Principles of Receptor Biology Flashcards
What are examples of receptors that are sensitive to inverse agonists?
Benzodiazepine
Histamine
Opoid
Cannabinoid
Dopamine
Bradykinin
Adenosine receptors
NOTE: The constitutive activity of some receptors is sensitive to the activity of these inverse agonists
By what mechanism does direct activation of transcription take place?
- Transmembrane receptor releases transcription factors 2.Transcription factors undergo proteolytic cleavage and liberate a cytosolic fragment
- Fragment enters the nucleus and modulates gene activation
Examples of ion channel plasma membrane receptors
- ACh on nicotinic cholinergic receptor
- Norepi on K+ channel in the heart
What are examples of ligands that act via cytoplasmic or nuclear receptors to increase transciption of selected mRNAs?
- Thyroid hormones
- Retinoic acid
- Steroid hormones
What are examples of ligands that act of rectors that activate phospholipase C?
- Angiotensin II
- Norepeinephrine via a1-adrenergic receptor
- Vasopressin via V1 receptor
Examples of ligands that bind to receptors and increase cGMP in cell?
Atrial natiuretic peptide
Nitric oxide
Examples of ligands that increase tyrosine kinase activity
Insulin
EGF
PDGF
M-CSF
Examples of ligands that increase serine or threonine kinase activity
TGF-B
Activin
Inhibin
Kinases catalyze the phosphorylation of which residues in proteins?
Serine, Threonine, and Tyrosine
Examples of ligands that bind nuclear receptors
Steroid Hormones
- Mineralocorticoids
- Glucocorticoids
- Androgens
- Estrogens
- Progestins
Miscellaneous Hormones
- Thyroid
- Vitamin D
- Retinoic acid
- Prostaglandins
NOTE: These ligands bind to regulatory sequences in DNA and increase or decrease gene transcription
Function of phospholipase C
Converts PIP2 to IP3 and DAG
NOTE: PLC is activated by tyrosine kinase receptors
___________ releases arachidonic acid from membrane phospholipids.
Phospholipase A2
What enzymes are activated by arachidonic acid release?
Cycloxygenases
- Clotting
- Formation of Thromboxane and Prostacyclins
5- Lipoxygenase
- Inflammatory response
Epoxygenase
*
What are the five families of monomeric G-proteins and what is the function of each?
Ras
- Regulate gene expression and cell proliferation, differentiation and survival
Rho
- Regulate actin cytoskeletal organization, cell cycle progression and gene expression
Rab
- Regaulate intravesicular transport and trafficking of proteins between organelles in the secretiory and endocytotic pathways
Ran
- Regulate nucleocytoplasmic transport of RNA and proteins
Arf
- Regulates vesicular transport (similar to Rab)
