Final answer:
An accessory protein that facilitates microtubule nucleation is a Microtubule-Associated Protein, such as tau protein. These proteins play key roles in cell shape maintenance, cellular transport, and mitosis, specifically by aiding in the attachment of spindle fibers to centromeres during cell division.
Step-by-step explanation:
An accessory protein that accelerates nucleation in microtubules is known as a Microtubule-Associated Protein (MAP). These proteins include various types, but a common example is tau protein. During cell division, accessory proteins such as the kinetochore help in the attachment of spindle fibers to the centromeres of chromosomes, facilitating their separation into daughter cells.
Microtubules themselves are composed of alpha and beta tubulin monomers and are essential for maintaining the cell's shape, as well as playing significant roles in cellular processes such as mitosis. Specialized structures called kinetochores attach to microtubules during cell division, ensuring proper segregation of chromosomes.
When studying the formation and stabilization of microtubules, it's important to consider the role of accessory proteins like MAPs. For instance, in neurons, tau protein associates with microtubules to stabilize them, but if tau becomes hyperphosphorylated, it can lead to the disassembly of microtubules, contributing to neurodegenerative diseases.