Lecture 16 - Active learning session Flashcards
If there is no IgG circulating but lots in the ER what would you do?
Work out where in the secretory pathway is blocked. Machinery involved could be SNAREs, the chaperones etc. It could be a problem forming a COPII vesicle. This could include adaptor proteins (SEC23/4), GTPases, coat proteins. These could all be targeted to identify whether it’s a folding issue or a trafficking issue. You can target them by introducing mutations. Dominant negative proteins - small GTPases - can be locked in GDP state. Dominant negative form of SAR1, which is GDPase needed to form COPII vesicle, introduced into a normal cell, you might get an accumulation of IgG. You can establish the patient has this defect through western blot to identify a mutation in protein translation
What is a rescue experiment?
A protein is knocked down with sRNA and an effect is observed. You can them put back in sRNA-resistant form of the gene, as this will show specificity - being able to rescue a defect. This is a rescue experiment
How could a rescue experiment be used to find out if a lack of SEC23 is to blame for a lack of circulating IgG?
If you did this to the patient, you can knock-out a component (e.g. SEC23), and insert a wild-type protein. If the process is rescued, then you can associate the lack of circulation of the IgG to this gene mutation.
Could carry this out in models - e,g, mice, drosophila, yeast or zebra
