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Detection of the pH-dependent Activity of Escherichia coli Chaperone HdeB In Vitro and In Vivo
Published on: October 23, 2016
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Chaperone activity of large-size subunit catalases
Teresa Nava-Ramírez1, Wilhelm Hansberg1
1Departamento de Biología Celular y del Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, UNAM, Mexico.
Free Radical Biology & Medicine
|June 6, 2020
Summary
The C-terminal domain of large-size subunit catalases (LSCs) exhibits molecular chaperone activity, protecting proteins from denaturation. This chaperone function enhances cellular resistance to stress, particularly oxidative stress, in microorganisms.
Area of Science:
- Biochemistry
- Molecular Biology
- Cell Biology
Background:
- Large-size subunit catalases (LSCs) share structural similarities with known molecular chaperones like DJ-1 and Hsp31.
- LSCs are induced under stress and during cell differentiation in various microorganisms.
- Molecular chaperones play crucial roles in maintaining protein homeostasis and cellular resilience.
Purpose of the Study:
- To investigate the molecular chaperone activity of the C-terminal domain of LSCs.
- To determine the role of this domain in protecting proteins against denaturation.
- To assess the contribution of LSC chaperone activity to cellular stress resistance.
Main Methods:
- Assessing the ability of LSCs and their C-terminal domains to prevent heat, urea, or H2O2-induced denaturation of alcohol dehydrogenase.
- Evaluating the protective effect of catalases on already denatured alcohol dehydrogenase.
- Testing the impact of catalase chaperone activity on the survival of E. coli under stress conditions.
Main Results:
- The C-terminal domain of LSCs, specifically in Catalase-3 (TDC3), demonstrated significant chaperone activity.
- LSCs and the TDC3 protected alcohol dehydrogenase from denaturation, while truncated versions (C3ΔTD, C63) or small-size subunit catalases (SSCs) did not.
- Catalase-3 and TDC3 enhanced E. coli survival under stress, unlike C3ΔTD.
Conclusions:
- The C-terminal domain of LSCs possesses intrinsic molecular chaperone activity.
- This chaperone activity is crucial for cellular resistance to stress, including oxidative stress.
- The findings suggest a novel role for LSCs in cellular defense mechanisms and differentiation processes in filamentous fungi.
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