Tubulin acetylation promotes penetrative capacity of cells undergoing radial intercalation

Post-translational modification of tubulin provides differential functions to microtubule networks. Here, we address the role of tubulin acetylation on the penetrative capacity of cells undergoing radial intercalation, which is the process by which cells move apically, insert between outer cells, and join an epithelium. There are opposing forces that regulate intercalation, namely, the restrictive forces of the epithelial barrier versus the penetrative forces of the intercalating cell. Positively and negatively modulating tubulin acetylation in intercalating cells alters the developmental timing such that cells with more acetylation penetrate faster. We find that intercalating cells preferentially penetrate higher-order vertices rather than the more prevalent tricellular vertices. Differential timing in the ability of cells to penetrate different vertices reveals that lower-order vertices represent more restrictive sites of insertion. We shift the accessibility of intercalating cells toward more restrictive junctions by increasing tubulin acetylation, and we provide a geometric-based mathematical model that describes our results.

Automated summary

Post-translational modification of tubulin plays a crucial role in regulating the penetrative capacity of cells undergoing radial intercalation. Modulating tubulin acetylation in intercalating cells alters developmental timing, with more acetylation leading to faster penetration. Cells preferentially penetrate higher-order vertices over tricellular vertices, indicating that lower-order vertices are more restrictive sites of insertion. Increasing tubulin acetylation shifts the accessibility of intercalating cells towards more restrictive junctions, as described by a geometric-based mathematical model.