Mikrotubulushoz

Mikrotubulushoz is the Hungarian term associated with microtubules, which are fundamental filaments of the eukaryotic cytoskeleton. Microtubules are hollow cylinders about 25 nanometers in diameter, assembled from alpha- and beta-tubulin heterodimers into protofilaments that form a hollow tube. They polymerize and depolymerize dynamically, with nucleation occurring at microtubule organizing centers such as the centrosome in many animal cells.

The growth and shrinkage of microtubules are driven by GTP binding and hydrolysis on the tubulin subunits, a phenomenon known as dynamic instability. The plus end tends to grow more rapidly than the minus end, which is often anchored at the organizing center. Microtubules serve as tracks for motor proteins, including kinesins and dyneins, enabling the transport of vesicles, organelles, and other cellular cargo, as well as contributing to the organization and positioning of cellular components.

In mitosis and meiosis, microtubules form the spindle apparatus that aligns and separates chromosomes. They are also integral components of cilia and flagella, where stable microtubule doublets drive movement. Microtubule behavior is regulated by microtubule-associated proteins (MAPs) that stabilize or destabilize filaments, and by various post-translational modifications such as acetylation and detyrosination that influence interactions with motors and other proteins.

Clinically, drugs that target microtubules are widely used in cancer therapy; taxanes stabilize microtubules, while vinca alkaloids inhibit polymerization. Defects in microtubule dynamics are linked to neurodegenerative diseases and ciliopathies, highlighting the central role of mikrotubulushoz in cellular function.