Cell Bio Cytoskeleton Oct 17

MTOC is at which end of the MT?

(-) end

the MTOC contains what in the PCM

γ-tubulin

what is a seed to grow one new microtubule?

γ-TuRCs

a microtubule can grow directly from what?

a γ-tubulin template

does every cell in the body have a centrosome?

no

centrosome

a non-membrane-bound organelle found in animal cells that acts as a major microtubule-organizing center

centrioles

At the core of a centrosome are two centrioles, barrel-shaped structures made of nine sets of triplet microtubules. They are arranged perpendicularly to each other.

Pericentriolar material (PCM)

The centrioles are surrounded by a dense matrix of proteins called the pericentriolar material (PCM). This material is the site of new microtubule organization

functions of centrosome

- cell division

- microtubule organization

- cilia and flagella

- signal transduction

- disease

centrosome: cell division

During mitosis and meiosis, two centrosomes move to opposite poles of the cell, forming the bipolar spindle that separates chromosomes into two new daughter cells.

centrosome: microtubule organization

In non-dividing (interphase) cells, the centrosome organizes the cell's microtubule cytoskeleton.

centrosome: cilia and flagella

The mother centriole can mature into a basal body, which serves as the foundation for the formation of cilia and flagella.

centrosome: signal transduction

Centrosomes act as a nexus for important signaling pathways within the cell.

centrosome: disease

Centrosome instability, including having the wrong number or structure, is a hallmark of many cancers and other diseases.

GMPPCP is a non-hydrolyzable analog of GTP. if you polymerize microtubules from GMPPCP-tubulin hdereodimers what would you get?

more stable microtubules- mimics GTP cap

what do microtubules do in cells?

1. intracellular transport

2. structural support

3. organizing and shaping

analogy: microtubules are

roads (as long as 50μm)

analogy: motor proteins

trucks (force to move things)

analogy: organelles

cargo (packages)