Vesicular transport Flashcards
What is found in the plasma membrane?
Lipids
Proteins
Sugars
Characteristics of the inside/outside of the plasma membrane
Outside- sugars
Inside- negative charge
What is phosphatidyl serine?
Phospholipid
Strictly found in the inner leaflet
Flips over to the outer surface only upon apoptosis
How is cholesterol taken up by the cells?
Cholesterol transported by LDL
LDL binds to LDL receptors- found in clathrin coated pits
LDL receptors are recycled
What is phosphatidylinositol?
Important as a signalling lipid
What are ER lipida and proteins packaged into?
COP2 vesicles
How are vesicles formed in phagocytosis?
Actin-driven membrane invagination
What do SNARE proteins do?
Fuse membranes together
3 snares fuse
Why is it hard for membranes to fuse?
They must overcome repulsion of the negatively charged membranes
Which SNAREs traverse the membrane?
Syntaxin and synaptobrevin
What happens when SNARE proteins bind?
They form a tight 4 helical coiled coil
What do NSF enzymes do?
They catalyse the dissociation of SNARE coils by hydrolysing ATP
What does the botulinum neurotoxin do?
They attack SNARE proteins- one subunit escapes the vesicle and cleaves a specific SNARE protein- vesicles in the cell cannot fuse with the cell membrane
Which snare proteins travserse the membrane?
Syntaxin
Synaptobrevin
What test can detect phosophotidylserine flipping over?
Fluorescent annexin v test
