13 - Membrane trafficking in disease Flashcards
What is the role of adaptor proteins?
- They recognise and select cargo ensuring specificity via the signals they give off.
- They also play an important role in linking the coat to the ER membrane.
What is AP2?
Its a major Clathrin adaptor protein that recognises sorting signals.
What do reconstitution experiments allow us to do?
they allow us to understand what makes us a COPII vesicle?
What needs to be added to a reconstitution experiment to measure the presence of the COPII vesicle?
ATP, GTP and cytosol.
How is the presence of COPII measured in reconstitution experiments?
By the presence of the cargo protein p58.
What is the issue around packaging large cargo?
Defects in the COPII vesicle formation causes problems with the packaging of collagen due to its size, so collagen filaments cannot fit in the vesicle.
How are defects in COPII managed to fit large cargo?
Modifications are made to the COPII coat to help organise collagen into tubular structures to help sort the cargo.
What is the role of Rab in its GTP form?
It helps to recruit a tethering protein at either end, this tether helps to facilitate the SNARE complexes to form by pulling the vesicle close to the membrane.
What do Rab cascades allow for?
Movement of cargo between organelles.
Why would Rab5 be activated ?
Because of its GEFs where it works on the endosome, when cargo is selected to go to the late endosome the GAP for Rab5 can recruit the GEF for RAB7.
What disease can a Rab7a mutation cause?
Charcot Marie Tooth 2B - causes excessive activation of the protein, causing a reduced autophagic reflux and inhibition of neurite growth.
What disease is caused by the harnessing of a Rab protein?
Legionella pneumophilia, it can recruit RAb1 to the cell surface to create an ER like component so it can replicate.
