Lysine Acetylation of Plant α-Tubulins: Scaling Up the Local Effect to Large System Transformations.

Abstract

Cell migration and motility, cell division, biogenesis and renewal of cell and tissue integrity, and the assembly and retention of cell or tissue architecture, to name but a few, represent increasingly vital processes at the cellular and whole-body levels. These biological processes are closely connected with the major structural transformations that cytoskeletal proteins undergo due to numerous post-translational modifications, including acetylation, tyrosynation, polyglutamylation, etc. We collected all the information on tubulin acetylation and data on related cellular manifestations. This work expands upon our previous investigations into PTM-associated microtubule remodeling by incorporating K60, K163, and K326 into our analysis. Subsequently, we applied the refined protocol to examine the impact of acetylation on the most prevalent tubulin isoforms: TBA1, TBA2, and TBA3. Our analysis identified three distinct patterns on the α-tubulin surface where interactions with neighboring subunits were altered upon acetylation. These findings suggest that acetylation significantly influences the inter-subunit interactions within the microtubule polymer. To assess the likelihood of rearrangement at each of the three acetylation sites (K60, K163, K326), we conducted a series of simulations involving nine tubulin molecules (representing a microtubule lattice). These simulations aimed to quantify the degree of dissociation susceptibility upon acetylation at each of these specific lysine residues while focusing on residues that serve as substrates for HDAC6 deacetylation in plants, K60, K163, and K326. In this study, we have gathered all relevant evidence for the impact of different acetylation points on the assembly and lifespan of microtubule organelles, using A. thaliana tubulins as a model object.