Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

ANAT 262 > Secretory pathway I > Flashcards

Secretory pathway I Flashcards

(76 cards)

Start Studying
1
Q

Describe er - organization of secretory pathway

A

Continuous with outer nuclear membrane
Everywhere where mts are - uses mts to extend to edge of cell

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

Describe golgi - organization of secretory pathway

A

Mtoc - neg end

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

Centrioles

A

Near of end of mts - within centrosomes

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

If move towards - end mt

A

= towards golgi

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

Describe secretory pathway - gen types

A

Er to Golgi
Recycling = Golgi to er
Intra Golgi (inside)
Golgi to cell surface, secretory granules, endosomes

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

Describe er—> golgi basically

A

From er =deliver cargo to cis Golgi
Always fuses with Golgi at cis face

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

Cis golgi

A

Entry

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

Golgi

A

Has polarity

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

Trans Golgi

A

Exit face
Have trans Golgi network

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

Name the 4 steps in vesicular trafficking

A

Sorting of cargo, budding and separation from source membrane
Transfer to destination
Storage - like in some cases in like synaptic vesicles
Recognition of target membrane and fusion

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

Describe cop 2 -er to Golgi

A

Vesicles budding and uncoating

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

What can cop 2 recognize = name signals

A

Can recognize various signals on cytoplasmic domains of proteins
1 = 2 phenylalanines at c term of protein
2 = cluster of acidic aas (has to be cytoplasmic, but does not need to be at end c term)

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

Describe fusion of cop 2 vesicles

A

Makes vesicular tubular intermediates (vtc) or pre Golgi intermediates
Happens next to er - not much movement of cop 2 vesicles

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

How does Vtc move

A

Movement of pre Golgi intermediate to Golgi using dynein and mts

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

What happens to vtc

A

Fusion of pre Golgi intermediates with Golgi

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

Er —> Golgi all steps

A

1 = Cop 2 vesicle budding, uncoating
Fusion of cop 2 vesicles to make vtc
2 = movement of pre Golgi intermediate to Golgi using dynein and mts
3 = fusion of vtc with golgi

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

Golgi —> er all steps

A

4 = Budding cop 1 vesicles
Retrograde trafficking
Fusion of cop 1 vesicles to er

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

Describe cop 2 coat = image

A

Coat recruits cargo - cargo that has to domains can interact with coat
Coat = binds cytoplasmic domains of Tom proteins, and concentrates them in bud
Then eventually have to uncoat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

When cop 1

A

Golgi to er

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

When cop 2

A

Er to Golgi

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

When tubular transport intermediate

A

Golgi to er
Or
Golgi to cell surface

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

Describe clathrin - gen

A

More complicated
Endocytosis at cell surface
Budding form trans Golgi
Budding from endosome

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

Describe cop 2 structure- image

A

Naturally wants to be curved - not flat
Assembled in test tube =
Cop 2 exerts force on membrane that tried to curve it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How does cop 2 form a vesicle

A

Cop 2 subunits (2 major subunits) found in cytoplasm
Must be brought to er membranes to assemble and form a coat
Must be released after vesicle budding complete

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Describe cop 2 structure specifically
2 subunits = sec 23/24 inner, sec13/31 outer
26
Describe sec12
Gef= guanine nt exchange factor Found in er membrane, not evenly spread, sec 12 concentrated in er exit sites and not really elsewhere Purpose = brings sar 1 to membrane and swaps gdp for gap
27
Describe sar 1
Floats in cytoplasm, has hydrophobic patch = can bind membrane, sar1-gdp = off When sar1-gtp= attached to membrane and on,binds and recruits other proteins If sar1 hydrolysis gtp = pops of membrane (Ras super fam, 100-150 gtpases)
28
What does sar 1 bind
Sec23/24 from cytoplasm = recognizes signals (2 phenylalanines in a row at cterm OR cluster acidic aas - not close to end, either type 1 or type 2 tm proteins)
29
What does sec 13/31 bind
Sec 23/24 on membrane Sec 13/31 = causes membrane curvature = drives vesicle formation, allows budding (Induces conformational change in sec 23/24 and causes sar1 to hydrolysis gtp = sar1 comes off and destabilizes and removes coat = AFTER VESICLE BUDS )
30
What is sar1
SMALL gtpase On membrane in gtp bound form, can bind inner cop2 (sec23/24) Cop 2 uncoating can occur after sar hydrolzyes gtp= after buds
31
Inner cop 2 subunit
Recognizes cargo
32
Outer cop 2 subunit
Required for budding
33
Role of sar1 gtpase in cop 2 = 6 whole steps
1 = sar 1 gdp in cytoplasm loaded into Membrane by sec 12 gef, also loads. Sar1 with gtp 2 = sar1 gtp on membrane recruits inner subunits cop2 (sec23/24) which can recruit cargo 3 = sec 23/24 binds sec13/31 = forces membrane curvature and budding 4 = sar 1 gtp hydrolyzes it’s gtp, sar 1 gdp unstable in any mmervane and leaves - very quickly 5 = without sar 1 - cop2 coat leaves vesicle membrane = uncoating vesicle - bit slower 6 = uncoated vesicle fuses with vtc membranes
34
Describe p115
Tethering protein Cop 2 vesicles formed at ever exit sites = are clustered together by the action of the Golgi tethering factor p115 = binds vesicles together = 1st step
35
What recruits p115
Rab1 gtpase recruits p115 onto these vesicles
36
What happens to vesicles after tethered - p115
Tethered vesicles then fuse in an nsf and snare dependent mechanism to form vtcs = 2nd step
37
Describe cargo drawn
Tm protein s which have cytoplasmic domain which can interact with cop 2
38
Describe er exit sites
Lots of sec12 = lots of sar1 recruited Many vesicles bud and fuse
39
Describe vtc
Vesicles - coated in cop2 = move by Brownian motion = not too far Then fuse to form pre Golgi intermediate Cop 1 , arf coats vtc
40
How does the cell solve the problem of cargoes which cannot cross the membrane, and therefore cannot interact directly with COPII?
Like if not tm protein - if luminal = Must use CARGO RECEPTORSSS
41
Describe cargo proteins
PROTEINS Tm Have cytoplasmic tail that crosses membrane =can interact with cop2 and recruit luminal proteins Most cells secrete proteins or enzymes that have no tm domains os bind cargo recpetors
42
Describe er resident proteins
Not supposed to leave er Sometimes caught in vesicle by accident So there’s mechanism to recognize protein in Golgi and send back to er
43
What happens to cargo receptors after done job
Need to recycle them = recycle from Golgi back to er = retrograde pathway from Golgi —> er
44
What cannot interact directly with cop 2
Er proteins lacking tm domains
45
What do er proteins lacking Tm domains do
Mustinteract with tm proteins called cargo receptors that do interact with cop 2
46
Describe ex of cargo receptor - ergic53
Binds n linked oligosaccharides Proteins n linked glycosylated - trio of sugars added - multiple mannoses Interact with ergic53 = provides signal for leaving er Most proteins that leave er = n linked glycosylated
47
What do many cargo receptors have to the ability to do
Ability to interact with cop1 (Including ergic53)
48
Describe cargo receptors interaction motifs
Several exist Most common is 2 lysines followed by other 2 aas at c term of protein
49
Describe ergic53 - structure
Ends with kkff (2 lysines, 2 phenylalanines) = 2 Lysines interact with cop1 The 2 c term phenylalanines = powerful cop 2 binding signal = provides signal to leave er and to be returned to er
50
Describe transfer to destination
Pre Golgi intermediates Transfer to Golgi on mt
51
What are names for pre Golgi intermediates
Vtc - vesicular tubular complex Pre Golgi intermediate Ic - intermediate compartment
52
What are pre Golgi intermediates
Complex of tubules - often tipped with cop1 coats Believed to be formed by fusion of many cop2 vesicles with each other
53
Describe cop1 vesicles containing cargo receptors
Bud off vtcs and fuse with nearby er = return empty cargo receptors and some other retrograde cargo back to er
54
Arf1
Same role for cop1 that sar1 plays for cop2
55
Describe images of vtc
Big - fraction of micron Dot in lm See more in ‘em Bind to mts
56
How do vtc move
As a whole moves to Golgi Most likely dynein used to target to - end mt = it need exp to confirm
57
what does dynein do
Transport vtc to Golgi on mts
58
Describe dynein and dynactin stuff
Dynactin = links to vesicle, dynactin binds dynein and dyenin binds mt If overexpress = complex falls apart
59
Where does dynein move towards
Moves towards neg end = er to golgi
60
Where do kinesins move towards
Move towards + end (typically)
61
Describe exps - involving movement across mts
15 degrees, viral protein tagged with gfp Put on stage 37 degrees Gets bigger and bigger Move to Golgi in relatively straight lines If repeats exp with mt depolarizer = nothing happens, no movement
62
Fusion with cis Golgi = steps 1-3
Step 1 = tethering (tethering proteins - Golgins, ex p115, binds rab1)= one p115 on each cop2 vesicle = then fuse Step 2= snare proteins interact Step 3 = membranes fuse
63
What controls tethering proteins or snares
Common for tethering proteins to be controlled by rabs
64
What facilitates vtc docking with cis Golgi - explains
Interaction between rab1-p115 complex on vtcs and gm130-grasp65 on cis Golgi Gm130= one possible tethering protein, if block = fine bc many alternatives But if block p115 = no er—> golfi traffic *imporatnt protein
65
Describe model o describe how membrane tethering by gm130 and p115 are linked to snare assembly and fusion
V snare on vesicle membrane T snare on target membrane Right v and t snares have to interact = bind tightly = bring membranes together, destabilize membranes and causes them to fuse
66
Describe ex of snares driving membranes closer together before fusion
Many = forms a ring and destabilizes membranes in middle of ring
67
Describe Golgi to er trafficking - gen
Retrograde Some proteins sent from er to Golgi (cargo receptors, v snares - tm need to be recycled) = back to er for reuse = retrograde pathway Golgi —> er
68
How many Golgi to er retrograde pathways exist
2 pathways
69
Describe cop 1 dependent retrograde trafficking
Employs cop1 coated vesicles Mostly for proteins that are recycled back to er Can recycle from vtc directly or from Golgi Travel short
70
Describe cop 1 independent retrograde trafficking pathway
Pathway involved formation of tubular transport intermediates and does not need cop1 Mostly lipids recycled back to er
71
Describe cop 1 - role
Role controversial - may have more than one Responsible for vtc —> er and also Golgi —> er trafficking May also be involved in trafficking inside Golgi
72
What does cop 1 bind to
Dilysine - kkxx motifs foun don er/Golgi resident proteins
73
Describe tubular retrograde transport intermediates
Cop1 independent pathway Tubular retrograde transport intermediates Depends on rab6 Recycling lipids - move lots of lipids from er —> Golgi but for some cells like pancreatic cells that are secreting like crazy = ships to of er faster than can make it so have to have lots of recycling to er
74
Gap - after budding
Sec23/24 = gap after budding
75
Name snares
Syntaxin 5 = t snared needed for fusion of vtcs with cig Golgi Others = v snare sec22b, and t snares rbet1 and gos28
76
What does not use retrograde pathway
Tethers - recruited form cytoplasm so recycled diff

ANAT 262 (24 decks)

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