Tubulin Dynamics in Fox Lung Cells
The ends of microtubules are always in dynamic formation: addition or removal of tubulin proteins alters the length of the biopolymer. The rate of depolymerization is different for each end according to its polarity, and the side that grows the fastest is considered the positive end while the other, more stable terminus, is negative. The dynamic, fast-growing portion of the microtubule is composed of beta-tubulin projected out towards the membrane of the cell. The alpha-tubulins stabilize their structure toward the nucleus at the centriole located in the centrosome of the cell. In the digital videos presented above, normal Gray fox lung fibroblast cells (FoLu line) are expressing enhanced green fluorescent protein (EGFP) fused to tubulin.