LEcture 8

Question 1

2 main functions of Golgi Apparatus

Answer 1

Sorts proteins (lipids) destined for TGN (main site of sorting)
Modifies N- and O-linked oligos (Carbohydrate factory)

Question 2

Chlamydomonas

Answer 2

has beautiful Golgi

Question 3

Why does Golgi cis and trans stain differently?

Answer 3

They stain differently because their biochemically compartmentalized

Question 4

Cis Golgi

Answer 4

Phosphorylation of lysosomal enzumes

Question 5

Medial

Answer 5

Removal of Mannose
Addition of GlcNAc

Question 6

Trans

Answer 6

Addition of Galactose and Sialic Acid

Question 7

2 types of Golgi Proteins and where are they found

Answer 7

Type I: has N-terminus at lumen found in TGN
Type II: has N-terminus at cytosol intra-golgi and are Glycosylation enzymes

Question 8

How is Type II localized?

Answer 8

Hypothesis is Kin recognition. They associate with their own proteins and form higher-oligomer structure. cis and cis
This is not possible as they can’t enter vesicle due to size constraints

Question 9

FLIP

Answer 9

Fluorescene Loss in Photobleaching
-used to study connectivity

Question 10

FRAP

Answer 10

Fluorescence Gain After Photobleaching
-used to study diffusion (time)

Question 11

Why is Kin recognition dead?

Answer 11

Using FLIP, they found Golgi enzymes diffusing freely and rapidly with intra-Golgi network

Question 12

Fluorescence Microscopy

Answer 12

Uses immunofluorescence to image tagged proteins using antibodies

Question 13

Indirect IF and its advantages

Answer 13

unlabeled primary antibody allows multiple secondary (use different species for antigen)

Question 13

Purpose of Fixing cells and 3 chemicals to use

Answer 13

Fixing is to maintain cell structure and antigenicity
Formaldehyde is reversible but weak
Methanol is organic and denatures proteins
Acetone is organic and preserves proteins

Question 14

confocal Microscopy

Answer 14

Pinhole allows pixel by pixel good quality

Question 15

Compartments of Golgi

Answer 15

cis
medial
trans
TGN
ERGIC

Question 16

ERGIC
temperature

Answer 16

ER-Golgi Intermediate Compartment
at 15C it accumulates secreted proteins

Question 17

Microtubules function

Answer 17

They guide ERGIC to Golgi from transitional (tER)

Question 18

Golgi160 and Dynein

Answer 18

Golgi160 is the tether for dynein and ERGICis microtubule-dependent motor

Question 19

Membrane Traffic COP

Answer 19

COPII exits from ER to ERGIC
COPI present in ERGIC and brings back to ER

Question 20

Brefeldin A, COPI, and Golgi

Answer 20

BFA inhibits exchange factor GEF of Arf1 which cannot recruit COPI to Golgi
Golgi fuses with ER and when BFA is washed Golgi reappears

Question 21

3 Hypothesis for Golgi Function

Answer 21

Standard Model
Maturation Model
Intra-Golgi Recycling