Institut de Biologie StructuraleGrenoble / France


Microtubules & Microtubule-Associated Proteins

Team Members  : Emmanuelle Neumann, Guy Schoehn
Collaborations : VIC group IBS, D Skoufias Team, I Arnal (GIN) , M Vantard (GIN), A Andrieux (GIN)

The cytoplasm of eukaryotic cells contains an elaborated network of cytoskeletal elements, consisting of actin filaments and microtubules (MTs) engaged in a variety of cell functions. MTs are 25 nm in diameter and several microns long. They result of the auto-assemblage of tubulin heterodimers.
Since few years, in order to try to understand the key role played by MTs in cell morphogenesis, we are interested by several microtubule-associated proteins (MAPs).

MTs and TPPP-p25 - E. Neumann

In collaboration with people from the IBS ([D. Skoufias), we are interested by human proteins (TPPP-p25) identified as a new marker for Parkinson’s disease. These proteins target the microtubular network, inducing tubulin polymerization and MTs bundles.
Reference  :
S. DeBonis*, E. Neumann*, D. Skoufias. Self protein-protein interactions are involved in TPPP/p25 mediated microtubule bundling. Scientific Reports 2015 20 ;5 :13242.
* both authors contributed equally to this work

In collaboration with people from the GIN Grenoble (I. Arnal et M. Vantard*), we are interested since several years in Microtubules Associated Proteins (MAPs).
Since now we mainly studied plant MAPs : Arabidopsis MAPs (AtMAP65).

These proteins cross-link MTs by forming "bridges" between 2 adjacent MTs and associate to MTs bundles. The goal is to better understand their role in the MTs bundles organization and in the lattice of individual MT.

*previously PCV, IRTSV Grenoble
References :
*Gaillard, J., *Neumann, E., Van Damme D, Stoppin-Mellet V, Ebel C, Barbier E, Geelen D, Vantard M. (2008) « Microtubule polarity within bundles induced by plant AtMAP65-1 and AtMAP65-5 » * : both authors contribute equally to this work. Mol Biol Cell. 2008 Jul 30.
D. Portran, M. Zoccoler, J. Gaillard, V. Stoppin-Mellet, E. Neumann, I. Arnal, J. L. Martiel, and M. Vantard. (2013) MAP65/Ase1 promote microtubule flexibility. Mol Biol Cell 2013 24 : 1964-73.

More recently, we are implicated more strongly with I. Arnal who studies since several years the neuronal protein tau (implicated in Alzheimer disease ). Through this collaboration our goal is to study in the same time MTs and actin, by analyzing the role of two neuronal MAPs (tau and MAP6) in the coordinate organization of MTs and actin networks.