C-Terminal Tail Polyglycylation and Polyglutamylation Alter Microtubule Mechanical Properties.

Microtubules are biopolymers that perform diverse cellular functions. Microtubule behavior regulation occurs in part through post-translational modification of both the α- and β-subunits of tubulin. One class of modifications is the heterogeneous addition of glycine and/or glutamate residues to the disordered C-terminal tails (CTTs) of tubulin.

Microtubule seams are not mechanically weak defects.

Microtubule rigidity is important for many cellular functions to support extended structures and rearrange materials within the cell. The arrangement of the tubulin dimers within the microtubule can be altered to affect the protofilament number and the lattice type. Prior electron microscopy measurements have shown that when polymerized in the presence of a high concentration of NaCl, microtubules were more likely to be ten protofilaments with altered intertubulin lattice types.

Modern methods to interrogate microtubule dynamics.

Microtubules are essential protein filaments required to organize and rearrange the interior of the cell. They must be stiff with mechanical integrity to support the structure of the cell. Yet, they must also be dynamic to enable rearrangements of the cell during cell division and development.

Mechanical properties of doubly stabilized microtubule filaments.

Microtubules are cytoskeletal filaments responsible for cell morphology and intracellular organization. Their dynamical and mechanical properties are regulated through the nucleotide state of the tubulin dimers and the binding of drugs and/or microtubule-associated proteins. Interestingly, microtubule-stabilizing factors have differential effects on microtubule mechanics, but whether stabilizers have cumulative effects on mechanics or whether one effect dominates another is not clear.