Defining functional domains within PF16: a central apparatus component required for flagellar motility

Area of Science:

• Cell biology
• Molecular biology
• Biochemistry

Background:

• Flagellar assembly and stability are crucial for motility.
• Mutations in the PF16 locus lead to paralyzed flagella and C1 microtubule absence in Chlamydomonas.
• PF16 protein, a member of the armadillo repeat family, is implicated in protein-protein interactions essential for C1 microtubule stability and flagellar function.

Purpose of the Study:

• To identify functional domains within the PF16 protein essential for its interactions.
• To characterize mutations at the PF16 locus and assess the role of specific domains in PF16 assembly and function.

Main Methods:

• Characterization of three mutations at the PF16 locus.
• Generation of deletion constructs of the PF16 gene.
• Testing the ability of deletion constructs to assemble and rescue motility in mutant pf16 cells.

Main Results:

• The first armadillo repeat of PF16 is necessary but not sufficient for protein assembly.
• The C-terminal 122 amino acids are not required for PF16 assembly or flagellar motility.
• The armadillo repeats of PF16 appear to function as a single unit for protein assembly.

Conclusions:

• The PF16 protein's armadillo repeats are critical for its assembly and stability.
• Understanding PF16 domains provides insights into flagellar central apparatus assembly and motility.
• This study elucidates the structural requirements for PF16 function in maintaining flagellar integrity.