Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Microbiology Essay plans > small GTPases > Flashcards

small GTPases Flashcards

(43 cards)

Start Studying
1
Q

B tubulin is a

A

GTPase

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

alpha tubular is not a

A

GTPase

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

draw the Btubulun.GTP Btubulin.GDP exchange

A

what does it drive

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

Btubulun.GTP

A

straight filament

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

Btubulun.GDP

A

curved protofilament, due to GTP hydrolysis changing subunit conformation, weakens bonds in polymer

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

what is a GTP cap

A

adding GTP tubular at the + end which stabilises the protofilament, GDP is unstable

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

+ end

A

Btubulin bound to GTP which is more dynamic

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

loss of GTP cap =

A

release of tubular –>catastrophic shrinkage

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

most formins are activated by which GTPase

A

Rho-gtpase

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

nucleation of formins

A
  • FH1 and FH2 domains, work like swing arms, sequential working as a dimer with each FH adding an actin monomer
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

one of the FH monomers adds an actin the other is for

A

regulagulation proteins such as profilin

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

actin filaments are nucleated from

A

the plus end - straight filaments = forming

branched - arp 2/3 complex

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

thymosin and profilin

A

compete to bind G actin

  • profilin - favours ATP exchange on G actin - pro polymerisation
  • thymosin - sequesters actin away from filament - anti-polymerisation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

how do GPRCs transduce signals

A

they use an intermediate GTPase - a large GTPase and then a small gtpase

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

examples of small GTPases actions

A
  • initiation and elongation
  • SRP/SR family
  • tubular and cytoskeleton motor
  • small monomeric GTPase - Ras superfamily and Rho,Rac and Cdc42 rho gtpase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

GAP

A

GTPase activating protein

increases rate of GTP to GDP bound (inactivating GTPase)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

GEF

A

GTP/GEF exchange factor - activate the exchange

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

GDI

Study These Flashcards
A

GDI dissosciation inhibitor - decrease exchange of GTP for GDP

19
Q

Rho family and what do they do

Study These Flashcards
A

Rho, Rac and cdc42

relay signals from surface receptors to cytoskeleton and elsewhere

20
Q

central regulator of cell polarity

21
Q

once activates small GTPase activates target via

Study These Flashcards
A 
molecular switches - or directly 
small GTPase(2) or through a kinase
22
Q

localised Cdc42 activation by siganl

Study These Flashcards
A

recruitment effectors…

  • microtubule cytoskeleton
  • actin cytoskeleton
  • membrane trafficking
  • cell contacts
23
Q

cdc42 in golgi orientation and polarised actin cytoskeleton

Study These Flashcards
A

cdc42 - WASP - ARP2/3 - actin

24
Q

cdc42 in centrosome and polarised MTs

Study These Flashcards
A

cdc42 - PAK - stathmin - MTs

25
cdc42 in polarised secretion
cdc42 - par cplx - scribble cplx - membrane trafficking - polarised secretion
26
alternative cdc42 in MTs
cdc42 - parcplx - GSK3/APC - Mts
27
PAR proteins
- responsible for asymmetric positioning of the mitotic spindle and proteins and RNAs involved in the cells fate distinctions
28
mutation in PAR proteins
mitotic spindle and PARtitioning defective
29
Anterior PAR proteins
required to prevent PAR proteins from localising at the anterior and visa versa - POLARISED CELL
30
LBK1
is a PAR protein in humans - inactivate, cells are not polarised - found in the human colon - mutation - abnormal growth of lining in gut - polyps
31
Par3 - Par 6 - aPKC complex
epithelial cell polarity | - top/bottom, organelle distribution, membrane lipid composition
32
apical surface permeable to
H2O, faces the external milieu, SA can be increased
33
basolateral surface
impermeable, faces internal milieu and blood supply
34
PAR proteins with crumbs and scribble
- organise cell polarity | - influence each other by phosphorylation, localisation at cell junctions and bind/position small GTPases
35
tight junction localize
PAR + crumbs
36
scribble localizes
basolateral junction
37
Par proteins are
kinases which switch other proteins on/off | scaffolding factors - recruit and interact with other proteins regulating them
38
cdc42 controls
everything
39
RhoGTP - focal adhesion
RhoGTP - ROCK- coffin myosin - more stress fibres - focal adhesion RhoGTP - formin - more stress fibres - focal adhesion
40
RacGTP - lamellopodia
RacGTP - PAK - filamin myosin - less stress fibres - lamellopodia RacGTP - WASP - Arp2/3 - branched actin - lamellopodia
41
cdc42 - filopodia
cdc42 - WASP - Arp 2/3 - branched actin - filopodia
42
cdc42 - filopodia
cdc42 - WASP - Arp 2/3 - branched actin - filopodia
43
examples of what CDC42 controls
migrating fibroblast - extending leading edge cytotoxic T cell - contact with target cell, formation strong contact epithelial cell - apical basolateral polarised dividing cell - c.elegans - asymmetric division

Microbiology Essay plans (9 decks)

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