Lecture 14 - Cytoskeleton_ tubulin

Cytoskeleton

A network of filaments and tubules that maintain cell shape, organization, and support movement.

Microtubules

Polymers of the protein tubulin that form hollow tubes and have polarity.

Microfilaments

The thinnest filaments of the cytoskeleton, primarily composed of actin.

Intermediate filaments

Fibrous proteins providing structural support and stability; include desmin, keratin, and lamin.

Tubulin

A globular protein that is a building block of microtubules, existing as α-tubulin and β-tubulin.

Dynamic instability

The process by which microtubules undergo rapid cycles of elongation and shrinkage.

Nucleation

The initial process of microtubule formation where several tubulin molecules interact to form a seed.

Centrosome

The microtubule-organizing center (MTOC) in animal cells, typically composed of two centrioles.

Microtubule-organizing center (MTOC)

Cellular structure that initiates the assembly of microtubules.

Gamma-tubulin

A protein that plays a crucial role in microtubule nucleation at the MTOC.

Catastrophe

The transition from microtubule growth to shrinkage.

Rescue

The transition from microtubule shrinkage to growth.

Microtubule-associated proteins (MAPs)

Proteins that bind to microtubules to stabilize and regulate them.

Tau

A MAP associated with stabilization of microtubules, mutations of which can lead to neurodegenerative diseases.

Fluorescence microscopy

A technique used to visualize the dynamics of microtubules in live cells using fluorescent dyes.

Protofilament

A linear chain of tubulin dimers that stacks head to tail to form microtubules.