Structural and functional specificity of small heat shock protein HspB1 and HspB4, two cellular partners of HspB5: Role of the in vitro hetero-complex formation in chaperone activity

Biochimie ◽  
2012 ◽  
Vol 94 (4) ◽  
pp. 975-984 ◽  
Author(s):  
Fériel Skouri-Panet ◽  
Magalie Michiel ◽  
Céline Férard ◽  
Elodie Duprat ◽  
Stéphanie Finet
Keyword(s):  
Heat Shock ◽  
Complex Formation ◽  
Heat Shock Protein ◽  
Small Heat Shock Protein ◽  
Chaperone Activity ◽  
Functional Specificity

scholarly journals Acid-denatured small heat shock protein HdeA from Escherichia coli forms reversible fibrils with an atypical secondary structure

2018 ◽  
Vol 294 (5) ◽  
pp. 1590-1601 ◽  
Author(s):  
Shiori Miyawaki ◽  
Yumi Uemura ◽  
Kunihiro Hongo ◽  
Yasushi Kawata ◽  
Tomohiro Mizobata
Keyword(s):  
Escherichia Coli ◽  
Heat Shock ◽  
Secondary Structure ◽  
Heat Shock Protein ◽  
Molecular Chaperone ◽  
Protein Function ◽  
Amyloid Fibrils ◽  
Small Heat Shock Protein ◽  
Chaperone Activity

The periplasmic small heat shock protein HdeA from Escherichia coli is inactive under normal growth conditions (at pH 7) and activated only when E. coli cells are subjected to a sudden decrease in pH, converting HdeA into an acid-denatured active state. Here, using in vitro fibrillation assays, transmission EM, atomic-force microscopy, and CD analyses, we found that when HdeA is active as a molecular chaperone, it is also capable of forming inactive aggregates that, at first glance, resemble amyloid fibrils. We noted that the molecular chaperone activity of HdeA takes precedence over fibrillogenesis under acidic conditions, as the presence of denatured substrate protein was sufficient to suppress HdeA fibril formation. Further experiments suggested that the secondary structure of HdeA fibrils deviates somewhat from typical amyloid fibrils and contains α-helices. Strikingly, HdeA fibrils that formed at pH 2 were immediately resolubilized by a simple shift to pH 7 and from there could regain molecular chaperone activity upon a return to pH 1. HdeA, therefore, provides an unusual example of a “reversible” form of protein fibrillation with an atypical secondary structure composition. The competition between active assistance of denatured polypeptides (its “molecular chaperone” activity) and the formation of inactive fibrillary deposits (its “fibrillogenic” activity) provides a unique opportunity to probe the relationship among protein function, structure, and aggregation in detail.

scholarly journals Detrimental Role of Heat Shock Protein 60&70 and Toll-like Receptor 4 in Skeletal Muscle Ischaemia In Vitro

2013 ◽  
Vol 57 (5) ◽  
pp. 77S
Author(s):  
Ali Navi ◽  
Rebekah Yu ◽  
Xu Shi-Wen ◽  
Sidney Shaw ◽  
George Hamilton ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Heat Shock Protein 60 ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Muscle Ischaemia

scholarly journals Role of the Conserved SRLFDQFFG Region of α-Crystallin, a Small Heat Shock Protein

2003 ◽  
Vol 278 (51) ◽  
pp. 51159-51166 ◽  
Author(s):  
Saloni Yatin Pasta ◽  
Bakthisaran Raman ◽  
Tangirala Ramakrishna ◽  
Ch. Mohan Rao
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Small Heat Shock Protein

scholarly journals On the mechanism of chaperone activity of the small heat-shock protein ofMethanococcus jannaschii

2003 ◽  
Vol 100 (14) ◽  
pp. 8151-8155 ◽  
Author(s):  
Rosalind Kim ◽  
Luhua Lai ◽  
Hi-Hong Lee ◽  
Gang-Won Cheong ◽  
Kyeong Kyu Kim ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Small Heat Shock Protein ◽  
Chaperone Activity

scholarly journals Expression and Localization Patterns of a Small Heat Shock Protein that Interacts with the Helicase Domain of Cucumber Green Mottle Mosaic Virus

2019 ◽  
Vol 109 (9) ◽  
pp. 1648-1657
Author(s):  
Shanshan Liu ◽  
Lifeng Liu ◽  
Miguel A. Aranda ◽  
Bin Peng ◽  
Qinsheng Gu
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Mosaic Virus ◽  
Defense Mechanisms ◽  
Citrullus Lanatus ◽  
Small Heat Shock Protein ◽  
Helicase Domain ◽  
Rna Accumulation

Cucumber green mottle mosaic virus (CGMMV), a member of the genus Tobamovirus (family Virgaviridae), is an economically important virus that has detrimental effects on cucurbit crops worldwide. Understanding the interaction between host factors and CGMMV viral proteins will facilitate the design of new strategies for disease control. In this study, a yeast two-hybrid assay revealed that the CGMMV helicase (HEL) domain interacts with a Citrullus lanatus small heat shock protein (sHSP), and we verified this observation by performing in vitro GST pull-down and in vivo coimmunoprecipitation assays. Measurement of the levels of accumulated sHSP transcript revealed that sHSP is upregulated on initial CGMMV infection in both Nicotiana benthamiana and C. lanatus plants, although not in the systemically infected leaves. We also found that the subcellular localization of the sHSP was altered after CGMMV infection. To further validate the role of sHSP in CGMMV infection, we produced and assayed N. benthamiana transgenic plants with up- and down-regulated sHSP expression. Overexpression of sHSP inhibited viral RNA accumulation and retarded disease development, whereas sHSP silencing had no marked effect on CGMMV infection. Therefore, we postulate that the identified sHSP may be one of the factors modulating host defense mechanisms in response to CGMMV infection and that the HEL domain interaction may inhibit this sHSP function to promote viral infection.

Protective role of Mycobacterium leprae small heat-shock protein in heterologous hosts, Escherichia coli and Mycobacterium smegmatis, grown under stress

2013 ◽  
Vol 62 (7) ◽  
pp. 959-967 ◽  
Author(s):  
Jayapal Jeya Maheshwari ◽  
Kuppamuthu Dharmalingam
Keyword(s):  
Escherichia Coli ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Mycobacterium Smegmatis ◽  
Small Heat Shock Protein ◽  
Mycobacterium Leprae ◽  
Protective Role ◽  
Low Oxygen

The aim of this study is to examine the in vivo role of a small heat-shock protein (sHsp18) from Mycobacterium leprae in the survival of heterologous recombinant hosts carrying the gene encoding this protein under different environmental conditions that are normally encountered by M. leprae during its infection of the human host. Using an Escherichia coli system where shsp18 expression is controlled by its native promoter, we show that expression of shsp18 is induced under low oxygen tension, nutrient depletion and oxidative stress, all of which reflect the natural internal environment of the granulomas where the pathogen resides for long periods. We demonstrate the in vivo chaperone activity of sHsp18 through its ability to confer survival advantage to recombinant E. coli at heat-shock temperatures. Additional evidence for the protective role of sHsp18 was obtained when Mycobacterium smegmatis harbouring a copy of shsp18 was found to multiply better in human macrophages. Furthermore, the autokinase activity of sHsp18 protein demonstrated for what is believed to be the first time in this study implies that some of the functions of sHsp18 might be controlled by the phosphorylation state of this protein. Results from this study suggest that shsp18 might be one of the factors that facilitate the survival and persistence of M. leprae under stress and autophosphorylation of sHsp18 protein could be a mechanism used by this protein to sense changes in the external environment.

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