Cartwheel architecture of Trichonympha basal body.
Centrioles and basal bodies are essential for the formation of cilia, flagella, and centrosomes. They exhibit a characteristic ninefold symmetry imparted by a cartwheel thought to contain rings of SAS-6 proteins. We used cryoelectron tomography to investigate the architecture of the exceptionally long cartwheel of the flagellate Trichonympha. We found that the cartwheel is a stack of central rings that exhibit a vertical periodicity of 8.5 nanometers and is able to accommodate nine SAS-6 homodimers. The spokes that emanate from two such rings associate into a layer, with a vertical periodicity of 17 nanometers on the cartwheel margin. Thus, by using the power of biodiversity, we unveiled the architecture of the cartwheel at the root of the ninefold symmetry of centrioles and basal bodies.
Swiss Institute for Experimental Cancer Research, School of Life Sciences, Swiss Federal Institute of Technology, Lausanne, Switzerland.
Paul
P
Guichard
Ambroise
A
Desfosses
Aditi
A
Maheshwari
Virginie
V
Hachet
Carsten
C
Dietrich
Andreas
A
Brune
Takashi
T
Ishikawa
Carsten
C
Sachse
Pierre
P
Gönczy
D018797:Cell Cycle Proteins / Q000648:ultrastructure*; D020285:Cryoelectron Microscopy; D055032:Electron Microscope Tomography; D056952:Hypermastigia / Q000648:ultrastructure*; D015388:Organelles / Q000648:ultrastructure*
D018797:Cell Cycle Proteins