The emerging role of tubulin posttranslational modifications in cilia and ciliopathies

Tubulin posttranslational modifications (PTMs) add “tubulin code” to generate functional diversities of microtubules. Several types of tubulin PTMs accumulate on axonemes and basal bodies of cilia, including acetylation, glutamylation, glycylation and detyrosination. Among them, glutamylation, glycylation and detyrosination are mostly enriched in the B-tubules, whereas acetylation occurs on both Aand B-tubule of the microtubule doublets in a similar level. Recent studies indicate that tubulin PTMs are critical for the fine tuning of assembly/disassembly, maintenance, motility, and signaling of cilia. Dysregulated tubulin PTMs are strongly implicated in human disorders including ciliopathies and neuron degeneration. Here, we review the current understanding how tubulin PTMs regulate cilia formation and function, and their relevance to human health.