Characterization of Septin Ultrastructure in Budding Yeast Using Electron Tomography

Area of Science:

• Cell Biology
• Molecular Biology
• Biophysics

Background:

• Septins are essential proteins for cytokinesis, the final stage of cell division.
• In budding yeast (Saccharomyces cerevisiae), septins localize to the bud neck during mitosis and interact with the plasma membrane.
• Previous in vitro studies demonstrated septins' ability to self-assemble into diverse filamentous structures.

Purpose of the Study:

• To describe the detailed procedures for characterizing the cellular ultrastructure of septins.
• To elucidate the three-dimensional organization of the septin cytoskeleton in dividing budding yeast at molecular resolution.

Main Methods:

• Utilized electron tomography of freeze-substituted sections.
• Employed cryo-electron tomography of frozen sections.
• Combined these techniques for high-resolution structural analysis.

Main Results:

• Determined the three-dimensional organization of the septin cytoskeleton.
• Provided molecular-level insights into septin structure within the cellular context.
• Visualized septin structures at the bud neck during mitosis.

Conclusions:

• The described methods enable detailed ultrastructural characterization of septin organization.
• This work provides a foundation for understanding septin function in cytokinesis.
• The study offers high-resolution insights into the septin cytoskeleton in vivo.