Dr Prigent's Work Flashcards
What modifications occur in the ER?
Glycosylation
Protein Folding
Sulphide bond formation
What modifications typically occur in the vesicles?
Prohormone processing
Typically proteolytic cleavage
What were the relevance of the pancreatic acinar cells in the discovery of the secretory pathway?
As they are specialised secretory cells with a clear polarized structure they were ideal for visualizing the secretory pathway. Jamieson and Palade used them for their pulse, chase experiment in which slices of guinea pig pancreas were prepared then incubated in a cold leucine free medium with tritiated leucine and allowed to warm to 37C for 3 minutes. This medium was then replaced with a medium containing cold leucine and a chase was ran for varying times from 1-117 minutes.
How was VSV-G used to help outline the secretory pathway?
Temperature sensitive GFP-tagged VSV-G was followed through the pathway in live cells when the temperature was lowered to 32C
How was it shown that secretory proteins were localised to the ER lumen shortly after synthesis?
Cells cultured in 35S methionine was homogenized. Some of the cells were treated with detergent then protease was added, no signal was emittted. Some were treated with protease straight away still emitted a signal.
What are the main types of secreted proteins?
Extracellular matrix proteins
Serum proteins
Hormones
Digestive enzymes
What is required for protein sorting?
A signal sequence at the N-terminus
A receptor
Translocation machinery
