bims-tricox 2024-03-17 papers

Issue of 2024–03–17
three papers selected by
Yash Verma, University of Zurich

Methods Mol Biol. 2024 ;2778 201-220

Modular Assembly of Mitochondrial β-Barrel Proteins.

Rituparna Bhowmik, Fabian den Brave, Thomas Becker.

Mitochondrial β-barrel proteins fulfill crucial roles in the biogenesis and function of the cell organelle. They mediate the import and membrane insertion of proteins and transport of small metabolites and ions. All β-barrel proteins are made as precursors on cytosolic ribosomes and are imported into mitochondria. The β-barrel proteins fold and assemble with partner proteins in the outer membrane. The in vitro import of radiolabelled proteins into isolated mitochondria is a powerful tool to investigate the import of β-barrel proteins, the folding of the β-barrel proteins, and their assembly into protein complexes. Altogether, the in vitro import assay is a versatile and crucial assay to analyze the mechanisms of the biogenesis of mitochondrial β-barrel proteins.

Keywords: Blue native electrophoresis; Mitochondria; Protein import assay; SAM complex; TOM complex; β-barrel proteins

DOI: https://doi.org/10.1007/978-1-0716-3734-0_13

Methods Mol Biol. 2024 ;2778 185-200

MitoLuc: A Luminescence-Based Assay to Study Real-Time Protein Import into Mitochondria.

Holly C Ford, Ian Collinson.

All but a few mitochondrial proteins are translated into the cytosol and imported in via complicated and varied pathways. These processes occur over short time frames and, as such, are difficult to monitor with classical approaches such as Western blotting or autoradiography that require sample collection at discrete time points. The development of an assay based on a split version of the small luciferase-Mitoluc-has allowed us to monitor the import of proteins into mitochondria in high resolution and real time (Pereira et al., J Mol Biol 431:1689-1699, 2019). Luminescence measurements are acquired using a plate reader in the order of seconds. This allows scores of experiments to be conducted in parallel in a single multi-well plate and permits kinetic analysis yielding information about import mechanisms (Ford et al., Elife 11:e75426, 2022).

Keywords: Luminescence; MitoLuc; Mitochondria; NanoLuc; Protein import; Split-luciferase

DOI: https://doi.org/10.1007/978-1-0716-3734-0_12

Int J Mol Sci. 2024 Feb 29. pii: 2835. [Epub ahead of print]25(5):

Mitochondria at the Nanoscale: Physics Meets Biology-What Does It Mean for Medicine?

Lev Mourokh, Jonathan Friedman.

Mitochondria are commonly perceived as "cellular power plants". Intriguingly, power conversion is not their only function. In the first part of this paper, we review the role of mitochondria in the evolution of eukaryotic organisms and in the regulation of the human body, specifically focusing on cancer and autism in relation to mitochondrial dysfunction. In the second part, we overview our previous works, revealing the physical principles of operation for proton-pumping complexes in the inner mitochondrial membrane. Our proposed simple models reveal the physical mechanisms of energy exchange. They can be further expanded to answer open questions about mitochondrial functions and the medical treatment of diseases associated with mitochondrial disorders.

Keywords: autism spectrum disorder; carcinogenesis; equations of motion; mitochondria; proton-pumping complex; respiratory transport chain

DOI: https://doi.org/10.3390/ijms25052835