Functional modification of the Chlamydomonas flagellar surface

Area of Science:

• Cell Biology
• Biochemistry
• Molecular Motors

Background:

• Chlamydomonas flagella display surface-associated force transduction.
• This motility is crucial for cell gliding and flagellar reorientation during mating.
• The study aims to identify flagellar proteins involved in adhesion and force transduction.

Purpose of the Study:

• To identify flagellar membrane glycoproteins acting as adhesive sites.
• To investigate the motor mechanism responsible for their translocation.
• To understand the role of these glycoproteins in flagellar motility and force transduction.

Main Methods:

• Utilized a specific rabbit IgG antibody against major flagellar glycoproteins.
• Employed pronase treatment to assess protein accessibility and function.
• Measured flagellar surface adhesiveness using polystyrene microsphere binding and translocation.
• Monitored antibody binding and cell agglutination.

Main Results:

• A specific antibody bound to and agglutinated cells via flagellar surfaces.
• Pronase treatment abolished flagellar motility-coupled adhesiveness.
• This loss of adhesiveness was reversible only with new protein synthesis.
• The faster-migrating high molecular weight glycoprotein was modified by pronase.
• Loss and recovery of antibody binding sites paralleled adhesiveness changes.

Conclusions:

• The faster-migrating major flagellar membrane glycoprotein likely mediates substrate interaction.
• This glycoprotein may couple adhesive sites to cytoskeletal components for force transduction.
• Flagellar surface glycoproteins are key players in motility-coupled force transduction.