Regulation of MAP1S-dependent microtubule dynamics by tubulin arginylation. Tubulin arginylation can occur on E77 of ⍺-tubulin (indicated by yellow circles). Within the dimer, E77 occurs near the interdimer interface (left inset), and within the microtubule, E77 occurs between protofilaments on the luminal side (right inset). In the absence of this modification in Ate1^−/− cells, there is an increase in the amount of MAP1S associated with microtubules, which leads to increased microtubule stability and decreased microtubule dynamics. Created using http://BioRender.com.