Related Experiment Video

Updated: Aug 15, 2026

Quantitative Approaches for Studying Cellular Structures and Organelle Morphology in Caenorhabditis elegans
08:47

Quantitative Approaches for Studying Cellular Structures and Organelle Morphology in Caenorhabditis elegans

Published on: July 5, 2019

The dynamin-related GTPase, Dnm1p, controls mitochondrial morphology in yeast

D Otsuga1, B R Keegan, E Brisch

  • 1Department of Biology, University of Utah, Salt Lake City, Utah 84112, USA.

The Journal of Cell Biology
|October 24, 1998
PubMed

Insights

The Saccharomyces cerevisiae Dnm1 protein is crucial for maintaining mitochondrial shape and distribution. This dynamin-related GTPase ensures the tubular mitochondrial network remains spread throughout yeast cells.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Genetics

Background:

  • The Saccharomyces cerevisiae Dnm1 protein shares structural similarities with dynamin, a GTPase vital for endocytosis.
  • Mitochondrial morphology and distribution are critical for cellular function.

Purpose of the Study:

  • To investigate the role of Saccharomyces cerevisiae Dnm1 protein in maintaining mitochondrial morphology and distribution.
  • To elucidate the function of Dnm1p in yeast cells.

Main Methods:

  • Gene disruption of DNM1 and analysis of mitochondrial morphology.
  • Site-directed mutagenesis of the predicted GTP-binding domain of Dnm1.
  • Indirect immunofluorescence microscopy to determine Dnm1p localization.
  • Cell fractionation and co-sedimentation assays to assess Dnm1p association with mitochondria.

Main Results:

  • Disruption of the DNM1 gene leads to the collapse of the tubular mitochondrial network to one side of the cell.
  • Mutations in the GTP-binding domain of Dnm1 impair its function and cause dominant mitochondrial defects.
  • Dnm1p localizes to punctate structures at the cell cortex, colocalizing with mitochondria.
  • Dnm1p associates with mitochondrial membranes.

Conclusions:

  • Saccharomyces cerevisiae Dnm1 protein is essential for maintaining mitochondrial morphology and cortical distribution.
  • Dnm1p plays a novel role in regulating the mitochondrial network in yeast, distinct from its structural relation to dynamin.
  • The GTPase activity of Dnm1p is critical for its function in mitochondrial organization.

More Related Videos

Imaging and Quantifying Mitochondrial Morphology in C. elegans During Aging05:29

Imaging and Quantifying Mitochondrial Morphology in C. elegans During Aging

Published on: January 17, 2025

Assessment of Mitochondrial Fission/Fusion Dynamics in Kidney Proximal Tubular Cells06:14

Assessment of Mitochondrial Fission/Fusion Dynamics in Kidney Proximal Tubular Cells

Published on: November 14, 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...
The Movement of Organelles and Vesicles01:43

The Movement of Organelles and Vesicles

In eukaryotic cells,  cytoskeletal filaments such as actin, microtubules, and intermediate filaments form a mesh-like cytoskeletal network. These filaments serve as tracks for transporting cellular cargo. Specialized motor proteins use the chemical energy stored in adenosine triphosphate (ATP) for this transport. During interphase, microtubules are polarized, with the plus-end towards the cell periphery and the minus-end towards the cell center. Two microtubule-associated motor proteins,...
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,...
Energy to Drive Translocation01:37

Energy to Drive Translocation

Mitochondrial protein import is powered by two distinct energy sources: ATP hydrolysis and electrochemical potential across the inner membrane. Newly synthesized precursors are bound by cytosolic chaperones of the Hsp70 family, which guide them to the import receptors on the mitochondrial surface. Utilizing the energy of ATP hydrolysis, Hsp70 chaperones transfer these precursors to the TOM receptors on the mitochondrial outer membrane.
Generally, polypeptides are unfolded by two distinct...
Pinching-off of Coated Vesicles01:32

Pinching-off of Coated Vesicles

Vesicle budding is orchestrated by distinct cytosolic proteins such as adaptor proteins, coat proteins, and GTPases. To initiate vesicle budding, membrane-bending proteins containing crescent-shaped BAR domains bind to the lipid heads in the bilayer and distort the membrane to form a protein-coated vesicle bud. Adaptors proteins such as AP2 for clathrin-coated vesicles can nucleate on the deformed membrane. Finally, coat proteins such as clathrin or COPI and COPII assemble into a coat forming...