Cytoskeleton II

Question 1

What binds to and stabilizes F-actin?

Answer 1

phalloidin

Question 1

The formation and contraction of the actomyosin ring drives the ____ and _____.

Answer 1

cleavage furrow; separation of daughter cells

Question 2

phalloidin

Answer 2

from death cap, binds to and stabilizes F-actin

Question 2

Activation of forming leads to _____ formation.

Answer 2

parallel actin bundle

Question 2

Myosin II, characteristic of _____, forms hetero-oligomers involving two heavy chains and two copies of each of two light chains.

Answer 2

striated muscle

Question 3

Lissencephaly

Answer 3

defect of brain development- no gyri- loss of n-cofilin

Question 4

_____ are filamentous polymers (~7 nm diameter) of actin monomers.

Answer 4

Microfilaments

Question 4

WASp

Answer 4

Wiskott-Aldrich syndrome protein

Question 5

_____ is observed in microvilli inclusion disease.

Answer 5

Loss of microvilli

Question 5

Rho activation causes the formation of ____ and ____.

Answer 5

stress fibers and focal adhesions

Question 7

In the presence of divalent cations and ATP, ____ assembles to form two stranded, helical filaments called ____.

Answer 7

G-actin; F-actin

Question 8

Activation of _____ leads to parallel actin bundle formation.

Answer 8

forming

Question 9

Myosin II, characteristic of striated muscle, forms hetero-oligomers involving ____ and two copies of each of ____.

Answer 9

two heavy chains; two light chains

Question 10

_____ are held together by the cross-linking proteins villin and fimbrin.

Answer 10

Actin bundles

Question 11

_____ are essential for amoeboid motility and muscle contraction.

Answer 11

Microfilaments

Question 12

_____ are critical for cell shape, movement, and polarity.

Answer 12

Microfilaments (MFs)

Question 13

N-cofilin is an ____.

Answer 13

actin filament depolymerizing factor

Question 14

____ stimulates Arp2/3 complexes.

Answer 14

WASp

Question 14

The formation and contraction of the ____ drives the cleavage furrow and separation of daughter cells.

Answer 14

actomyosin ring

Question 16

Microfilaments are essential for ______ and _____.

Answer 16

amoeboid motility; muscle contraction

Question 16

____ causes the formation of stress fibers and focal adhesions.

Answer 16

Rho activation

Question 18

Actin bundles are held together by the cross-linking proteins ____ and _____.

Answer 18

villin; fimbrin

Question 18

___ activates the formation of veils.

Answer 18

Rac

Question 18

____ activates the protrusion of fillopodia.

Answer 18

Cdc42

Question 20

_____, characteristic of striated muscle, forms hetero-oligomers involving two heavy chains and two copies of each of two light chains.

Answer 20

Myosin II

Question 22

Adherens junctions (AJs) proteins include ____ and _____.

Answer 22

cadherins and catenins

Question 23

Rac activates the formation of ____.

Answer 23

veils

Question 24

Wiskott-Aldrich syndrome (WAS)

Answer 24

x-linked immunodeficiency disease- WASp mutations

Question 26

Actin filament nucleation typically occurs at the ____.

Answer 26

plasma membrane

Question 27

Microfilaments (MFs) are critical for cell ____, _____, and _____.

Answer 27

shape; movement; polarity

Question 28

_____ is an actin filament depolymerizing factor.

Answer 28

N-cofilin

Question 30

Microfilaments are filamentous polymers (~7 nm diameter) of ____.

Answer 30

actin monomers

Question 31

The____ nucleates MF polymerization from the minus-end, allowing rapid elongation at the plus-end.

Answer 31

Arp2/3 complex

Question 32

Loss of microvilli is observed in _____.

Answer 32

microvilli inclusion disease

Question 35

_____ typically occurs at the plasma membrane.

Answer 35

Actin filament nucleation

Question 36

WASp stimulates _____.

Answer 36

Arp2/3 complexes

Question 37

What is epithelial-to-mesenchimal (EMT) transition?

Answer 37

internalization of cadherins and loss of cell-cell adhesions cancers

Question 38

The Arp2/3 complex nucleates MF polymerization from ____, allowing rapid elongation at _____.

Answer 38

the minus-end; the plus-end

Question 39

Cdc42 activates the protrusion of _____.

Answer 39

fillopodia

Question 40

In the presence of _____ and ____, G-actin assembles to form two stranded, helical filaments called F-actin.

Answer 40

divalent cations; ATP