Sorting, the RER, and the Golgi Flashcards Preview

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Flashcards in Sorting, the RER, and the Golgi Deck (28)
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1

Signal peptides

N-terminal extensions composed of 5-30 basic/hydrophobic AA

2

Signal patches

Distant parts of protein sequence brought together upon folding

3

Types of translocation

Post-translationally (C)
Co-translationally (N)

4

Post-translational translocation characteristics

SOluble and posses patch or signal peptide

5

Sorting into the nucleus

Uses NLS (short, basic squences on N-terminus of proteins)
Importin comes in with protein, uses Ran-GTP to get out

6

Sorting into mitochondria process

Precursors protein with MTS...binds receptor...moves to protein translocator...pulled into protein and signal sequence cleaved by peptidase

7

Sorting into mitochondrial membrane

Matrix targeting sequence binds TOM protein of outer...pulls through into TIM...TIM recognizes the intermembrane space-targeting sequence and diffuses over to protease...protease will cleave the matrix targeting sequence and the intermembrane space targeting seqence stays in inner membrane

8

Intermembrane space sorting

Intermembrane space targeting sequences pass through Tom receptor

9

Outer membrane mitochondrial proteins sorting

Hydrophobic transmembrane signal...recognized by TOM, passed to SAM, mim and mdm act and released into membrane

10

Peroxisomes sorting process

C-terminal and N-terminal ends...peroxisomal targeting sequence binds pex5 receptor...receptor binds pex14 receptor on membrane...moves through via pex 10 and 12

11

Co-translational translocation

Used for proteins that are secreted, membrane bound, resident in ER, golgi, or lysosomes

12

Signal for co-translational translocation

N-terminal signal of hydrophobic residues

13

Process of co-translational location

SRP binds to N terminal signal sequence...SRP binds to SRP receptor on ER membrane surface associated with translocon...GTPase activity of both SRP and SRP receptor results in opening of the translocon...signal peptidase claves the signal sequence

14

What is attached into the ER

N-linked glycosylation
Linked to asparagine - X - serine/threonine

15

What is in the ER membrane that holds the glycosylation chain?

Dolichol

16

Glucosidase

Chews the oligosaccharide attached to the protein

17

ERAD system

Sends misfolded proteins for degradation

18

Glycosylated proteins that pass ERAD

Encapsulated in transition vesicles and transported via anterograde transporrt

19

Surface of vesicles from ER t oGOlgi coated with

COP2

20

Modifications in Golgi

O-linked oligo added to serines and threonines
Mannose-6-P added to proteins goign to lysosomes

21

Cis golgi network

Phosphorylation of oligosaccharides on lysosomal

22

Cis cisterna

Removal of Man

23

Medial cisterna

Removal of man and addition of GlcNAc

24

Trans cisterna

Additon of Gal

25

Trans GOlgi netowkr

Addition of NANA (common sialic acid)
And sortint

26

Glycosylation purposes

Sorting
Stabilization of secreted proteins and transmembrane with extracellular domains
Biomolecule recognition

27

Golgi to lysosomes

Binds to M6P receptor...travels in vesicle with clathrin coat to the early endosome...M6P dissociated...Endosome fuses to lysosome

Receptor recycled

28

Secretory vs. transport vesicles

Secretory - regulated exocytosis
Transport - constitutive exocytosis