Related Experiment Video

Updated: Jun 3, 2026

Specific Labeling of Mitochondrial Nucleoids for Time-lapse Structured Illumination Microscopy
07:53

Specific Labeling of Mitochondrial Nucleoids for Time-lapse Structured Illumination Microscopy

Published on: June 4, 2020

DNA packaging proteins Glom and Glom2 coordinately organize the mitochondrial nucleoid of Physarum polycephalum

Kie Itoh1, Akiko Izumi, Toshiyuki Mori

  • 1Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Aichi 464-8602, Japan. kie@gene.nagoya-u.ac.jp

Mitochondrion
|March 17, 2011
PubMed

Insights

Researchers discovered Glom2, a new mitochondrial DNA (mtDNA)-packaging protein that works with Glom. Glom2 is crucial for maintaining mtDNA stability and organization within the mt-nucleoid.

Area of Science:

  • Mitochondrial biology
  • Molecular genetics
  • Biochemistry

Background:

  • Mitochondrial DNA (mtDNA) is essential for cellular respiration and is organized into structures called mt-nucleoids.
  • High-mobility group (HMG) proteins are known to be involved in DNA packaging.
  • Glom is a characterized mtDNA-packaging HMG protein in Physarum polycephalum.

Purpose of the Study:

  • To identify and characterize novel proteins involved in mtDNA packaging and organization.
  • To elucidate the functional relationship between Glom and other mt-nucleoid proteins.

Main Methods:

  • Protein identification and homology analysis (comparing Glom2 to yeast Mgm101).
  • In vitro binding assays to assess Glom2's interaction with mtDNA.
  • Synergistic activity assays with Glom for mtDNA condensation.
  • Gene silencing (down-regulation) experiments to study Glom2's in vivo function.
  • Analysis of mt-nucleoid morphology and mtDNA integrity.
  • Measurement of mtDNA-encoded gene mRNA accumulation.

Main Results:

  • A new mtDNA-packaging protein, Glom2, was identified, possessing a region homologous to yeast Mgm101.
  • Glom2 demonstrated the ability to bind to entire mtDNA molecules.
  • Glom2 exhibited synergistic activity with Glom in the in vitro condensation of mtDNA.
  • Down-regulation of Glom2 exacerbated mt-nucleoid morphological changes and mtDNA loss caused by Glom down-regulation.
  • Impaired mRNA accumulation of certain mtDNA-encoded genes was observed upon Glom2 down-regulation.

Conclusions:

  • Glom2 is a novel mtDNA-packaging protein that plays a significant role in mt-nucleoid organization.
  • Glom2 functions coordinately with Glom to maintain mtDNA stability and integrity.
  • Glom2 is essential for proper mt-nucleoid structure and the expression of mtDNA-encoded genes.

More Related Videos

Preparation of the Mgm101 Recombination Protein by MBP-based Tagging Strategy11:40

Preparation of the Mgm101 Recombination Protein by MBP-based Tagging Strategy

Published on: June 25, 2013

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

DNA Packaging00:58

DNA Packaging

Overview
DNA Packaging00:58

DNA Packaging

Overview
Chromatin Packaging01:32

Chromatin Packaging

Each human somatic cell contains 6 billion base pairs of DNA. Each base pair is 0.34 nm long, meaning each diploid cell contains a staggering 2 meters of DNA. This long DNA strand is packed inside a nucleus measuring only 10-20 microns in diameter with the help of specialized DNA-binding proteins called histones. Together they form a compact DNA-protein complex called chromatin. The chromatin is further compacted into higher-order structures. The highest level of compaction is achieved during...
Chromatin Packaging02:21

Chromatin Packaging

Each human somatic cell contains 6 billion base-pairs of DNA. Each base-pair is 0.34 nm long, which means that each diploid cell contains a staggering 2 meters of DNA. How is such a long DNA strand packed inside a nucleus measuring only 10 - 20 microns in diameter? 
The chromatin
In combination with specialized DNA binding protein called Histones, the DNA double helix forms a compact DNA: protein complex called chromatin. The chromatin itself is further compacted into higher-order structures.
Chromatin Packaging02:21

Chromatin Packaging

Each human somatic cell contains 6 billion base-pairs of DNA. Each base-pair is 0.34 nm long, which means that each diploid cell contains a staggering 2 meters of DNA. How is such a long DNA strand packed inside a nucleus measuring only 10 - 20 microns in diameter? 
The chromatin
In combination with specialized DNA binding protein called Histones, the DNA double helix forms a compact DNA: protein complex called chromatin. The chromatin itself is further compacted into higher-order structures.
Nucleoid01:24

Nucleoid

The nucleoid represents a structurally and functionally distinct region within prokaryotic cells, where the cell's DNA and associated proteins are housed. Unlike eukaryotic cells, prokaryotes lack a membrane-bound nucleus, and the nucleoid facilitates the organization and accessibility of the genetic material within this constraint. The DNA in most bacteria and archaea exists as a single, circular, double-stranded molecule that is highly compacted through supercoiling and interactions with...