Microtubules: Structure and Assembly

The process of breaking down a molecule by adding water.

The process of building up a molecule by removing water.

A protein that promotes the growth of microtubules.

A protein that promotes the breakdown of microtubules.

A protective cap at the end of a microtubule that helps maintain its stability.

Proteins that link adjacent microtubule doublets in cilia and flagella, preventing sliding and converting dynein movement into bending.

An arrangement of microtubules in cilia and flagella consisting of nine pairs of microtubules arranged in a ring around two central microtubules.

The basic structural unit of microtubules, consisting of two proteins: α-tubulin and β-tubulin.

A spiral arrangement of 13 protofilaments that forms the microtubule wall, and is the fundamental building block of microtubules.

Microtubules in cilia and flagella are composed of 9+2 arrangement, with each microtubule consisting of 13 protofilaments arranged in a ring-like structure.

The two central microtubules in the 9+2 arrangement of cilia and flagella, which are single microtubules.

Tubulin dimers in microtubules bind to guanosine triphosphate (GTP) for their assembly and stability.

A microtubule is composed of 13 protofilaments arranged in a ring-like structure.

Microtubules that are constantly assembling and disassembling, allowing for rapid changes in cell shape and movement.

Specialized structures that initiate microtubule assembly, acting as a starting point for new microtubule growth.

The process of forming new microtubules, initiated by the γ-TuRC.

The ability of microtubules to maintain their structure and resist disassembly.

A network of protein filaments that provides structural support and acts as a transport system within cells.

Structures within the cell that help organize the cytoskeleton, including microtubules. One example is the centrosome.

A structure within the cell that is responsible for organizing microtubules. It contains γ-TuRCs that initiate microtubule nucleation.

The protein subunit that forms the building blocks of microtubules, allowing them to assemble and disassemble.

The process of separating protofilaments at microtubule ends, leading to shorter and more dynamic microtubules.

Microtubules play a key role in intracellular transport. They allow organelles, vesicles, and other cellular cargo to move along them.

The addition of tubulin-GTP dimers to a microtubule. This process results in the growth of the microtubule.

The breakdown of microtubules into tubulin monomers, caused by GTP hydrolysis. This process results in the shortening of the microtubule.

The relative abundance of tubulin-GTP dimers in the cytoplasm. High concentrations favor polymerization, while low concentrations favor depolymerization.

Proteins that bind to microtubules and regulate their stability. Destabilizing MAPs promote depolymerization, while stabilizing MAPs promote polymerization.

The conversion of GTP (guanosine triphosphate) to GDP (guanosine diphosphate) which is hydrolyzed on tubulin dimers once incorporated into microtubules. This process is important for microtubule dynamics.

The balance between microtubule polymerization and depolymerization is crucial for maintaining microtubule structure and function. It allows for dynamic remodeling and adaptation to changing cellular needs.

The rapid cycles of growth and shrinkage that microtubules undergo.

When a microtubule grows by adding tubulin-GTP subunits to its plus end.

When a microtubule shrinks by losing tubulin subunits from its plus end.

The plus end of a microtubule is where growth and shrinkage occur.

The minus end of a microtubule is where it is anchored to a microtubule organizing center (MTOC).

The process of breaking down microtubules by removing tubulin dimers.

A protein that binds to microtubules and moves cargo along them.

A motor protein that moves cargo towards the plus (+) end of a microtubule.

A motor protein that moves cargo towards the minus (-) end of a microtubule.

A structure within the centrosome composed of 9 triplets of microtubules arranged in a 9+0 pattern.

A phenomenon where tubulin dimers are added at the plus (+) end and removed at the minus (-) end of a microtubule, maintaining a constant length.

The addition of tubulin dimers to the plus (+) end of a microtubule, resulting in growth.

The loss of the GTP cap at the end of a microtubule, leading to depolymerization.

The return of the GTP cap at the end of a microtubule, leading to polymerization.

A protein that binds to microtubules and stabilizes them.

A protein that binds to microtubules and promotes their depolymerization.

The process of moving molecules or organelles within a cell.

The process of cell division, which involves the separation of chromosomes.

The process of positioning organelles within a cell.