Studying Signalling Paths Flashcards
What are the 2 approaches to studying
Top down from signal to effect
Bottom up from effect to signal
What are the 4 methods used
Purified proteins
Tissue culture
Animal models
Human models
What is using purified proteins Eg to study the interaction between 2 proteins
Overexpression in a system like ecoli then purifying invitro
Is purified proteins easy to manipulate / gain molecular analysis
Yes easily manipulated eg addition of phos groups or removal to see effect
What does clean data from purified proteins mean
Controlled conditions like ph etc
What does clean data allow
Repeated multiple times easily
What is the main disad of purified proteins
Not physiological, the conditions are artificial and in vitro
What needs to be known before using purified proteins
The pathway components
Is it easy to express and purify proteins
No there are some issues with extraction eg if protein becomes insoluble hard to remove or proteins can become inactive in extraction
What is promiscuity in protein purification
When 2 proteins meet which wouldnt in vivo
How is ste5 an example of how to use purified proteins promiscuity
Can be put in with kss1 components and cause the pathway to occur if starvation
What are the 2 types of cell tissue culture
Primary - extracts from human or animal tissue
Cell lines - been immortalised to divide constantly either by Chem treatment or taken from tumour
What are the ads of cell culture
More physiological from human/animal
Clean data- still controlled conditions
Easily manipulated
Many experiments can be done (multiple data points)
What conditions needs to be kept for tissue culture
Co2 and humidity
What are the disads of tissue culture
Not fully physiological eg cell lines Chem treated
Easily infected with bacteria
Expensive
Cells can change over time
Cells might not be pure- may be diff types of cell eg muscle and blood cells
What are ads of using animal models
Cheap
Disease models already available eg ob ob
Physiological to an extent
Is data clean with animal and human models
No, conditions can’t be controlled, other pathways can interfere, compensation occurs (accommodation to conditions)
What are the disads of animal models/ Human
Ethics , not easily repeated/can’t do many experiments on one model, if using cell preps may not be pure and can change, differences between animals, shortage of volunteers
What are the ads of using human models
Truly physiological
Can get feedback on how they feel
Can select people with disease
What is the rat treated with streptozotocin modelling
Streptozotocin destroys B cells which mimics diabetes 1