What is cell signaling?
- When cells communicate:
- with their environment:
Phagocytosis.
Eat and get rid of waste
Share Plasmids
Etc.
What are the types of cell communication?
1.) - When cells communicate:
- with their environment:
Phagocytosis.
Eat and get rid of waste
Share Plasmids
Etc.
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2.) With each other:
- Multicellular organisms
- Microbial communities
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Why study cell signaling?
*.) - Fundamental to living organisms:
- Essential to life, homeostasis
-Development
- Immunity
- Movement
-etc.
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*.) Diseases occur when signaling is faulty:
- Cystic fibrosis
- paralysis
- cancer
- Diabetes
- Etc.
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*.) Drug development:
- 40% of all medicinal drugs block GPCR
Superfamily alone
What are the general steps in cell signaling?
- ) Signal reception
- ) Singal processings
* with amplification - ) Signal Response
- ) Signal deactivation
What is the driving force of cell signaling?
Conformation changes propagate signaling pathways.
T/F cells can have different signals inside and outside the membrane?
T, depending on the area of the cell the signal is trying to reach will dictate the make of that signaler.
- sometimes they need to bind to a receptor and other times they can just enter.
What dictates whether or not a signal needs to bind to a receptor or not?
- Polarity
- Small polar (maybe) hydrophobic molecules enter the cell without a receptor
- hydrophilic molecules bind to a receptor to enter.
Parts of signaling pathway?
- initiates change of state of the pathway
- Turn on/off
- Can be lipids, proteins, small molecules, even gases
- Downstream mediators
- Often are proteins
- Change the shape or alter to propagate signals
- Second messengers
- small molecules
- Signal amplification
- Final response
- Often a transcription factor, metabolic protein, or cytoskeleton
t/f: one molecule affects the next in cell signaling?
- True, like dominos
How does each molecule affect the next?
- Conformation changes!!
- changes in shape make proteins more attractive to binding partners
- .. or open and close a gate to change location
What do second messengers do?
Amplification
- They are small, and hundreds can be released at once.
Describe the pathway in the virtual lab?
- ) Signal binds to the receptor
- ) Receptor activates G Protein
- ) G protein recruits/activates adenylyl/cyclase protein
- ) Adenylyl cyclase converts ATP to cAMP
- ) cAMP activates PKA protein
- ) PKA activates a second kinase protein
- ) The kinase activates glycogen phosphorylase enzyme
- ) glycogen phosphorylase helps us break down glycogen to release stored energy between meals
t/f each signal can have multiple effects?
true
Adrenaline is known as….?
epinephrine
What are the effects of epinephrine?
- Sugar breakdown
- increased heart rate
- hypertension
- expanding blood pressure
- expanding the lungs
- enlarging the pupil in the eye
- redistributing blood to the muscle
what are the cell signaling techniques?
- Blocking kinases with inhibitors
- Reporter assays:
- the dye used on bacteria in the lab
- Cell behavior assays
- example differences in cytoskeletal elements, shape, matrix,etc.
- Biochemistry
- look for a specific protein and study what happened
Western blot analysis:
Separates proteins via size, and detects via antibodies
Calcium assay:
The use of fluorescence to defect calcium ( secondary messenger) in the pathway
Migration Assay:
Detects the gap and then how cells move to fill the gap.
- scratch is made via a micropipettes
