Related Experiment Video

Updated: Aug 13, 2026

An Improved Method to Isolate Mitochondrial Contact Sites
07:55

An Improved Method to Isolate Mitochondrial Contact Sites

Published on: June 16, 2023

Interaction between mitochondria and the actin cytoskeleton in budding yeast requires two integral mitochondrial

I Boldogh1, N Vojtov, S Karmon

  • 1Department of Anatomy and Cell Biology, Columbia University College of Physicians and Surgeons, New York, New York 10032, USA.

The Journal of Cell Biology
|June 25, 1998
PubMed

Insights

Mitochondria use actin cytoskeleton for movement during yeast cell division. Specific proteins, Mmm1p and Mdm10p, are crucial for docking mitochondrial actin-binding proteins to the organelle surface.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Biochemistry

Background:

  • Mitochondrial inheritance is vital for yeast cell viability.
  • The actin cytoskeleton facilitates mitochondrial transport to daughter cells.
  • Understanding the molecular mechanisms of mitochondria-actin interaction is key.

Purpose of the Study:

  • To identify proteins involved in yeast mitochondria-actin interactions.
  • To elucidate the role of specific mitochondrial proteins in actin-based motility.
  • To investigate the mechanism of mitochondrial docking to the actin cytoskeleton.

Main Methods:

  • Yeast genetics and cell biology techniques.
  • Biochemical assays including sedimentation and protein binding.
  • Analysis of mitochondrial motility in wild-type and mutant yeast strains.

Main Results:

  • Identified mitochondrial actin-binding proteins (mABP) and essential docking proteins Mmm1p and Mdm10p.
  • Demonstrated that Mmm1p and Mdm10p are integral outer membrane proteins required for mABP docking.
  • Showed that mutations in MMM1 or MDM10 abolish actin-dependent mitochondrial motility.

Conclusions:

  • Mmm1p and Mdm10p are essential for docking mABP to mitochondria.
  • These proteins couple mitochondria to the actin cytoskeleton for directed movement.
  • This interaction is critical for mitochondrial inheritance during yeast cell division.

More Related Videos

Mitochondrial Transformation in Baker's Yeast to Study Translation and Respiratory Complex Assembly09:53

Mitochondrial Transformation in Baker's Yeast to Study Translation and Respiratory Complex Assembly

Published on: June 7, 2024

Analysis of the Expression and Complexes Assembly of the Mitochondrial Respiratory Chain Proteins in the Fission Yeast Schizosaccharomyces pombe08:07

Analysis of the Expression and Complexes Assembly of the Mitochondrial Respiratory Chain Proteins in the Fission Yeast Schizosaccharomyces pombe

Published on: May 2, 2025

Related Concept Videos

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,...
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...
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...
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,...
Porin Insertion in the Outer Mitochondrial Membrane01:12

Porin Insertion in the Outer Mitochondrial Membrane

Porins are beta-barrel proteins translocated to the mitochondrial outer membrane through the TOM complex into the intermembrane space. Porin precursors bind TIM chaperones within the intermembrane space and are guided to the Sorting and Assembly Machinery complex or SAM complex on the outer mitochondrial membrane.
Three models describe the assembly of porins by the SAM complex and their insertion into the outer membrane. Model 1 suggests that porins are assembled outside the SAM channel as the...
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,...