The oligomeric plasticity of Hsp20 of Sulfolobus acidocaldarius protects environment-induced protein aggregation and membrane destabilization
| Autor: | Mousam Roy, Sayandeep Gupta, Somi Patranabis, Abhrajyoti Ghosh |
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| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
Sulfolobus acidocaldarius Hot Temperature Protein subunit Membrane lipids Archaeal Proteins Biophysics Protein aggregation Microscopy Atomic Force Biochemistry Fluorescence 03 medical and health sciences Membrane Lipids Protein Aggregates Biopolymers Membrane fluidity Scattering Radiation Amino Acid Sequence biology Chemistry Vesicle Circular Dichroism fungi Cell Membrane Cell Biology Hydrogen-Ion Concentration biology.organism_classification Sulfolobus Heat-Shock Proteins Small 030104 developmental biology Protein folding Hydrophobic and Hydrophilic Interactions Protein Binding |
| Zdroj: | Biochimica et biophysica acta. Biomembranes. 1860(12) |
| ISSN: | 1879-2642 |
| Popis: | Small heat shock proteins (sHsps) are a ubiquitous family of molecular chaperones that rescue misfolded proteins from irreversible aggregation during cellular stress. Many such sHsps exist as large polydisperse species in solution, and a rapid dynamic subunit exchange between oligomeric and dissociated forms modulates their function under a variety of stress conditions. Here, we investigated the structural and functional properties of Hsp20 from thermoacidophilic crenarchaeon Sulfolobus acidocaldarius. To provide a framework for investigating the structure-function relationship of Hsp20 and understanding its dynamic nature, we employed several biophysical and biochemical techniques. Our data suggested the existence of a ~24-mer of Hsp20 at room temperature (25 °C) and a higher oligomeric form at higher temperature (50 °C–70 °C) and lower pH (3.0–5.0). To our surprise, we identified a dimeric form of protein as the functional conformation in the presence of aggregating substrate proteins. The hydrophobic microenvironment mainly regulates the oligomeric plasticity of Hsp20, and it plays a key role in the protection of stress-induced protein aggregation. In Sulfolobus sp., Hsp20, despite being a non-secreted protein, has been reported to be present in secretory vesicles and it is still unclear whether it stabilizes substrate proteins or membrane lipids within the secreted vesicles. To address such an issue, we tested the ability of Hsp20 to interact with membrane lipids along with its ability to modulate membrane fluidity. Our data revealed that Hsp20 interacts with membrane lipids via a hydrophobic interaction and it lowers the propensity of in vitro phase transition of bacterial and archaeal lipids. |
| Databáze: | OpenAIRE |
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