A unique profilin-actin interface is important for malaria parasite motility.

Area of Science:

• Cell Biology
• Parasitology
• Biochemistry

Background:

• Profilin binds actin monomers, supplying them for filament formation in higher eukaryotes.
• Apicomplexan parasites, like Plasmodium berghei, have short, dynamic microfilaments and rely on profilin as a key monomer-sequestering protein.
• Apicomplexan profilins feature a unique β-hairpin motif absent in classical profilins.

Purpose of the Study:

• To investigate the role of the unique β-hairpin motif in apicomplexan profilin.
• To understand how profilin-actin interactions influence the gliding motility of Plasmodium berghei sporozoites.
• To explore the evolutionary implications of this unique protein interface for parasite locomotion.

Main Methods:

• Comparative analysis of two profilin mutants in Plasmodium berghei.
• In vivo force measurements on migrating sporozoites.
• Molecular dynamics simulations of profilin-actin interactions.

Main Results:

• The β-hairpin motif is critical for actin binding in apicomplexan profilins.
• Mutations affecting this motif impact the gliding motility of Plasmodium berghei sporozoites.
• Profilin-actin interaction dynamics fine-tune parasite gliding speed.

Conclusions:

• The unique profilin-actin interface in apicomplexans is an evolutionary adaptation for efficient gliding motility.
• This specialized interaction is vital for the rapid migration of malaria parasite vectors.
• Understanding this mechanism offers insights into apicomplexan biology and potential therapeutic targets.