TRANSMEMBRANE SIGNALING

Question 1

what are the key fundamentals of transmembrane signaling?

Answer 1

• lipid soluble ligand
• transmembrane receptor protein
• transmembrane receptor that binds and stimulates the intracellular protein tyrosine kinase
• ligand gated transmembrane ion channel
• transmembrane receptor protein that stimulates GTP binding signal transducer G protein, which modulates production of an intracellular second messenger

Question 2

this is a lipid soluble agent used for the intracellular receptors? name examples?

Answer 2

hormones

corticosteroids
mineralcorticoids
sex steroids
vitamin D
thyroid hormone

Question 3

polypeptides consisting of an extracellular hormone binding domain and a cytoplasmic enzyme domain
-protein tyrosine kinase

ligand examples
-insulin, epidermal growth factor

enzyme inhibitors
-trastuzumab

Answer 3

ligand-regulated transmembrane enzymes

Question 4

cytokine receptors

intracellular and extracellular domains that form dimers

ligand examples
-interferons, erythropoietin, growth hormone

Answer 4

ligand-regulated transmembrane, non-enzymes

Question 5

alters electrical potential across the membrane

ligand gated ion channels
-nicotine

voltage gated ion channels
-lidocaine

Answer 5

ion channels

Question 6

3 components

• cell surface receptor
• GTP binding protein or G protein
• effector changes the concentration of the second messenger

examples
-alpha and beta adrenoceptors, glucagon receptors, thyrotropin receptors, dopamine, serotonin receptors, acetylcholine

Answer 6

G proteins