Tubulin is the major constituent of microtubules, a cylinder consisting of laterally associated linear protofilaments composed of alpha- and beta-tubulin heterodimers. Microtubules grow by the addition of GTP-tubulin dimers to the microtubule end, where a stabilizing cap forms. Below the cap, tubulin dimers are in GDP-bound state, owing to GTPase activity of alpha-tubulin.

(UniProt, P08841)

A structural gene for β-tubulin. The mRNA first appears in the mesoderm during mid-embryogenesis at about the time when synthesis of β-tubulin begins and later disappears from the embryo when synthesis of the tubulin ends; the transcript reappears in the mesoderm during the pupal period (Raff et al., 1982; Natzle and McCarthy, 1984; Raff, 1984; Rudolph et al., 1987; Gasch et al., 1988; Kimble et al., 1989). During embryogenesis, βTub60C is only expressed in developing muscles; in pupae, it is expressed in adult muscles, imaginal discs, wing blades, optic lobes, ovaries and testes, but ceases (except in ovaries and testes) in adults. As compared to the tubulin encoded by βTub56D, the product of βTub60C is but a minor component of the total tubulin pool (Rudolph et al., 1987). When synthesis of the βTub60C tubulin begins in the embryo, α-Tubulin synthesis is increased (Raff et al., 1982).