Tubulin isotypes - functional insights from model organisms

The microtubule cytoskeleton is assembled from the alpha- and beta-tubulin subunits of the canonical tubulin heterodimer, which polymerizes into microtubules, and a small number of other family members, such as gamma-tubulin, with specialized functions. Overall, microtubule function involves the collective action of multiple alpha- and beta-tubulin isotypes. However, despite 40 years of awareness that most eukaryotes harbor multiple tubulin isotypes, their role in the microtubule cytoskeleton has remained relatively unclear. Various model organisms offer specific advantages for gaining insight into the role of tubulin isotypes. Whereas simple unicellular organisms such as yeast provide experimental tractability that can facilitate deeper access to mechanistic details, more complex organisms, such as the fruit fly, nematode and mouse, can be used to discern potential specialized functions of tissue- and structure-specific isotypes. Here, we review the role of alpha- and beta-tubulin isotypes in microtubule function and in associated tubulinopathies with an emphasis on the advances gained using model organisms. Overall, we argue that studying tubulin isotypes in a range of organisms can reveal the fundamental mechanisms by which they mediate microtubule function. It will also provide valuable perspectives on how these mechanisms underlie the functional and biological diversity of the cytoskeleton.

Automated summary

The microtubule cytoskeleton is built from alpha- and beta-tubulin subunits, along with other family members, and their role in microtubule function has been relatively unclear. Model organisms provide insights into the mechanisms of tubulin isotypes and their impact on the cytoskeleton's functional and biological diversity.