17-Cell Signalling in Human Disease Flashcards
What is the target of cholera toxin?
G-protein called Gs
What enzymes are activated by GPCRs?
Adenyl cyclase
Phospholipase C
How is Cl- secreted into the gut?
G protein becomes active due to addition of activated GPCR causing GDP to become GTP. The G protien activates adenlyl cyclase which converts ATP to cAMP and increases secretion of Cl into gut
What is the role of cholera toxin in causing diarrohea?
Cholera toxin prevents GTP breakdown due to modification of the G protein , keeping Gs in the “on” conformation, triggering excess Cl- secretion
Describe the effect of blocking synaptic signalling on the body
no muscle sensation as neurotransmitter cannot pass and leads to loss of muscle sensation- botox
What is synaptic signalling?
From a nerve cell to a target cell
What does RTK stand for?
Receptor Tyrosine Kinase
What happens when interleukin receptor RTK is overactivated?
Contributes to inflammatory conditions such as Muckle Wells syndrome
What do RTKs control?
Cell growth, cell division and “slower” cellular responses
How does altered chloride ion channels contribute to cystic fibrosis?
Deletion in the gene for the cAMP - dependent chloride channel pump in airway epithelial cells
Epithelial cells can’t pump Cl- out of the cells
Decreases water secretion from the cells
Causes increased viscosity
Patients more prone to bacterial infections because they can’t clear the mucus from their lungs
How is overactive EGF receptor tyrosine kinase signalling invloved in breast cancer?
increase levels of EGF receptor at the PM
