Exploring Tubulin Dynamics in Fibroblast Cells

Tubulin assembly produces microtubules of variable length, but with a precisely determined diameter close to 25 nanometers. The cylindrical walls are about 5 to 6 nanometers thick and the central channel, or lumen, is about 14 nanometers in diameter. The lumen appears empty in synthetic microtubules, but those in nerve cells often contain plugs of amorphous material. The wall of a microtubule may be thought of as being composed of parallel protofilaments, each a linear chain of tubulin subunits with alpha and beta-tubulins alternating along its length. In the digital videos presented above, African green monkey kidney fibroblast cells (CV-1 line) are expressing enhanced green fluorescent protein (EGFP) fused to human alpha-tubulin