Cartwheels create symmetry and asymmetry

Area of Science:

• Cell biology
• Structural biology
• Biochemistry

Background:

• The centriole is a key organelle in eukaryotic cells, involved in cell division and organization.
• SAS-6 is a core component of the centriole cartwheel, essential for its structure and function.
• Understanding the molecular mechanisms of centriole assembly is crucial for cell biology.

Purpose of the Study:

• To determine the crystal structures of coiled-coil bundles from SAS-6.
• To investigate the interaction patterns of SAS-6 coiled-coil domains.
• To elucidate the molecular basis for centriole polarity establishment.

Main Methods:

• X-ray crystallography to obtain high-resolution structures of SAS-6 coiled-coil bundles.
• Structural analysis to identify key interaction interfaces and domains.
• Comparative analysis to understand domain interactions.

Main Results:

• The crystal structures revealed the detailed architecture of SAS-6 coiled-coil bundles.
• Two specific coiled-coil domains within SAS-6 were found to interact asymmetrically.
• This asymmetric interaction provides a molecular explanation for the polarity of centrioles.

Conclusions:

• The asymmetric interaction of SAS-6 coiled-coil domains is critical for establishing centriole polarity.
• This structural insight advances our understanding of centriole biogenesis and function.
• The findings open new avenues for investigating centriole-related disorders.