8.A.173.  The Tubulin (Tubulin) Family

Tubulin is the major constituent of microtubules. It binds two moles of GTP, one at an exchangeable site on the beta chain and one at a non-exchangeable site on the alpha chain. It hydrolyzes GTP and interacts with several transport systems to regulate their activities. These include connexin 43, for which the gap junctional channel is regulated by tubulin (TC# 1.A.24.1.1), mitochondrial VDAC (1.B.8) where it also regulates metabolite and Ca²⁺ transport across the outer membrane (Rostovtseva et al. 2021), the K⁺ channel, TRESK-1 (TC# 1.A.1.8.1), and the dopamine transporter, DAT (TC# 2.A.22.1.3). There are many tubulin isoforms in any one organism.