Tweaking cartwheel and centriole symmetry by rational SAS-6 engineering
Talk 2 of the day, by Michel STEINMETZ from the Paul Scherrer Institute, Department of Chemistry and Biology, Laboratory of Biomolecular Research, Villigen CH, presents studies on how SAS-6 engineering effects Cartwheel and centriole symmetry
- In most species newly formed centrioles are organized around a 9-fold symmetric ‘cartwheel’ structure established by protein SAS-6
- They challenged the Scaffold model, that postulates cartwheel is formed first and dictates the assembly of 9 fold symmetric microtubule wall
- To do that experiments were performed to challenge this master role of the cartwheel by mutating SAS-6 to change cartwheel symmetry
- The oligomers formed by various SAS-6 mutants were characterized in vitro using a combination of biophysical and structural methods, and the impact on symmetry changing mutations on cartwheels was assessed in Chlamydomonas and human cells
- Independent model: Their findings reveal that cartwheel and microtubule wall operate in an independent manner to establish the 9-fold symmetric architecture of centrioles.