Microtubule Buckling Dynamics in Living Cells

CARLA PALLAVICINI; VALERIA LEVI; NICOLÁS GONZALEZ BARDECI; BRUNO MORETTI; ENRIQUE CERDA; HERNAN GRECCO; LUCIANA BRUNO

Salto

Congreso; Latin American Crosstalk in Biophysics and Physiology; 2015

P { margin-bottom: 0.08in; direction: ltr; color: rgb(0, 0, 0); }P.western { font-family: "Times New Roman",serif; font-size: 12pt; }P.cjk { font-family: "Droid Sans Fallback"; font-size: 12pt; }P.ctl { font-family: "Lohit Hindi"; font-size: 12pt; }Thecytoskeleton is an interconnected network of polimeric proteins:actin, microtubules and intermediate filaments. It plays a relevantrole in eukaryotic cells, being involved in numerous cellularprocesses such as cellular migration and division and intracellulartransport as well as providing mechanical support for the cell.Microtubules, having a diameter of 25nm are capable of supportingmaximum compressive loads amongst cytoskeletal components. In livingcells, these proteins are subject to active forces in a complex mediathat is in constant remodelling. In this work we explorehow forces affect the shapes and dynamics of microtubules. In orderto achieve this wedeveloped an invivofilament tracking routine that is capable of recovering microtublepositions from confocal images[1].Xenopuslaevis melanophorecells were used, these can be stimulated hormonally to performdistinct transport regimes of certain organelles: melanosomes. Westudy microtubule lateral motion and are able to map this movementwithin cells. Also, in order to understand the role of the filamentsin organelle transport, we analyzed lateral motion for cellsstimulated with different hormones. Finally, we study the buckling ofmicrotubules under compressive forces present in living cells. Weasses the importance of the cellular environment and microtubulepolymerization and depolymerization capability. Basedon this data, we are developingatheoretical mechanical model to describe these buckling events.