Supporting data for “Tubulin post-translational modifications orchestrate neuronal growth, regeneration and functions”

Microtubules comprising highly conserved α/β-tubulin heterodimers provide mechanical support for neuronal development and intracellular transport. Following translation, tubulins undergo multiple enzymatic modifications, which expand the functional spectrum of microtubules by modifying their structure or interactions with microtubule-associated proteins. Yet how these post-translational modifications (PTMs) regulate microtubule functions in neurons remains to be elucidated. Most tubulin PTM studies were conducted via removing putative enzymes, which can fulfil other functions besides PTM catalysis, and thus easily misinterpret PTM significance. In some cases, PTM site-specific mutations were introduced via plasmid overexpression or transgene integration, which tend to disrupt endogenous tubulin expression levels. These technical limitations add layers to the complexity of microtubule regulation.

To study how neuronal development and regeneration are dynamically controlled by tubulin PTMs, my PhD project extensively applied CRISPR/Cas9 gene editing technology in Caenorhabditis elegans. What functions tubulin PTMs fulfill could be faithfully revealed by direct manipulation of putative PTM loci and verified by knocking out putative enzymes. The response of C. elegans to gentle mechanical stimuli relies on six touch receptor neurons (TRNs) that extend long sensory neurites along body wall, especially two pairs of lateral TRNs called ALMs and PLMs. TRNs enjoy substantial quantities of large-diameter microtubules comprising two specific tubulin isotypes, α-tubulin MEC-12 and β-tubulin MEC-7, making them an ideal model for studying tubulin PTMs.