Final answer:
Gamma-tubulin initiates microtubule assembly by binding to the nucleating agent. It aligns the tubulin dimers for proper microtubule formation, playing a crucial role in the structural integrity and function of cells.
Step-by-step explanation:
Microtubules are essential components of the cytoskeleton found in all eukaryotic cells. They are made by polymerization of tubulin dimers, which are composed of two subunits: alpha-tubulin (α-tubulin) and beta-tubulin (ß-tubulin). During the initiation of microtubule assembly, gamma-tubulin (γ-tubulin), which is part of the microtubule organizing center (MTOC), provides a template that ensures the proper orientation of the microtubule protofilaments and attaches to the negative end, facilitating the addition of α-tubulin and ß-tubulin dimers to the positive end.
This action constitutes the nucleation phase of microtubule polymerization, which is crucial for the regulation of microtubule length and growth direction. Identifying gamma-tubulin's role highlights its importance in maintaining cellular architecture, intracellular transport, cell division, and other critical cellular processes that depend on the dynamic instability of microtubules.