagation and inheritance.

scholarly journals Heat Shock Protein 90 as Therapeutic Target for CVDs and Heart Ageing

2022 ◽  
Vol 23 (2) ◽  
pp. 649
Author(s):  
Siarhei A. Dabravolski ◽  
Vasily N. Sukhorukov ◽  
Vladislav A. Kalmykov ◽  
Nikolay A. Orekhov ◽  
Andrey V. Grechko ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Molecular Chaperones ◽  
Heat Shock Protein 90 ◽  
Misfolded Proteins ◽  
Heart Cells ◽  
Metabolic Demand ◽  
Heart Protection ◽  
High Metabolic Demand

Cardiovascular diseases (CVDs) are the leading cause of death globally, representing approximately 32% of all deaths worldwide. Molecular chaperones are involved in heart protection against stresses and age-mediated accumulation of toxic misfolded proteins by regulation of the protein synthesis/degradation balance and refolding of misfolded proteins, thus supporting the high metabolic demand of the heart cells. Heat shock protein 90 (HSP90) is one of the main cardioprotective chaperones, represented by cytosolic HSP90a and HSP90b, mitochondrial TRAP1 and ER-localised Grp94 isoforms. Currently, the main way to study the functional role of HSPs is the application of HSP inhibitors, which could have a different way of action. In this review, we discussed the recently investigated role of HSP90 proteins in cardioprotection, atherosclerosis, CVDs development and the involvements of HSP90 clients in the activation of different molecular pathways and signalling mechanisms, related to heart ageing.

scholarly journals The sacrificial adaptor protein Skp functions to remove stalled substrates from the β-barrel assembly machine

2021 ◽  
Vol 119 (1) ◽  
pp. e2114997119
Author(s):  
Ashton N. Combs ◽  
Thomas J. Silhavy
Keyword(s):  
Molecular Chaperones ◽  
Outer Membrane Proteins ◽  
Adaptor Protein ◽  
Gram Negative Bacteria ◽  
Periplasmic Space ◽  
Timely Manner ◽  
Gram Negative ◽  
Bam Complex ◽  
Periplasmic Chaperone ◽  
Chaperone Network

The biogenesis of integral β-barrel outer membrane proteins (OMPs) in gram-negative bacteria requires transport by molecular chaperones across the aqueous periplasmic space. Owing in part to the extensive functional redundancy within the periplasmic chaperone network, specific roles for molecular chaperones in OMP quality control and assembly have remained largely elusive. Here, by deliberately perturbing the OMP assembly process through use of multiple folding-defective substrates, we have identified a role for the periplasmic chaperone Skp in ensuring efficient folding of OMPs by the β-barrel assembly machine (Bam) complex. We find that β-barrel substrates that fail to integrate into the membrane in a timely manner are removed from the Bam complex by Skp, thereby allowing for clearance of stalled Bam–OMP complexes. Following the displacement of OMPs from the assembly machinery, Skp subsequently serves as a sacrificial adaptor protein to directly facilitate the degradation of defective OMP substrates by the periplasmic protease DegP. We conclude that Skp acts to ensure efficient β-barrel folding by directly mediating the displacement and degradation of assembly-compromised OMP substrates from the Bam complex.

Role of plant heat-shock proteins and molecular chaperones in the abiotic stress response

2004 ◽  
Vol 9 (5) ◽  
pp. 244-252 ◽  
Author(s):  
Wangxia Wang ◽  
Basia Vinocur ◽  
Oded Shoseyov ◽  
Arie Altman
Keyword(s):  
Abiotic Stress ◽  
Stress Response ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
Molecular Chaperones ◽  
Abiotic Stress Response ◽  
Shock Proteins
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