Towards an atomic model of a beating ciliary axoneme

Area of Science:

• Structural biology
• Cell biology
• Biochemistry

Background:

• The axoneme is a complex protein assembly essential for motile cilia and eukaryotic flagella.
• It powers single-cell locomotion and generates fluid flow in mammalian tissues.
• Its ordered structure has long been a target for structural biologists.

Purpose of the Study:

• To review the unique structural features of the axoneme.
• To provide a framework for understanding cilia assembly and function.
• To connect axonemal structure to ciliary beating mechanisms and associated diseases.

Main Methods:

• Review of recent structural biology studies.
• Focus on single-particle cryo-electron microscopy (cryo-EM) data.
• Integration of structural information with functional and clinical data.

Main Results:

• High-resolution structures of key axonemal protein complexes have been determined using cryo-EM.
• These structures reveal intricate details of the axoneme's organization.
• Unique structural features are linked to cilia assembly and beating mechanisms.

Conclusions:

• Structural insights into the axoneme are crucial for understanding cilia function.
• The detailed architecture explains how cilia generate movement and flow.
• Understanding these structures can shed light on clinical conditions caused by impaired cilia motility.