Microtubules and Associated Proteins

Flashcards covering key concepts related to microtubules, their structure, function, dynamics, and associated proteins.

Microtubules

Hollow polymers made of 13 protofilaments, which are constructed from tubulin heterodimers.

Tubulin Heterodimer

A protein complex made of alpha (α) and beta (β) tubulin that forms the building blocks of microtubules.

GTPase Activity

The ability of beta tubulin to hydrolyze GTP, which regulates microtubule dynamics.

Protofilaments

Linear strands made of tubulin dimers that assemble into the structure of microtubules.

Dynamic Instability

The rapid switching between growth and shrinkage of microtubules, influenced by GTP and GDP-bound states.

Microtubule Organizing Center (MTOC)

Specialized structures that nucleate microtubules; the main MTOC in animal cells is the centrosome.

Kinesin

A motor protein that moves cargo toward the plus end of microtubules, crucial for anterograde transport.

Dynein

A motor protein that moves cargo toward the minus end of microtubules, responsible for retrograde transport.

Intermediate Filaments

Cytoskeletal components that provide structural support and are made of various protein polymers, distinct from actin and microtubules.

Motor Proteins

Proteins such as kinesins and dyneins that use ATP to move along microtubules, transporting cellular cargo.

MAP

Stabilize or destabilize microtubules

B tubulin

Positive end of microtubules that is hydrolyzed and exchanged

a tubulin

Minus end of microtubules and always bound to GTP