Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BISC 372 > 1.3 Intermediate Filaments and Cell Polarity > Flashcards

1.3 Intermediate Filaments and Cell Polarity Flashcards

1
Q

Where are intermediate filaments found (2)?

A
  1. in vertebrates, nematodes and mollusks
  2. in cytoplasm of cells prone to mechanical stress
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Where are intermediate filaments not found?

A

animals that have rigid exoskeletons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Intermediate filaments do not use [ ], unlike actin and tubulin.

A

NTPs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Intermediate filaments (IF) are closely related to [ ].

A

nuclear lamins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the function of nuclear lamins?

A

form meshwork in nuclear envelope, and provide anchoring point for chromosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Nuclear lamins duplicated, and duplicates evolved into [ ].

A

rope-like IF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

IF are much more [ ] than actin and tubulin.

A

diverse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

IF proteins are encoded by [ ] different genes in humans, with functions specific to cell type.

A

70

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

All intermediate filaments are [ ].

A

elongated proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Conserved [ ] domain.

A

central alpha-helical domain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Parallel dimers used to form [ ].

A

anti-parallel tetramer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Tetramer lacks [ ] (both ends are the [ ]), unlike actin and tubulin.

A
  1. polarity
  2. same
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

[ ] stack laterally to form the filament. Held together through [ ] interactions.

A
  1. Eight
  2. hydrophobic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Intermediate filaments are very [ ].

A

flexible, stable and difficult to break

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the most diverse type of IF proteins?

A

keratin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

[ ] found in human genome. Approximately [ ] types of keratins in human epithelial cells. Approximately [ ] specific to hair and nail cells.

A
  1. 54
  2. 20
  3. 10
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Keratin filaments are [ ] of type 1 and type 2 keratin proteins.

A

equal proportion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the characteristics of type 1 and type 2 keratin?

A
  1. Type 1 keratin: acidic
  2. Type 2 keratin: neutral/basic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Type 1 and 2 form a [ ] used to make filaments.

A

heterodimer subunit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Keratin filament networks are cross-linked via [ ].

A

disulfide bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

[ ] makes the filament networks very strong, and survive death of the cell

A

cross-linking

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Keratin filaments impart strength on these specialized epithelial cells by anchoring intermediate filaments at the sites called [ ].

A

desmosomes and hemidesmosomes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What site type are desomosomes and hemidesmosomes?

A
  1. desmosomes: site of cell-cell contact
  2. site of cell-matrix contact
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is filaggrin?

A

accessory protein that bundles keratin filaments in outermost layers of the skin. Imparts greater toughness in the outer layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Individuals with filaggrin mutations are predisposed to [ ].

A

eczema

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is epidermolysis bullosa simplex?

A

caused by keratin mutations, slightest mechanical stress ruptures basal cells and produces blisters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Where are neurofilaments found?

A

in high concentration in axons of vertebrate neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What are the three types of neurofilaments?

A
  1. NF-L
  2. NF-M
  3. NF-H
29
Q

What is ALS (3)?

A
  • amyotrophic lateral sclerosis (ALS) also known as Loug Gehrig’s disease
  • associated with an abnormal assembly of neurofilaments in motor neuron cell bodies and axon
  • degeneration of axons leads to muscle atrophy and death
30
Q

In mouse model, ALS symptoms arise with [ ].

A

overexpression of NF-L or NF-H

31
Q

What are plakins?

A

linker proteins that connect intermediate filaments to other cytoskeletal structures

32
Q

What are plectin?

A

a type of plakin protein that links intermediate filaments to microtubules, actin filaments, and myosin filaments, and the plasma membrane

33
Q

Plectin and other plakins interact with [ ] that connect the cytoskeleton to the nuclear envelope.

A

protein complexes

34
Q

The protein complexes consist of [ ] proteins and [ ] proteins.

35
Q

Where are the SUN and KASH proteins located?

A
  1. SUN proteins are in the inner nuclear membrane
  2. KASH proteins are in the outer nuclear membrane
36
Q

SUN and KASH proteins bind to each other in the [ ].

A

lumen of nuclear envelope

37
Q

SUN and KASH connect the [ ] and [ ].

A

nuclear and cytoplasmic cytoskeletons

38
Q

SUN proteins bind to [ ].

A

nuclear lamina or chromosomes

39
Q

KASH proteins bind to [ ].

A

actin filaments (directly) and microtubules and IF (indirectly through motor proteins and plaskins, respectively)

40
Q

The linkage between cytoplasmic and nuclear cytoskeleton facilitates [ ] (3).

A
  1. chromosome movement during meiosis
  2. nuclear migration
  3. cytoskeletal organization
41
Q

What is cell polarity?

A

refers to the asymmetry of a cell’s structure and organization

42
Q

Cell polarity determines [ ] (3).

A
  1. direction of protein secretion
  2. signaling, orientation of cell division
  3. path of migration
43
Q

Cells polarize in response to [ ].

A

intracellular and extracellular cues

44
Q

Cytoskeleton acts to transduce [ ] and generate [ ].

A
  1. polarity signals
  2. cellular organization and behavior
45
Q

What are the Rho family of proteins (3)?

A
  1. Cdc42
  2. Rac
  3. Rho
46
Q

What are Rho family proteins?

A

monomeric GTPases that act as molecular switches. They cycle between active GTP-bound and inactive GDP-bound state

47
Q

[ ] determine the active state of the rho family of proteins.

A

regulatory proteins

48
Q

What are GEFs?

A

guanine nucleotide exchange factors. required to activate GTPases by GDP with GTP

49
Q

What are GAPs?

A

GTPase activating proteins. The inactivate GTPases by promoting hydrolysis of GTP

50
Q

What are GDIs?

A

guanine nucleotide dissociation inhibitors. Bind to GDP-bound forms and block GTP exchange by GEF proteins

51
Q

Active Cdc42 promotes [ ].

A

formation of filopodia on cell surface

52
Q

Rac promotes [ ].

A

actin polymerization at cell periphery, and sheet-like protrusions

53
Q

Rho promotes [ ].

A

bundling of myosin filaments in stress fibers of non-muscle cells

54
Q

[ ] is most highly conserved and often serves as a master regulatory of cell polarity.

55
Q

Clusters of Cdc42 transmits a signal that activates a protein called [ ].

56
Q

Formin causes the assembly of [ ].

A

actin filaments

57
Q

What is the function of PAR proteins?

A

generate anterior-posterior polarity

58
Q

Stationary cells [ ] polarity over the life of the cell.

59
Q

Cell migration requires [ ] polarity.

60
Q

Polarization also allows for protrusion of [ ], which is driven through [ ].

A
  1. leading edge
  2. nucleation of branced actin filaments
61
Q

Rac promotes the formation of [ ].

A

branched actin networks in lamellidodium

62
Q

Rho promotes [ ].

A

the formin-dependent nucleation and elongation of staight actin filaments

63
Q

Rock leads to [ ] and activates [ ].

A
  1. downstream inactivation of an actin-destabilizing protein
  2. myosin. Along with actin bundle formation, this increases contractility at the rear of the cell
64
Q

External signals can drive the process of cell migration via [ ].

A

chemotaxis

65
Q

What is chemotaxis?

A

the movement of a cell towards or away from a diffusible chemical source

66
Q

[ ] triggers Rho family proteins.

A

ligand binding at the receptor

67
Q

Neutrophils can detect [ ] which enables them to migrate towrads bacterial targets.

A

low concentrations of select diffusible peptides derived from bacterial proteins

BISC 372 (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions