Intracellular Compartments and Vesicular Transport Flashcards
COPI
Lysosome to Golgi (retrograde)
COPII
Golgi to Lysosome (anterograde)
Clatherin
Golgi to Plasma membrane
Assembly of protein coats
Sar1 paints the membrane to facilitate the addition of the protein coats for vesicular transport. Sar1-GDP is the soluble form that is not associated with the membrane but once the Sar1-GEF gets a hold of the Sar1-GDP it exchanges the GDP for GTP which leads to the integration of Sar1 into the membrane to allow for that painting. Sar1-GAP exchanges GTP for GDP returning to the soluble form once again. Sar1 is used for COPII while Arf is used for COPI- they both have the same mechanism.
Clatherin Assembly
The cargo binds a receptor and the receptor is bound to the adaptor proteins and these adaptor proteins serve as the mediator for the addition of the clatherin coat.
Dynamin
Dynamin is a snake-like structure that assists in the vesicle budding off from the membrane.
Mutations in LDL Receptor Causing Atherosclerotic Diseases
Mutations in the LDL receptor does not cause the cargo (cholesterol) to not bind- it still binds to cholesterol but it is unable to bind to the adaptor proteins so that the clatherin coat is unable to form so the cholesterol ends up in the circulatory system- which can lead to the formation of the atheroscerotic plaques in the vessels.
Constitutive Endocytosis
This is the unregulated form of endocytosis- these vesicles have unregulated fusion with the plasma membrane.
Regulated Endocytosis
Is the regulated form of endocytosis that involves secretory vesicles. These vesicles are only able to fuse with the plasma membrane after there has been a signal (hormone or neurotransmitter) that says its okay to release its contents through the plasma membrane of its target.
Using Phosphoinositides to identify distinct organelles
PI phosphorylation is different in distinct organelles so that you are able to recognize what organelle it is based on its style of phosphorylation.
Describe the function of NSF and ATP in the recycling (re-use) or v- and t- SNAREs
NSF pries apart the identical pairs of v-SNAREs and t-SNAREs in both membranes. ATP helps translocate the v-SNAREs via vesicular transportation so they are able to be used in another vesicle process.
Botulism Toxin
It is a protease that cleaves the SNAREs which leads to the temporary paralysis of muscle because nothing else can no longer fuse to the membrane since the SNAREs are needed for membrane fusion.
