Tubulinassociated

Tubulin-associated refers to proteins, complexes, and factors that interact with tubulin subunits or microtubules, thereby regulating microtubule dynamics, organization, and function. It encompasses microtubule-associated proteins (MAPs) and regulators that modulate polymerization, stability, nucleation, and interactions with motors and membranes. Tubulin can be free (alpha/beta tubulin heterodimers) or polymerized into microtubules; tubulin-associated proteins may bind free tubulin to influence dimer availability or bind microtubules to alter stability.

Roles and examples of tubulin-associated factors include a range of regulatory activities. Some proteins, like the stathmin family, bind tubulin dimers and sequester them, slowing polymerization. Others, such as XMAP215/TOG proteins, promote plus-end polymerization as processivity factors. Plus-end tracking proteins (+TIPs) like EB1 stabilize growing ends and recruit additional factors to microtubules. Severing enzymes such as katanin and spastin remodel microtubules by cutting filaments. Additional regulators include CLASP and CLIP-170, which modulate stability and interactions with membranes or motors. Enzymes that post-translationally modify tubulin, including tubulin tyrosine ligase and TTLL family enzymes that mediate tyrosination and glutamylation, are tubulin-associated in the sense that they alter tubulin properties and microtubule interactions. Chaperonins and tubulin-folding cofactors assist in tubulin biogenesis, ensuring proper folding and assembly.

In cells, tubulin-associated factors are essential for processes such as mitosis, neuronal development, intracellular transport, and ciliogenesis. Dysregulation of these interactions can contribute to cancer, neurodegenerative diseases, and developmental disorders.