Microtubule minus end (MT minus end)

The microtubule minus end is the structurally distinct, slow-growing terminus of the microtubule polymer, typically characterized by the exposure of alpha-tubulin subunits. It serves as a critical regulatory hub for the assembly, stability, and spatial organization of the microtubule cytoskeleton. In many cells, the minus end is anchored and capped at the centrosome or other microtubule-organizing centers (MTOCs) by the gamma-tubulin ring complex (gamma-TuRC). In non-centrosomal arrays, such as those in neurons and epithelial cells, it is stabilized by a specialized class of minus-end tracking proteins (-TIPs), including the CAMSAP/Patronin family and the KANSL complex. Dysregulation of minus-end dynamics is heavily implicated in cancer progression, where it facilitates aberrant mitosis and centrosome clustering, as well as in neurodevelopmental and neurodegenerative disorders where cargo transport is impaired. Pharmacological targeting of the minus end involves specialized agents like Gatastatin, which specifically inhibits gamma-tubulin-mediated nucleation, and Pironetin, the only known microtubule-targeting agent that covalently binds alpha-tubulin to selectively block minus-end growth.

Other names

-TIP binding siteSlow-growing endAlpha-tubulin exposed endUncapped minus endMicrotubule negative end

Inhibition of microtubule nucleation via gamma-tubulin binding, suppression of minus-end growth by blocking alpha-tubulin polymerization, minus-end capping to prevent depolymerization, and disruption of centrosomal hyper-clustering.