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AKB: Biologische Physik

AKB 100: Poster Session I

AKB 100.38: Poster

Saturday, March 5, 2005, 16:45–18:45, Poster TU D

Mechanical properties of microtubules measured with SPT: the effect of molecular motors — •Francesco Pampaloni¹, Gianluca Lattanzi², Thomas Surrey¹, Erwin Frey³, Ernst H. K. Stelzer¹, and Ernst-Ludwig Florin⁴ — ¹EMBL Heidelberg - Cell Biology and Biophysics Programme - Heidelberg (Germany) — ²Physics Department - University of Bari (Italy) — ³Department of Theoretical Physics - Hahn-Meitner Institute - Berlin (Germany) — ⁴Center for Nonlinear Dynamics - University of Texas at Austin (USA)

Microtubules (MTs) play a fundamental role in imparting polarity to the cell, determining the plane of symmetry in cell division, and regulating cell movements and shape. With new powerful imaging and micromanipulation techniques and the application of theoretical models, the mechanical properties of single MTs and other cytoskeletal filaments can be analyzed in details. By using an assay based on single-particle tracking (SPT) and optical tweezers we recently discovered that the stiffness of MTs increases with their contour length; in other words, shorter MTs are more flexible than longer ones. This counter-intuitive property of MTs seems to have a fundamental role in the mechanics of the cell. There is also evidence that microtubules associated proteins (MAPs) can modulate the mechanical properties of MTs. In this talk, the effect of the kinesin-like protein Xklp1 on microtubules structure and mechanics is discussed. We also introduce a novel experimental approach aimed to elucidate the dynamic instability of MTs in three-dimension.