8.18-8.20 Flashcards
TGN is responsible for sorting proteins into vesicles destined for where?
apical vs. basal membranes
basolateral vesicle signal
tyrosine and dileucine-based signals in cytoplasmic domain
apical vesicle signal
no specific cytoplasmic domain signals
- have N/O-linked sugars in lumen domain, or GPI anchors
recycling endosome
subset of early endosome, also capable of sorting molecules
regulated secretion from TGN uses _____________
secretory granules
signal for secretion
secretagogue
synaptotagmin
Ca2+-binding protein that is key player in fusion
what does synaptotagmin do
regulates vesicle secretion by binding to SNARE pairs and holding them in inactive configuration and prevents fusion
what happens to synaptotagmin when nerve impulse triggers release of Ca2+
Ca2+ changes conformation of synaptotagmin, causes it to let go of SNARE complexes, allows membrane fusion
where can ABC transporters be found
ER, Golgi, PM
what does ABC stand for
ATP-binding cassette
where do ABC transporters bind protein
c-face
what energy do ABC transporters use
ATP energy
ex. of proteins that move by ABC transport
interleukins, FGF
types of ABC transporters and uses
- GRASP
- CFTR
- MHC class I antigen presentation
- MDR protein
- chloroquine-resistance
GRASP
Golgi-membrane associated protein - grabs protein from c-face, transports into Golgi
role of ABC transporters in MHC class I antigen presentation
- peptide fragments in cytosol from protease activity
- ABC gets into ER for association with MHC class I
- T-cytotoxic lymphocytes can be activated
CFTR
Cl- channel
where is chloroquine-resistance found
Plasmodium falciparum
chloroquine-resistance
chief cause of malaria, resistance due to ABC transporter exporting drug
what do tetanus and botulinum toxin both target
SNAREs
tetanus and botulinum toxin are both:
zinc proteases
tetanus toxin
causes spastic paralysis:
- inhibits release of inhibitory neurotransmitter GABA by cleaving SNAREs in inhibitory interneurons and preventing vesicle docking
botulinum toxin
causes flaccid paralysis:
- cleaves SNAREs in neurons and prevents release of acetylcholine from neuromuscular junctions
