Bottom-Up In Vitro Methods to Assay the Ultrastructural Organization, Membrane Reshaping, and Curvature Sensitivity...

Area of Science:

• Cell Biology
• Biophysics
• Biochemistry

Background:

• Membrane remodeling is a fundamental cellular process involving plasma membranes and organelles.
• Septins are essential cytoskeletal proteins implicated in various cellular functions and diseases.
• Understanding septin-membrane interactions is key to deciphering their role in cellular processes.

Purpose of the Study:

• To investigate the interplay between septin ultrastructure and membrane remodeling at the micron scale.
• To elucidate how septins self-assemble at membranes and induce deformations.
• To determine septin sensitivity to membrane curvature.

Main Methods:

• Recombinant expression and purification of budding yeast and mammalian septin complexes.
• In vitro assays to analyze septin self-assembly at membranes.
• Utilizing supported lipid bilayers (SLBs), giant unilamellar vesicles (GUVs), large unilamellar vesicles (LUVs), and wavy substrates.

Main Results:

• Demonstrated septin self-assembly dynamics at membrane interfaces.
• Observed septin-induced membrane deformations under varying conditions.
• Quantified septin complex sensitivity to different membrane curvatures.

Conclusions:

• Septin self-assembly at membranes is a critical determinant of membrane remodeling.
• Septin organization and behavior are influenced by membrane physical properties, including curvature.
• This research provides insights into septin functions in health and disease.