The microtubules are intracellular dynamic polymers made up of evolutionarily conserved polymorphic alpha/beta-tubulin heterodimers and a large number of microtubule-associated proteins (MAPs). Microtubules have their intrinsic polarity; highly dynamic plus ends and less dynamic minus ends. Microtubules are required for vital processes in eukaryotic cells including mitosis, meiosis, maintenance of cell shape and intracellular transport. Microtubules are also necessary for movement of cells by means of flagella and cilia. In mammalian tissue culture cells microtubules have their minus ends anchored in microtubule organizing centers (MTOCs).The GTP (guanosintriphosphate) molecule is an essential for tubulin heterodimer to associate with other heterodimers to form microtubule. In vivo, microtubule dynamics vary considerably. Microtubule polymerization is reversible and a populations of microtubules in cells are on their minus ends either growing or shortening - this phenomenon is called dynamic instability of microtubules. The alpha-tubulin (relative molecular weight around 50 kDa) is globular protein that exists in cells as part of soluble alpha/beta-tubulin dimer or it is polymerized into microtubules. In different species it is coded by multiple tubulin genes that form tubulin classes (in human 6 genes).
alpha; alpha 3; Alpha-tubulin 2; alpha-tubulin 3; Alpha-tubulin 3C; alpha-tubulin 3C/D; Alpha-tubulin 3D; Alpha-tubulin 3E; B-ALPHA-1; brain-specific; Detyrosinated tubulin alpha-3C chain; Detyrosinated tubulin alpha-3D chain; Detyrosinated tubulin alpha-3E chain; hum-a-tub1; hum-a-tub2; LIS3; TUBA3; TUBA3C/E; tubulin; tubulin alpha-1A chain; Tubulin alpha-2 chain; tubulin alpha-3 chain; Tubulin alpha-3C chain; Tubulin alpha-3D chain; Tubulin alpha-3E chain; tubulin B-alpha-1; tubulin, alpha 2; tubulin, alpha 3c; tubulin, alpha 3e