Lazarus... Holzbaur. Plos. Take 2 Flashcards Preview

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Flashcards in Lazarus... Holzbaur. Plos. Take 2 Deck (15):
1

Why is transport on microtubules particularly vulnerable to disruption in axons/

1. Cells are long-lived. 2. Axon tracks extend up to one meter.

2

What is the rate-limiting step of microtubule formation?

Nucleation of soluble tubulin catalyzed by gamma-TURC enriched at the centrosome.

3

MAPS

Microtubule associated proteins

4

+TIPS

A spatially specialized group of MAPS that are plus end tracking proteins

5

What is the main goal of this paper?

Investigate whether p150glued modifies microtubule dynamics and affects catastrophe

6

Arp1

Forms the base of the dynactin complex

7

Paclitaxel

Stabilizes microtubules

8

What are two constructs that were created for the purposes of this paper?

P150-NT – has the N-terminal, and the CAP-Gly domain, but no dimerization domain. P150-NT-GCN4 – has a dimerization domain, N terminal CAP-gly, and basic microtubule binding domains. GCN4 replaces the first coiled coil.

9

What does increased light scattering indicate?

Increased microtubule polymerization

10

TIRF Microscopy

Total internal reflection fluorescence microscopy. The main idea is to reduce background fluorescence so that there is a higher signal to noise ratio. Selectively excites fluorophores in a restricted region adjacent to the glass-H2O interface. Only penetrates 100 nm. Can be used to observe fluorescence of a single molecule.

11

Doublecortin

This molecule is encoded by the DCX gene. It is another neuronal MAP. It is also called lissencephalin-x. It is another protein whose absence leads to lissencephaly (in addition to lis1) and it is also involved in neuronal migration (I think).

12

Does addition of doublecortin lead to light scattering?

Yes; doublecortin leads to microtubule polymerization, which promotes light scattering

13

What is one way to measure microtubule polymerization?

Light scattering

14

What did this study find regarding light scattering for monomers of p150 versus dimers? (p150-NT versus p150-NT-GCN4?)

Dimers increased microtubule polymerization, measured by light scattering; monomers did not

15

Does p150 need EB1 to promote microtubule formation?

According to this paper, no; they are independent of each other.