Balancing Act: Tubulin Glutamylation and Microtubule Dynamics in Toxoplasma gondii

The success of the intracellular parasite in invading host cells relies on the apical complex, a specialized microtubule cytoskeleton structure associated with secretory organelles. The genome encodes three isoforms of both α- and β-tubulin, which undergo specific post-translational modifications (PTMs), altering the biochemical and biophysical proprieties of microtubules and modulating their interaction with associated proteins. Tubulin PTMs represent a powerful and evolutionarily conserved mechanism for generating tubulin diversity, forming a biochemical 'tubulin code' interpretable by microtubule-interacting factors. exhibits various tubulin PTMs, including α-tubulin acetylation, α-tubulin detyrosination, Δ5α-tubulin, Δ2α-tubulin, α- and β-tubulin polyglutamylation, and α- and β-tubulin methylation. Tubulin glutamylation emerges as a key player in microtubule remodeling in , regulating stability, dynamics, interaction with motor proteins, and severing enzymes. The balance of tubulin glutamylation is maintained through the coordinated action of polyglutamylases and deglutamylating enzymes. This work reviews and discusses current knowledge on tubulin glutamylation. Through in silico identification of protein orthologs, we update the recognition of putative proteins related to glutamylation, contributing to a deeper understanding of its role in biology.