MTOC

MTOC: Structural determination of microtubules organizing centres with Electron Tomography.

We closely collaborate with Dr. Sam Li and Prof. DA Agard's group (UCSF) in the structural elucidation of the microtubule organizing centre, an important and complex cellular organelle in eukaryotes that is linked to many human diseases. We have been involved in the determination and analysis of the structure of two eukaryotic MTOCs, the spindle pole body from yeast and the centriole/basal body from low plants, with electron tomography and subtomogram averaging. More specifically, we are involved in the development and application of image processing techniques for these works.

Structural determination of the centriole/basal body triplet from Chlamydomonas reinhardtii at ~4 nm resolution. Left: Densities associated to non-tubulin components highlighted in yellow whereas those contributed by tubulin in blue. Right: Model of the whole centriole/basal body showing the structural variation from the proximal to the distal end.

Microtubule nucleation machinery revealed by electron cryomicroscopy. Left (2 leftmost panels): Electron cryotomography of isolated spindle pole bodies from yeast and subsequent subtomogram averaging unveiled the in situ structure at 4 nm resolution (blue color), showing a ring of seven γTuSC subunits matching microtubule geometry. Right: Electron cryomicroscopy and iterative helical real-space reconstruction allowed determination of the in vitro γTuSC structure at high resolution (7 Å) and modelling in pseudo-atomic detail.

Relevant publications: