Microtubule Buckling In Living Cells: A Computational And Experimental Analysis

PALLAVICINI, CARLA; WETZLER, DIANA E..; BARDECI, NICOLÁS GONZÁLEZ; BRUNO, LUCIANA; MONASTRA, ALEJANDRO; LEVI, VALERIA

Buenos Aires

Congreso; REUNIÓN CONJUNTA DE SOCIEDADES DE BIOCIENCIAS; 2017

SOCIEDADES DE BIOCIENCIAS ARGENTINAS

Microtubules (MTs) are filamentousbiopolymers involved in essential biological processes. They form keystructures in eukaryotic cells, thus it is very important to determine themechanisms involved in the formation and maintenance of the microtubulenetwork. Microtubulebucklings are transient andlocalized events commonly observed in living cells and characterized by a fastbending and its posterior relaxation. These events present characteristic sizesof a few microns and occur naturally in living cells. Active forces provided bymolecular motors have been indicated as responsible for most of these rapiddeformations. We explore the temporal evolution ofMT bucklings and observe that whilebuckling sizes and durations may vary amongst events, they can be described bythe same mechanical approach. In order to obtain an in-depth understanding ofthese episodes we performed numerical simulations of filaments in acytoplasmatic-like environment under different load scenarios and were able toassociate force application on the MTs with buckling amplitude progressions.Using a two color fluorescence technique we study the interplay betweentransported vesicles (fm4-64 endosomes) and MTs, in particular we focused oncases were the transported load seemingly caused a buckling event. With theseexperimental examples we drew a final feedback with the numerical simulationsand observed the buckling evolutions in cases were the force acts parallel operpendicular to the filament.Keywords: microtubules, buckling, active forces,living cells, fluorescence microscopy.