microtubules

Microtubules are a main component of the cytoskeleton and play essential roles in a variety of cellular processes. These highly dynamic tubular structures are assembled from alpha- and beta-tubulin dimers to form a complex structural network of microtubules throughout the cytoplasm. This network provides a substrate for intracellular trafficking of vesicles, organelles, and other cargo and can also facilitate cell migration. Additionally, during cell division, microtubules make up the mitotic spindle and provide the mechanical force for chromosome segregation.

The cytoskeleton consists of three major types of cytosolic fibers: microtubules, microfilaments (actin filaments), and intermediate filaments. Tubulins are the microtubule building block and exist as globular dimeric proteins of alpha/beta chains. There are five distinct forms: alpha, beta, gamma, delta, and epsilon tubulin.