Thread by @Phernael

Delighted to share with you a new exciting #publication in @eLife from my previous lab at @CIB_CSIC that finally came out today.
This paper challenges the previously accepted model of how #microtubules / #tubulin #estructure changes upon #GTP #hydrolysis.
elifesciences.org/articles/50155

Microtubule #lattice #expansion has been previously thought to be consequence of GTP hydrolysis.
In this work, thank to the use of several #biochemical, #biophysical, and #bioinformatics techniques, showed that the #tubulindimmer expansion does not occur upon hydrolysis.

Microtubules shear-flow alignment and X-ray #fibrediffraction experiments together with #CryoEM data, and different use of analogues showed that #GDP-#BeF3 dimmers resembles the GTP bound state of tubulin, since BeF3 mimics the gamma-phosphate function of GTP, stabilising the MTs

However, GDP-BeF3 dimmers do not show axial lattice expansion, unlike the slowly hydrolysable #nucleotide #GMPCPP, a previously thought bona fide GTP-analogue that induces the expanded lattice. (Likely being result of the methylene group linking alpha and beta phosphates.)

One of the important ideas suggested by our results is that the axial compaction of the mammal microtubules lattice occurs between the states of GDP-Pi to Pi release, but not in the interphase between GTP and GDP-Pi.

This is important not only to understand the biophysics of the microtubule polymerisation/depolymerisation but because microtubules are still one of the targets for chemotherapy. Understanding these processes better could help us design better therapies in the future.

My contribution to this paper has been working with the BeF3 model in the biochemical experiments and TEM. Also, I feel very proud of having crystallised the BeF3 tubulin complex which was, at first, challenging.

rcsb.org/structure/6GZE

Although I am not a crystallographer, I introduced a key modification in the standardised protocol by adding the berilium fluoride in the cryo-preservation buffer since I suspected a rapid exchange between the "naïve" buffer and the binding site after the first negative crystal.

I want to thank everyone for their hard work. The seed of this work started many years ago and in the recent past, at least 3 years have been needed to do experiments and play tennis with the journal. Now that it is out is time to celebrate!

Special mention to Juan Estévez Gallego, a brilliant PhD student from @Fencingdocfer group, and to Dr. Marian A. Oliva the corresponding author of this paper.

The paper has got much more work than the one summarised here so please, do not hesitate to visit the article read it in more detail at:

elifesciences.org/articles/50155

Thanks for reading and sharing!

@threadreaderapp unroll