Theory of Biomolecular Matter
Group leader: Prof. dr. Bela Mulder
The aim of our group is to understand the individual and collective behaviour of biomacromolecules and their aggregates, using the techniques of statistical mechanics and continuum mechanics. The work is inspired by concrete questions regarding the structure and function of actual components of the living cell, with a special focus on plant systems. read more >>
Recent highlight
In order to create an organ like the plant root from a single niche of pluripotent cells, plants must control the orientation of the division plane. If all divisions were transverse to the growth direction of the cell the organ would only growth lengthwise. In order to create a requisite number of cell layers the division plane of certain cells has to be longitudinal to the growth direction, in order to start a new parallel cell file. Together with experimental colleagues from Utrecht University, AMOLF researchers Eva Deinum, Simon Tindemans and Bela Mulder have elucidated the molecular mechanisms behind this orientational switch, by simulating the dynamics of the cortical microtubule network on the box-like cells in question. The dominant orientation of the microtubules determines the direction of the division plane. Studies on plants with mutant developmental patterns show that microtubule-associated proteins known as CLASPs are recruited to certain cell edges to facilitate the switch to a longitudinal orientation. If the activity of these proteins is incorporated in the simulations the switching indeed occurs in a robust manner.
Reference
P. Dhonukshe, D.A. Weits, A. Cruz-Ramirez, E.E. Deinum, S.H. Tindemans, K. Kakar, K. Prasad, A.P. Mähönen, C. Ambrose, M. Sasabe, G. Wachsmann, M. Luijten, T. Bennett, Y. Machida,R. Heidstra, G. Wasteneys, B.M. Mulder and B. Scheres
A PLETHORA-Auxin Transcription Module Controls Cell Division Plane Rotation through MAP65 and CLASP
Cell 149, 383–396 (2012)
Left: Absence of CLASP molecules on top and bottom edges does not allow microtubules to pass to the top and bottom cell faces, causing a transversely oriented microtubule array. Right: CLASPmolecules present at the and bottom edges facilitate passage of microtubules to the top and bottom cell faces. Leading to a longitudinally oriented microtubule array.
