tubulin complex assembly

Definition

Target type: biologicalprocess

The aggregation and bonding together of alpha- and beta-tubulin to form a tubulin heterodimer. [GOC:mah]

Tubulin complex assembly is a crucial process in eukaryotic cells, involving the formation of microtubules, dynamic and versatile cytoskeletal filaments with diverse roles in cell division, intracellular transport, and cellular morphology. The process begins with the synthesis of α-tubulin and β-tubulin monomers, which are globular proteins. These monomers associate non-covalently to form heterodimers, the fundamental building blocks of microtubules. The formation of αβ-tubulin heterodimers is driven by hydrophobic interactions and a network of hydrogen bonds, ensuring the proper orientation and stability of the dimer.

The αβ-tubulin heterodimers then undergo a process called nucleation, where they assemble into short, unstable oligomers. This nucleation step is often the rate-limiting step in microtubule assembly and requires the presence of specific nucleation sites, such as centrosomes or microtubule-organizing centers (MTOCs) in the cell.

Once the nucleus is formed, further addition of αβ-tubulin heterodimers occurs at the plus end of the microtubule, which is the end where the α-tubulin subunit is exposed. This process is known as elongation, and it is driven by the hydrolysis of GTP bound to β-tubulin. GTP hydrolysis is essential for microtubule dynamics, as it promotes the depolymerization of the microtubule at its minus end, while maintaining the stability of the plus end.

As microtubules grow, they can interact with other cellular components, such as motor proteins, which use the microtubule as a track for transporting cargo throughout the cell. The dynamic instability of microtubules, which refers to the constant cycles of growth and shrinkage, is essential for these functions, allowing cells to adapt to changing needs and efficiently transport materials.

In addition to αβ-tubulin, microtubule assembly can be regulated by a variety of accessory proteins. These proteins can act as stabilizing or destabilizing factors, influencing the rate of microtubule assembly and disassembly. Some examples include microtubule-associated proteins (MAPs), which can bind to the microtubule lattice and regulate its stability and interactions with other cellular components.

Overall, tubulin complex assembly is a highly regulated and dynamic process essential for maintaining cell structure, division, and function. It involves a series of precisely orchestrated steps, from monomer synthesis to the formation of complex microtubule networks, all driven by a delicate balance of protein interactions and GTP hydrolysis.'
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Proteins (1)

Compounds (2)