Cytoskeleton and Microtubules Lecture

These flashcards cover key terms and concepts related to microtubules, their structure, and function within the cytoskeleton.

Microtubules

Cylindrical structures made of tubulin that play a role in cell division and intracellular transport.

Dynamic Instability

The phenomenon where microtubules are always undergoing cycles of growth and shrinkage.

Tubulin

The protein building block of microtubules, consisting of alpha and beta subunits.

MTOC

Microtubule Organizing Center, where microtubules nucleate in the cell.

GTP Cap

A structure where GTP is bound to tubulin dimers at the growing end of a microtubule, promoting stability and growth.

Catastrophe

The transition of a microtubule from a state of growth to shrinkage, typically due to the depletion of GTP-tubulin.

Rescue

The transition of a microtubule from a state of shrinkage to growth, often when it encounters a GTP island.

Motor Proteins

Proteins such as dynein that move along microtubules carrying cellular cargo.

Gamma Tubulin

A member of the tubulin family that is essential for the nucleation of microtubules at the MTOC.

Cilia and Flagella

Cellular projections that are structurally similar, involved in cell movement.

MAPs (Microtubule Associated Proteins)

Proteins that interact with microtubules to regulate their stability and function.

Severing Enzymes

Enzymes that cut microtubules to regulate length and stability, such as katanin and spastin.

Protocubules

The chains of dimers that come together to form a microtubule.

Critical Concentration

The specific concentration of tubulin subunits at which the rate of microtubule growth equals the rate of shrinkage.

Augmin

A protein that can bind to existing microtubules and promote branching.

Hydrophobic Interactions

Forces that contribute to the stability of prototubules by promoting lateral associations.

Alpha Tubulin

One of the two subunits of tubulin that makes up microtubules, always found at the bottom of the dimer.

Beta Tubulin

The other subunit of tubulin that participates in the formation of microtubules and has a nucleotide binding site.

Search and Capture

The mechanism by which microtubules find and bind to chromosomes during cell division.

Nucleotide Binding Site

The specific site on tubulin where GTP or GDP attaches, influencing microtubule stability.

Dynein

A motor protein that moves towards the minus end of microtubules, essential for the movement of cilia and flagella.

Kinetocores

Protein structures on chromatids where microtubules attach during cell division.

Dynamic Behavior

Refers to the continual growth and shortening characteristics of microtubules.