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Assessment of Submitochondrial Protein Localization in Budding Yeast Saccharomyces cerevisiae
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Assessment of Submitochondrial Protein Localization in Budding Yeast Saccharomyces cerevisiae

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Morphology and protein composition of the mitochondrial nucleoids in yeast cells lacking Abf2p, a high mobility group

Isamu Miyakawa1, Miwako Kanayama, Yuka Fujita

  • 1Department of Biology, Faculty of Science, Yamaguchi University, Yamaguchi, Japan. miyakawa@yamaguchi-u.ac.jp

The Journal of General and Applied Microbiology
|February 2, 2011
PubMed

Insights

The major mitochondrial DNA-binding protein Abf2p (Abf2p) is crucial for yeast mitochondrial nucleoid (mt-nucleoid) morphology and transmission to daughter cells during log phase. Its absence impacts mt-nucleoid structure but not overall mitochondrial health.

Area of Science:

  • Mitochondrial biology
  • Yeast genetics
  • Molecular cell biology

Background:

  • Abf2p is a key protein involved in mitochondrial DNA binding in Saccharomyces cerevisiae.
  • Mitochondrial nucleoids (mt-nucleoids) are essential structures housing the mitochondrial genome.
  • Understanding Abf2p's function is vital for comprehending mt-nucleoid organization and inheritance.

Purpose of the Study:

  • To investigate the role of Abf2p in yeast mt-nucleoid morphology and function.
  • To analyze the impact of Abf2p deficiency on mt-nucleoid structure and segregation.
  • To compare mt-nucleoid protein composition in wild-type and Abf2p-deficient yeast cells.

Main Methods:

  • Utilized 4',6-diamidino-2-phenylindole (DAPI) staining for in vivo and in vitro visualization of mt-nucleoids.
  • Examined mt-nucleoid morphology in Abf2p-deficient (Δabf2) and wild-type yeast cells.
  • Assessed DAPI-fluorescence intensity and mitochondrial segregation in log-phase and stationary-phase cells.

Main Results:

  • Δabf2 cells exhibited diffuse, irregularly sized mt-nucleoids compared to wild-type cells' string-of-beads structure during log phase.
  • Reduced DAPI-fluorescence transmission to buds was observed in Δabf2 cells.
  • Mitochondrial morphology and segregation remained unaffected by Abf2p deficiency.
  • mt-nucleoid protein composition was similar between Δabf2 and wild-type cells in stationary phase, barring Abf2p.

Conclusions:

  • Abf2p significantly influences mt-nucleoid morphology and transmission to daughter cells during log phase in yeast.
  • The absence of Abf2p does not impair overall mitochondrial structure or segregation.
  • In stationary-phase cells, Abf2p deficiency has a minimal impact on the protein composition of mt-nucleoids.

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