Related Experiment Video

Updated: Jul 2, 2025

Author Spotlight: Unveiling Mitochondrial Contact Sites and Architectural Insights
07:55

Author Spotlight: Unveiling Mitochondrial Contact Sites and Architectural Insights

Published on: June 16, 2023

1.4K

MIMAS is a new giant multifunctional player in the mitochondrial megacomplex playground

Kostas Tokatlidis1

  • 1School of Molecular Biosciences, University of Glasgow, Glasgow, UK.

Cell Reports
|February 22, 2024
PubMed

Insights

Researchers discovered a large protein complex in mitochondria that performs multiple roles. This megacomplex integrates mitochondrial biogenesis and metabolism, offering new insights into cellular energy production.

Area of Science:

  • Cell Biology
  • Mitochondrial Biology
  • Biochemistry

Background:

  • Mitochondria house multi-protein assemblies, typically performing single functions.
  • Understanding the regulation of mitochondrial function is crucial for cellular health.

Purpose of the Study:

  • To identify and characterize novel multi-functional protein complexes within the mitochondrial inner membrane.
  • To investigate the role of this complex in integrating mitochondrial biogenesis and metabolism.

Main Methods:

  • Cryo-electron microscopy to determine the structure of the megacomplex.
  • Biochemical assays to assess enzymatic activities and interaction partners.
  • Genetic manipulation to study the complex's function in vivo.

Main Results:

  • Identification of a 3-megadalton megacomplex in the mitochondrial inner membrane.
  • Demonstration that this complex integrates mitochondrial biogenesis and metabolic pathways.
  • Elucidation of the structural basis for the complex's multiple functions.

Conclusions:

  • The discovered megacomplex represents a novel functional hub in mitochondria.
  • This finding challenges the paradigm of single-function protein assemblies in mitochondria.
  • The complex's role in integrating biogenesis and metabolism provides new targets for therapeutic interventions.

More Related Videos

Rapid Isolation of the Mitoribosome from HEK Cells09:33

Rapid Isolation of the Mitoribosome from HEK Cells

Published on: October 4, 2018

11.0K
Author Spotlight: Unveiling Oxidative Phosphorylation System Dynamics and Mitochondrial Roles in Health and Disease05:45

Author Spotlight: Unveiling Oxidative Phosphorylation System Dynamics and Mitochondrial Roles in Health and Disease

Published on: May 3, 2024

1.1K

Related Concept Videos

The Supercomplexes in the Crista Membrane01:41

The Supercomplexes in the Crista Membrane

The mitochondrial cristae membrane is the primary site for the oxidative phosphorylation (OXPHOS) process of energy conversion mediated through respiratory complexes I to V. These complexes have been widely studied for decades, and it has been proven that they form supramolecular structures called respiratory supercomplexes (SC). These higher-order complexes may be crucial in maintaining the biochemical structure and improving the physiological activity of the individual complexes while...
2.5K
The Inner Mitochondrial Membrane01:28

The Inner Mitochondrial Membrane

The inner mitochondrial membrane is the primary site of ATP synthesis. The inner membrane domain that forms a smooth layer adjacent to the outer membrane is called the inner boundary membrane. This domain contains membrane transporters that drive metabolites in and out of the mitochondria.  In contrast, the inner membrane network that invaginates into the matrix space is called the cristae membrane. This domain accounts for principle mitochondrial function as it accommodates the protein...
3.4K
Mitochondrial Membranes01:45

Mitochondrial Membranes

A single mitochondrion is a bean-shaped organelle enclosed by a double-membrane system. The outer membrane of mitochondria is smooth and contains many porins - the integral membrane transporters. Porins enable free diffusion of ions and small uncharged molecules through the outer mitochondrial membrane but limit the transport of molecules larger than 5000 Daltons. Further, the outer mitochondrial membrane forms a unique structure called membrane contact sites with other subcellular organelles,...
10.3K
Translocation of Proteins into the Mitochondria01:19

Translocation of Proteins into the Mitochondria

Mitochondrial precursors are translocated to the internal subcompartments via independent mechanisms involving distinct protein machineries called translocases.
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
3.1K
Mitochondrial Protein Sorting01:39

Mitochondrial Protein Sorting

Mitochondria are double-membrane organelles of the eukaryotes involved in cellular metabolism, signaling, ATP synthesis, and programmed cell death.  Each of these processes requires specific proteins and enzymes that must be correctly sorted to the right mitochondrial subcompartment for the proper functioning of the organelle.
Most of these mitochondrial proteins are encoded by the nucleus and imported to the mitochondria as unfolded or loosely folded precursors. Mitochondrial precursors...
4.3K
Mitochondrial Precursor Proteins01:39

Mitochondrial Precursor Proteins

Mitochondrial precursors are partially unfolded or loosely folded polypeptide chains. Newly synthesized precursors are inhibited from spontaneously folding into their native conformation by the cytosolic chaperones, heat shock proteins 70 (Hsp70), and mitochondrial import stimulation factors (MSFs). Precursors bound to MSFs are guided to the TOM70-TOM37 receptors, while precursors bound to Hsp70  chaperones are targetted to TOM20-TOM22 receptor complexes.
Most of the mitochondrial...
2.6K